We address how the interplay between the finite availability and carrying capacity of particles at different parts of a spatially extended system can control the steady-state currents and density profiles in the one-dimensional current-carrying lanes connecting the different parts of the system. To study this, we set up a minimal model consisting of two particle reservoirs of the same finite carrying capacity connected by two equally sized antiparallel totally asymmetric simple exclusion processes (TASEPs). We focus on the steady-state currents and particle density profiles in the two TASEP lanes. The ensuing phases and the phase diagrams, which can be remarkably complex, are parametrized by the model parameters defining particle exchange between the TASEP lanes and the reservoirs and the filling fraction of the particles that determine the total resources available. These parameters may be tuned to make the densities of the two TASEP lanes globally uniform or piece-wise continuous in the form of a combination of a single localized domain wall and a spatially constant density or a pair of delocalized domain walls. Our model reveals that the two reservoirs can be preferentially populated or depopulated in the steady states.

A recent evaluation of three-loop nonplanar Feynman integrals contributing to Higgs plus jet production has established their dependence on two novel symbol letters. We show that the resulting alphabet is described by a G₂ cluster algebra, enlarging the C₂ cluster algebra found to cover all previously known integrals relevant for this process. The cluster algebra connection we find reveals new adjacency relations, which significantly reduce the function space dimension of the non-planar triple ladder integral. These adjacencies may be understood in part by embedding G₂ inside higher-rank cluster algebras.

In a classical scattering problem, the classical eikonal is defined as the generator of the canonical transformation that maps in-states to out-states. It can be regarded as the classical limit of the log of the quantum S-matrix. In a classical analog of the Born approximation in quantum mechanics, the classical eikonal admits an expansion in oriented tree graphs, where oriented edges denote retarded/advanced worldline propagators. The Magnus expansion, which takes the log of a time-ordered exponential integral, offers an efficient method to compute the coefficients of the tree graphs to all orders. We exploit a Hopf algebra structure behind the Magnus expansion to develop a fast algorithm which can compute the tree coefficients up to the 12th order (over half a million trees) in less than an hour. In a relativistic setting, our methods can be applied to the post-Minkowskian (PM) expansion for gravitational binaries in the worldline formalism. We demonstrate the methods by computing the 3PM eikonal and find agreement with previous results based on amplitude methods. Importantly, the Magnus expansion yields a finite eikonal, while the naïve eikonal based on the time-symmetric propagator is infrared-divergent from 3PM on.

We performed a systematic search for strong gravitational lenses using Hyper Suprime-Cam (HSC) imaging data, focusing on galaxy-scale lenses combined with an environment analysis resulting in the identification of lensing clusters. To identify these lens candidates, we exploited our residual neural network from HOLISMOKES VI (Cañameras et al. 2021, A&A, 653, L6), trained on realistic gri mock-images as positive examples, and real HSC images as negative examples. Compared to our previous work, where we successfully applied the classifier to around 62.5 million galaxies having an i-Kron radius of ≥0.8″, we now lowered the i-Kron radius limit to ≥0.5″. The result in an increase by around 73 million sources, amounting to a total of over 135 million images. During our visual multi-stage grading of the network candidates, we also simultaneously inspected larger stamps (80″ × 80″) to identify large, extended arcs cropped in the 10″ × 10″ cutouts and also classify their overall environment. Here, we also re-inspected our previous lens candidates with i-Kron radii of ≥0.8″ and classified their environment. Using the 546 visually identified lens candidates, we further defined various criteria by exploiting extensive and complementary photometric redshift catalogs to select the candidates in overdensities. In total, we identified 24 grade A and 138 grade B exhibit either spatially-resolved multiple images or extended, distorted arcs in the new sample. Furthermore, combining our different techniques to determine overdensities, we identified a total 231/546 lens candidates by at least one of our three identification methods for overdensities. This new sample contains only 49 group- or cluster-scale re-discoveries, while 43 systems had been identified by all three procedures. Furthermore, we performed a statistical analysis by using the neural network from HOLISMOKES IX (Schuldt et al. 2023a, A&A, 671, A147) to model these systems as singular isothermal ellipsoids with external shear and to estimate their parameter values, making this the largest uniformly modeled sample to date. We find a tendency towards larger Einstein radii for galaxy-scale systems in overdense environments, while the other parameter values as well as the uncertainty distributions are consistent between those in overdense and non-overdense environments. These results demonstrate the feasibility of downloading and applying neural network classifiers to hundreds of million cutouts, which will be needed in the upcoming era of big data from deep, wide-field imaging surveys such as Euclid and the Rubin Observatory Legacy Survey of Space and Time. At the same time, it offers a sample size that can be visually inspected by humans. These deep learning pipelines, with false-positive rates of ∼0.01%, are very powerful tools to identify such rare galaxy-scale strong lensing systems, while also aiding in the discovery of new strong lensing clusters.

The Hubble tension is one of the most relevant unsolved problems in cosmology today. Strongly gravitationally lensed transient objects, such as strongly lensed supernovae, are an independent and competitive probe that can be used to determine the Hubble constant. In this context, the time delay between different images of lensed supernovae is a key ingredient. We present a method to retrieve time delays and the amount of differential dust extinction between multiple images of lensed type IIP supernovae (SNe IIP) through their color curves, which display a kink in the time evolution. With several realistic mock color curves based on an observed SN (not strongly lensed) from the Carnegie Supernova Project (CSP), our results show that we can determine the time delay with an uncertainty of approximately ± 1.0 days. This is achievable with light curves with a 2-day time interval and up to 35% missing data due to weather-related losses. Accounting for additional factors such as microlensing, seeing, shot noise from the host and lens galaxies, and blending of the SN images would likely increase the estimated uncertainties. Differentiated dust extinction is more susceptible to uncertainties because it depends on imposing the correct extinction law. Further, we also investigate the kink structure in the color curves for different rest-frame wavelength bands, particularly rest-frame ultraviolet (UV) light curves from the Neil Gehrels Swift Observatory (SWIFT), finding sufficiently strong kinks for our method to work for typical lensed SN redshifts that would redshift the kink feature to optical wavelengths. With the upcoming Rubin Observatory Legacy Survey of Space and Time (LSST), hundreds of strongly lensed supernovae will be detected, and our new method for lensed SN IIP is readily applicable to provide delays.

Jet observables at hadron colliders feature "super-leading" logarithms, double-logarithmic corrections resulting from a breakdown of color coherence due to complex phases in hard-scattering amplitudes. While these effects only arise in high orders of perturbation theory and are suppressed in the large-N_c limit, they formally constitute leading logarithmic corrections to the cross sections. We present the first analysis of the corresponding contributions to a hadronic cross section, including all partonic channels and interference effects. Interestingly, some interference terms in partonic <inline-formula id="IEq1"><mml:math display="inline" id="IEq1_Math"><mml:mi>q</mml:mi><mml:mover accent="true"><mml:mi>q</mml:mi><mml:mo stretchy="true">¯</mml:mo></mml:mover></mml:math></inline-formula> → <inline-formula id="IEq2"><mml:math display="inline" id="IEq2_Math"><mml:mi>q</mml:mi><mml:mover accent="true"><mml:mi>q</mml:mi><mml:mo stretchy="true">¯</mml:mo></mml:mover></mml:math></inline-formula> scattering are only linearly suppressed in 1/N_c. Our results for the pp → 2 jets gap-between-jets cross section demonstrate the numerical importance of super-leading logarithms for small values of the veto scale Q₀, showing that these contributions should be accounted for in precision studies of such observables.

Star-galaxy separation is a crucial step in creating target catalogues for extragalactic spectroscopic surveys. A classifier biased towards inclusivity risks including high numbers of stars, wasting fibre hours, while a more conservative classifier might overlook galaxies, compromising completeness and hence survey objectives. To avoid bias introduced by a training set in supervised methods, we employ an unsupervised machine learning approach. Using photometry from the Wide Area VISTA Extragalactic Survey (WAVES)-Wide catalogue comprising nine-band <inline-formula><tex-math id="TM0001" notation="LaTeX">$u - K_s$</tex-math></inline-formula> data, we create a feature space with colours, fluxes, and apparent size information extracted by PROFOUND. We apply the non-linear dimensionality reduction method UMAP (Uniform Manifold Approximation and Projection) combined with the classifier HDBSCAN (Hierarchical Density-Based Spatial Clustering of Applications with Noise) to classify stars and galaxies. Our method is verified against a baseline colour and morphological method using a truth catalogue from Gaia, SDSS (Sloan Digital Sky Survey), GAMA (Galaxy And Mass Assembly), and DESI (Dark Energy Spectroscopic Instrument). We correctly identify 99.75 per cent of galaxies within the AB magnitude limit of <inline-formula><tex-math id="TM0002" notation="LaTeX">$Z=21.2$</tex-math></inline-formula>, with an F1 score of <inline-formula><tex-math id="TM0003" notation="LaTeX">$0.9971 \pm 0.0018$</tex-math></inline-formula> across the entire ground truth sample, compared to <inline-formula><tex-math id="TM0004" notation="LaTeX">$0.9879 \pm 0.0088$</tex-math></inline-formula> from the baseline method. Our method's higher purity (<inline-formula><tex-math id="TM0005" notation="LaTeX">$0.9967 \pm 0.0021$</tex-math></inline-formula>) compared to the baseline (<inline-formula><tex-math id="TM0006" notation="LaTeX">$0.9795 \pm 0.0172$</tex-math></inline-formula>) increases efficiency, identifying 11 per cent fewer galaxy or ambiguous sources, saving approximately 70 000 fibre hours on the 4MOST (4-m Multi-Object Spectroscopic Telescope) instrument. We achieve reliable classification statistics for challenging sources including quasars, compact galaxies, and low surface brightness galaxies, retrieving 92.7 per cent, 84.6 per cent, and 99.5 per cent of them, respectively. Angular clustering analysis validates our classifications, showing consistency with expected galaxy clustering, regardless of the baseline classification.

Aims. We introduce a novel sub-resolution prescription to correct for the unresolved dynamical friction (DF) onto black holes (BHs) in cosmological simulations, to describe BH dynamics accurately, and to overcome spurious motions induced by numerical effects. Methods. We implemented a sub-resolution prescription for the unresolved DF onto BHs in the OpenGadget3 code. We carried out cosmological simulations of a volume of (16 comoving Mpc)³ and zoomed-in simulations of a galaxy group and of a galaxy cluster. We assessed the advantages of our new technique in comparison to commonly adopted methods for hampering spurious BH displacements, namely repositioning onto a local minimum of the gravitational potential and ad hoc boosting of the BH particle dynamical mass. We inspected variations in BH demography in terms of offset from the centres of the host sub-halos, the wandering population of BHs, BH–BH merger rates, and the occupation fraction of sub-halos. We also analysed the impact of the different prescriptions on individual BH interaction events in detail. Results. The newly introduced DF correction enhances the centring of BHs on host halos, the effects of which are at least comparable with those of alternative techniques. Also, the correction becomes gradually more effective as the redshift decreases. Simulations with this correction predict half as many merger events with respect to the repositioning prescription, with the advantage of being less prone to leaving substructures without any central BH. Simulations featuring our DF prescription produce a smaller (by up to ~50% with respect to repositioning) population of wandering BHs and final BH masses that are in good agreement with observations. Regarding individual BH–BH interactions, our DF model captures the gradual inspiraling of orbits before the merger occurs. By contrast, the repositioning scheme, in its most classical renditions, describes extremely fast mergers, while the dynamical mass misrepresents the dynamics of the black holes, introducing numerical scattering between the orbiting BHs. Conclusions. The novel DF correction improves the accuracy if tracking BHs within their hosts galaxies and the pathway to BH- BH mergers. This opens up new possibilities for better modeling the evolution of BH populations in cosmological simulations across different times and different environments.

Within $Z^\prime$ models, neutral meson mixing severely constrains beyond the Standard Model (SM) effects in flavour changing neutral current (FCNC) processes. However, in certain regions of the $Z^\prime$ parameter space, the contributions to meson mixing observables become negligibly small even for large $Z^\prime$ couplings. While this a priori allows for significant new physics (NP) effects in FCNC decays, we discuss how large $Z^\prime$ couplings in one neutral meson sector can generate effects in meson mixing observables of other neutral mesons, through correlations stemming from $\text{SU(2)}_L$ gauge invariance and through Renormalization Group (RG) effects in the SM Effective Field Theory~(SMEFT). This is illustrated with the example of $B_s^0-\bar B_s^0$ mixing, which in the presence of both left- and right-handed $Z^\prime bs$ couplings $\Delta_L^{bs}$ and $\Delta_R^{bs}$ remains SM-like for $\Delta_R^{bs}\approx 0.1\,\Delta_L^{bs}$. We show that in this case, large $Z^\prime bs$ couplings generate effects in $D$ and $K$ meson mixing observables, but that the $D$ and $K$ mixing constraints and the relation between $\Delta_R^{bs}$ and $\Delta_L^{bs}$ are fully compatible with a lepton flavour universality~(LFU) conserving explanation of the most recent $b\to s\ell^+\ell^-$ experimental data without violating other constraints like $e^+ e^-\to\ell^+\ell^-$ scattering. Assuming LFU, invariance under the $\text{SU(2)}_L$ gauge symmetry leads then to correlated effects in $b\to s\nu\bar\nu$ observables presently studied intensively by the Belle~II experiment, which allow to probe the $Z^\prime$ parameter space that is opened up by the vanishing NP contributions to $B_s^0-\bar B_s^0$ mixing. In this scenario the suppression of $B\to K(K^*)\mu^+\mu^-$ branching ratios implies {\em uniquely} enhancements of $B\to K(K^*)\nu\bar\nu$ branching ratios up to $20\%$.

Stable 205Tl ions have the lowest known energy threshold for capturing electron neutrinos (ve) of Eve≥50.6  keV. The Lorandite Experiment (LOREX), proposed in the 1980s, aims at obtaining the longtime averaged solar neutrino flux by utilizing natural deposits of Tl-bearing lorandite ores. To determine the ve capture cross section, it is required to know the strength of the weak transition connecting the ground state of 205Tl and the 2.3 keV first excited state in 205Pb. The only way to experimentally address this transition is to measure the bound-state beta decay (ßb) of fully ionized 205Tl81+ ions. After three decades of meticulous preparation, the half-life of the ßb decay of 205Tl81+ has been measured to be 291−27+33   days using the Experimental Storage Ring (ESR) at GSI, Darmstadt. The longer measured half-life compared to theoretical estimates reduces the expected signal-to-noise ratio in the LOREX, thus challenging its feasibility.

We discuss the relation between the Koonin-Pratt femtoscopic correlation function (CF) and invariant mass distributions from production experiments. We show that the equivalence is total for a zero source-size and that a Gaussian finite-size source provides a form-factor for the virtual production of the particles. Motivated by this remarkable relationship, we study an alternative method to the Koonin-Pratt formula, which connects the evaluation of the CF directly with the production mechanisms. The differences arise mostly from the <inline-formula><mml:math display="inline"><mml:mi>T</mml:mi></mml:math></inline-formula>–matrix quadratic terms and increase with the source size. We study the case of the <inline-formula><mml:math display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:msup><mml:mi>D</mml:mi><mml:mrow><mml:mo>*</mml:mo><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math></inline-formula> and <inline-formula><mml:math display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>D</mml:mi><mml:mrow><mml:mo>*</mml:mo><mml:mn>0</mml:mn></mml:mrow></mml:msup></mml:math></inline-formula> correlation functions of interest to unravel the dynamics of the exotic <inline-formula><mml:math display="inline"><mml:msub><mml:mi>T</mml:mi><mml:mrow><mml:mi>c</mml:mi><mml:mi>c</mml:mi></mml:mrow></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:mn>3875</mml:mn><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mo>+</mml:mo></mml:msup></mml:math></inline-formula>, and find that these differences become quite sizable already for 1 fm sources. We nevertheless conclude that the lack of coherence in high-multiplicity-event reactions and in the creation of the fire-ball source that emits the hadrons certainly make much more realistic the formalism based on the Koonin-Pratt equation. We finally derive an improved Lednicky-Lyuboshits (LL) approach, which implements a Lorentz ultraviolet regulator that corrects the pathological behavior of the LL CF in the punctual source-size limit.

Inspired by earlier results on recursions for open-string tree-level amplitudes, and by a result of Brown and Dupont relating open- and closed-string tree-level amplitudes via single-valued periods, we identify a recursive relation for closed-string tree-level amplitudes. We achieve this by showing that closed-string analogues of Selberg integrals satisfy the Knizhnik-Zamolodchikov equation for a suitable matrix representation of the free Lie algebra on two generators, and by identifying the limits at z=1 and z=0, which are related by the Deligne associator, with N-point and (N-1)-point closed-string amplitudes, respectively.

A quantitative spectroscopic study of blue supergiant stars in the Hubble constant anchor galaxy NGC 4258 is presented. The non-LTE analysis of Keck I telescope LRIS spectra yields a central logarithmic metallicity (in units of the solar value) of [Z] = ‑0.05 ± 0.05 and a very shallow gradient of ‑(0.09 ± 0.11) r/r ₂₅ with respect to galactocentric distance in units of the isophotal radius. Good agreement with the mass–metallicity relationship of star-forming galaxies based on stellar absorption line studies is found. A comparison with H II region oxygen abundances obtained from the analysis of strong emission lines shows reasonable agreement when the M. Pettini & B. E. J. Pagel calibration is used, while the D. Zaritsky et al. calibration yields values that are 0.2–0.3 dex larger. These results allow us to put the metallicity calibration of the Cepheid period–luminosity relation in this anchor galaxy on a purely stellar basis. Interstellar reddening and extinction are determined using Hubble Space Telescope and JWST photometry. Based on extinction-corrected magnitudes, combined with the stellar effective temperatures and gravities we determine, we use the flux-weighted gravity–luminosity relationship to estimate an independent spectroscopic distance. We obtain a distance modulus m ‑ M = 29.38 ± 0.12 mag, in agreement with the geometrical distance derived from the analysis of the water maser orbits in the galaxy's central circumnuclear disk.

HD 54879 is the most recently discovered magnetic O-type star. Previous studies ruled out a rotation period shorter than 7 yr, implying that HD 54879 is the second most slowly rotating known magnetic O-type star. We report new high-resolution spectropolarimetric measurements of HD 54879, which confirm that a full stellar rotation cycle has been observed. We derive a stellar rotation period from the longitudinal magnetic field measurements of <inline-formula> </inline-formula> days (about 7.02 yr). The radial velocity of HD 54879 has been stable over the last decade of observations. We explore equivalent widths and longitudinal magnetic fields calculated from lines of different elements, and conclude the atmosphere of HD 54879 is likely chemically homogeneous, with no strong evidence for chemical stratification or lateral abundance nonuniformities. We present the first detailed magnetic map of the star, with an average surface-magnetic-field strength of 2954 G, and a strength for the dipole component of 3939 G. There is a significant amount of magnetic energy in the quadrupole components of the field (23%). Thus, we find HD 54879 has a strong magnetic field with a significantly complex topology.

Large angular scale surveys in the absence of atmosphere are essential for measuring the primordial B-mode power spectrum of the Cosmic Microwave Background (CMB). Since this proposed measurement is about three to four orders of magnitude fainter than the temperature anisotropies of the CMB, in-flight calibration of the instruments and active suppression of systematic effects are crucial. We investigate the effect of changing the parameters of the scanning strategy on the in-flight calibration effectiveness, the suppression of the systematic effects themselves, and the ability to distinguish systematic effects by null-tests. Next-generation missions such as LiteBIRD, modulated by a Half-Wave Plate (HWP), will be able to observe polarisation using a single detector, eliminating the need to combine several detectors to measure polarisation, as done in many previous experiments and hence avoiding the consequent systematic effects. While the HWP is expected to suppress many systematic effects, some of them will remain. We use an analytical approach to comprehensively address the mitigation of these systematic effects and identify the characteristics of scanning strategies that are the most effective for implementing a variety of calibration strategies in the multi-dimensional space of common spacecraft scan parameters. We verify that LiteBIRD's standard configuration yields good performance on the metrics we studied. We also present Falcons.jl, a fast spacecraft scanning simulator that we developed to investigate this scanning parameter space.

We present a novel multi-messenger approach for probing nonstandard neutrino properties through the detection of gravitational waves (GWs) from collapsing stellar cores and associated supernova explosions. We show that neutrino flavor conversion inside the proto-neutron star (PNS), motivated by physics Beyond the Standard Model (BSM), can significantly boost PNS convection. This effect leads to large-amplitude GW emission over a wide frequency range during an otherwise relatively quiescent GW phase shortly after core bounce. Such a signal provides a promising new avenue for exploring nonstandard neutrino phenomena and other BSM physics impacting PNS convection.

Even in the absence of neutrino masses, a neutrino gas can exhibit a homogeneous flavor instability that leads to a periodic motion known as the fast flavor pendulum. A well-known necessary condition is a crossing of the angular flavor lepton distribution. However, in contrast to an earlier finding by two of us, the Nyquist criterion inspired by plasma physics, while being a more restrictive necessary condition, is not always sufficient. The question depends on the unstable branch of the dispersion relation being bounded by critical points that both lie under the light cone (points with subluminal phase velocity), in which case the Nyquist criterion is sufficient. While the lepton-number angle distribution, assumed to be axially symmetric, easily allows one to determine the real branch of the dispersion relation and to recognize if instead superluminal critical points exist, this graphical method does not translate into a simple instability condition. We discuss the dispersion relation for the homogeneous mode in the more general context of modes with arbitrary wave number and stress that it plays no special role on this continuum, except for its regular but fragile long-term behavior owed to its many symmetries.

We present ultraviolet, optical, and near-infrared photometric and optical spectroscopic observations of the luminous fast blue optical transient (LFBOT) CSS 161010:045834–081803 (CSS 161010). The transient was found in a low-redshift (z = 0.033) dwarf galaxy. The light curves of CSS 161010 are characterized by an extremely fast evolution and blue colors. The V-band light curve shows that CSS 161010 reaches an absolute peak of <inline-formula> </inline-formula> mag in 3.8 days from the start of the outburst. After maximum, CSS 161010 follows a power-law decline ∝t ^‑2.8±0.1 in all optical bands. These photometric properties are comparable to those of well-observed LFBOTs such as AT 2018cow, AT 2020mrf, and AT 2020xnd. However, unlike these objects, the spectra of CSS 161010 show a remarkable transformation from a blue and featureless continuum to spectra dominated by very broad, entirely blueshifted hydrogen emission lines with velocities of up to 10% of the speed of light. The persistent blueshifted emission and the lack of any emission at the rest wavelength of CSS 161010 are unique features not seen in any transient before CSS 161010. The combined observational properties of CSS 161010 and its M _* ∼ 10⁸ M _⊙ dwarf galaxy host favor the tidal disruption of a star by an intermediate-mass black hole as its origin.

We assess the capabilities of the LiteBIRD mission to map the hot gas distribution in the Universe through the thermal Sunyaev-Zeldovich (SZ) effect. Our analysis relies on comprehensive simulations incorporating various sources of Galactic and extragalactic foreground emission, while accounting for the specific instrumental characteristics of the LiteBIRD mission, such as detector sensitivities, frequency-dependent beam convolution, inhomogeneous sky scanning, and 1/f noise. We implement a tailored component-separation pipeline to map the thermal SZ Compton y-parameter over 98% of the sky. Despite lower angular resolution for galaxy cluster science, LiteBIRD provides full-sky coverage and, compared to the Planck satellite, enhanced sensitivity, as well as more frequency bands to enable the construction of an all-sky thermal SZ y-map, with reduced foreground contamination at large and intermediate angular scales. By combining LiteBIRD and Planck channels in the component-separation pipeline, we also obtain an optimal y-map that leverages the advantages of both experiments, with the higher angular resolution of the Planck channels enabling the recovery of compact clusters beyond the LiteBIRD beam limitations, and the numerous sensitive LiteBIRD channels further mitigating foregrounds. The added value of LiteBIRD is highlighted through the examination of maps, power spectra, and one-point statistics of the various sky components. After component separation, the 1/f noise from LiteBIRD's intensity channels is effectively mitigated below the level of the thermal SZ signal at all multipoles. Cosmological constraints on S ₈ = σ ₈ (Ω_m /0.3)^0.5 obtained from the LiteBIRD-Planck combined y-map power spectrum exhibits a 15 % reduction in uncertainty compared to constraints derived from Planck alone. This improvement can be attributed to the increased portion of uncontaminated sky available in the LiteBIRD-Planck combined y-map.

The goal of this paper is to make a connection between tropical geometry, representations of quantum affine algebras, and scattering amplitudes in physics. The connection allows us to study important and difficult questions in these areas: (1)We give a systematic construction of prime modules (including prime non-real modules) of quantum affine algebras using tropical geometry. We also introduce new objects which generalize positive tropical Grassmannians.(2)We propose a generalization of Grassmannian string integrals in physics, in which the integrand is a product indexed by prime modules of a quantum affine algebra. We give a general formula of u-variables using prime tableaux (corresponding to prime modules of quantum affine algebras of type A) and Auslander–Reiten quivers of Grassmannian cluster categories.(3)We study limit g-vectors of cluster algebras. This is another way to obtain prime non-real modules of quantum affine algebras systematically. Using limit g-vectors, we construct new examples of non-real modules of quantum affine algebras. We give a systematic construction of prime modules (including prime non-real modules) of quantum affine algebras using tropical geometry. We also introduce new objects which generalize positive tropical Grassmannians. We propose a generalization of Grassmannian string integrals in physics, in which the integrand is a product indexed by prime modules of a quantum affine algebra. We give a general formula of u-variables using prime tableaux (corresponding to prime modules of quantum affine algebras of type A) and Auslander–Reiten quivers of Grassmannian cluster categories. We study limit g-vectors of cluster algebras. This is another way to obtain prime non-real modules of quantum affine algebras systematically. Using limit g-vectors, we construct new examples of non-real modules of quantum affine algebras.

This report summarizes the work of the EMMI Rapid Reaction Task Force on "Real and Virtual Photon Production at Ultra-Low Transverse Momentum and Low Mass at the LHC". We provide an overview of the soft-photon puzzle, i.e., of the long-standing discrepancy between experimental data and predictions based on Low's soft-photon theorem, also referred to as "anomalous" soft photon production, and we review the current theoretical understanding of soft radiation and soft theorems. We also focus on low-mass dileptons as a tool for determining the electrical conductivity of the medium produced in high-energy nucleus–nucleus collisions. We discuss how both topics can be addressed with the planned ALICE 3 detector at the LHC.

The stellar haloes of dwarf galaxies are becoming an object of interest in the extragalactic community due to their detection in some recent observations. Additionally, new cosmological simulations of very high resolution were performed, allowing their study. These stellar haloes could help shed light on our understanding of the assembly of dwarf galaxies and their evolution, and allow us to test the hierarchical model for the formation of structures at small scales. We aim to characterise the stellar haloes of simulated dwarf galaxies and analyse their evolution and accretion history. We use a sample of 17 simulated galaxies from the Auriga Project with a stellar mass range from 3.28x10^8 Msun to 2.08x10^10 Msun. We define the stellar halo as the stellar material located outside an ellipsoid with semi-major axes equal to 4 times the half light radius (Rh) of each galaxy. We find that the inner regions of the stellar halo (4 to 6 times the Rh) are dominated by in-situ material. For the less massive simulated dwarfs (M*<=4.54x10^8 Msun), this dominance extends to all radii. We find that this in-situ stellar halo is mostly formed in the inner regions of the galaxies and then ejected into the outskirts during interactions and merger events. In ~50% of the galaxies, the stripped gas from satellites contributed to the formation of this in-situ halo. The stellar haloes of the galaxies more massive than M*>=1x10^9 Msun are dominated by the accreted component beyond 6 Rh. We find that the more massive dwarf galaxies accrete stellar material until later times (t90~4.44 Gyr ago, being t90 the formation time) than the less massive ones (t90~8.17 Gyr ago), impacting on the formation time of the accreted stellar haloes. The galaxies have a range of 1 to 7 significant progenitors contributing to their accreted component but there is no correlation between this quantity and the galaxies' accreted mass.

A novel coalescence process is shown to take place in plasma fluid simulations, leading to the formation of large-scale magnetic islands that become dynamically important in the system. The parametric dependence of the process on the plasma $\beta$ and the background magnetic shear is studied, and the process is broken down at a fundamental level, allowing to clearly identify its causes and dynamics. The formation of magnetic-island-like structures at the spatial scale of the unstable modes is observed quite early in the non-linear phase of the simulation for most cases studied, as the unstable modes change their structure from interchange-like to tearing-like. This is followed by a slow coalescence process that evolves these magnetic structures towards larger and larger scales, adding to the large-scale tearing-like modes that already form by direct coupling of neighbouring unstable modes, but remain sub-dominant without the contribution from the smaller scales through coalescence. The presence of the cubic non-linearities retained in the model is essential in the dynamics of this process. The zonal fields are key actors of the overall process, acting as mediators between the competitive mechanisms from which Turbulence Driven Magnetic Islands can develop. The zonal current is found to slow down the formation of large-scale magnetic islands, acting as an inhibitor, while the zonal flow is needed to allow the system to transfer energy to the larger scales, acting as a catalyst for the island formation process.

Brown dwarfs are the bridge between low-mass stars and giant planets. One way of shedding light on their dominant formation mechanism is to study them at the earliest stages of their evolution, when they are deeply embedded in their parental clouds. Several works have identified pre- and proto-brown dwarfs candidates using different observational approaches. The aim of this work is to create a database with all the objects classified as very young substellar candidates in the litearature in order to study them in an homogeneous way. We have gathered all the information about very young substellar candidates available in the literature until 2020. We have retrieved their published photometry from the optical to the centimeter regime, and we have written our own codes to derive their bolometric temperatures and luminosities, and their internal luminosities. We have also populated the database with other parameters extracted from the literature, like e.g. the envelope masses, their detection in some molecular species, and presence of outflows. The result of our search is the SUCANES database, containing 174 objects classified as potential very young substellar candidates in the literature. We present an analysis of the main properties of the retrieved objects. Since we have updated the distances to several star forming regions, this has allowed us to reject some candidates based on their internal luminosities. We have also discussed the derived physical parameters and envelope masses for the best substellar candidates isolated in SUCANES. As an example of a scientific exploitation of this database, we present a feasibility study for the detection of radiojets with upcoming facilities: the ngVLA and the SKA interferometers. The SUCANES database is accessible through a Graphical User Interface and it is open to any potential user.

While supervised neural networks have become state of the art for identifying the rare strong gravitational lenses from large imaging data sets, their selection remains significantly affected by the large number and diversity of non-lens contaminants. This work evaluates and compares systematically the performance of neural networks in order to move towards a rapid selection of galaxy-scale strong lenses with minimal human input in the era of deep, wide-scale surveys. We used multiband images from PDR2 of the Hyper-Suprime Cam (HSC) Wide survey to build test sets mimicking an actual classification experiment, with 189 securely-identified strong lenses from the literature over the HSC footprint and 70 910 non-lens galaxies in COSMOS covering representative lens-like morphologies. Multiple networks were trained on different sets of realistic strong-lens simulations and non-lens galaxies, with various architectures and data preprocessing, mainly using the deepest gri-bands. Most networks reached excellent area under the Receiver Operating Characteristic (ROC) curves on the test set of 71 099 objects, and we determined the ingredients to optimize the true positive rate for a total number of false positives equal to zero or 10 (TPR₀ and TPR₁₀). The overall performances strongly depend on the construction of the ground-truth training data and they typically, but not systematically, improve using our baseline residual network architecture presented in Paper VI (Cañameras et al., A&A, 653, L6). TPR₀ tends to be higher for ResNets (≃ 10–40%) compared to AlexNet-like networks or G-CNNs. Improvements are found when (1) applying random shifts to the image centroids, (2) using square-root scaled images to enhance faint arcs, (3) adding z-band to the otherwise used gri-bands, or (4) using random viewpoints of the original images. In contrast, we find no improvement when adding g – αi difference images (where α is a tuned constant) to subtract emission from the central galaxy. The most significant gain is obtained with committees of networks trained on different data sets, with a moderate overlap between populations of false positives. Nearly-perfect invariance to image quality can be achieved by using realistic PSF models in our lens simulation pipeline, and by training networks either with large number of bands, or jointly with the PSF and science frames. Overall, we show the possibility to reach a TPR₀ as high as 60% for the test sets under consideration, which opens promising perspectives for pure selection of strong lenses without human input using the Rubin Observatory and other forthcoming ground-based surveys.

Metals in the diffuse, ionized gas at the boundary between the Milky Way's interstellar medium (ISM) and circumgalactic medium, known as the disk–halo interface (DHI), are valuable tracers of the feedback processes that drive the Galactic fountain. However, metallicity measurements in this region are challenging due to obscuration by the Milky Way ISM and uncertain ionization corrections that affect the total hydrogen column density. In this work, we constrain ionization corrections to neutral hydrogen column densities using precisely measured electron column densities from the dispersion measures of pulsars that lie in the same globular clusters as UV-bright targets with high-resolution absorption spectroscopy. We address the blending of absorption lines with the ISM by jointly fitting Voigt profiles to all absorption components. We present our metallicity estimates for the DHI of the Milky Way based on detailed photoionization modeling of the absorption from ionized metal lines and ionization-corrected total hydrogen columns. Generally, the gas clouds show a large scatter in metallicity, ranging between 0.04 and 3.2 Z _⊙, implying that the DHI consists of a mixture of gaseous structures having multiple origins. We estimate the inflow and outflow timescales of the DHI ionized clouds to be 6–35 Myr. We report the detection of an infalling cloud with supersolar metallicity that suggests a Galactic fountain mechanism, whereas at least one low-metallicity outflowing cloud (Z < 0.1 Z _⊙) poses a challenge for Galactic fountain and feedback models.

A generalization of Wilson line operators at subleading power in the soft expansion has been recently introduced as an efficient building block of gravitational scattering amplitudes for non-spinning objects. The classical limit in this picture corresponds to the strict Regge limit, where the Post-Minkowskian (PM) expansion corresponds to the soft expansion, interpreted as a sum over correlations of soft emissions. Building on the well-studied worldline model with ${\cal N}=1$ supersymmetry, in this work we extend the generalized Wilson line (GWL) approach to the case of spinning gravitating bodies. Specifically, at the quantum level we derive from first-principles a representation for the spin $1/2$ GWL that is relevant for the all-order factorization of next-to-soft gravitons with fermionic matter, thus generalizing the exponentiation of single-emission next-to-soft theorems. At the classical level, we identity the suitable generalization of Wilson line operators that enables the generation of classical spin observables at linear order in spin. Thanks to the crucial role played by the soft expansion, the map from Grassmann variables to classical spin is manifest. We also comment on the relation between the GWL approach and the Worldline Quantum Field Theory as well as the Heavy Mass Effective Theory formalism. We validate the approach by rederiving known results in the conservative sector at 2PM order.

Multi-messenger observations of astrophysical transients provide powerful probes of the underlying physics of the source as well as beyond the Standard Model effects. We explore transients that can occur in the vicinity of supermassive black holes at the center of galaxies, including tidal disruption events (TDEs), certain types of blazars, or even supernovae. In such environments, the dark matter (DM) density can be extremely high, resembling a dense spike or core. We study a novel effect of neutrino diffusion sustained via frequent scatterings off DM particles in these regions. We show that for transients occurring within DM spikes or cores, the DM-neutrino scattering can delay the arrival of neutrinos with respect to photons, but this also comes with a suppression of the neutrino flux and energy loss. We apply these effects to the specific example of TDEs, and demonstrate that currently unconstrained parameter space of DM-neutrino interactions can account for the sizable $O$(days) delay of the tentative high-energy neutrinos observed from some TDEs.

Cosmic shear, galaxy clustering, and the abundance of massive halos each probe the large-scale structure of the universe in complementary ways. We present cosmological constraints from the joint analysis of the three probes, building on the latest analyses of the lensing-informed abundance of clusters identified by the South Pole Telescope (SPT) and of the auto- and cross-correlation of galaxy position and weak lensing measurements (3$\times$2pt) in the Dark Energy Survey (DES). We consider the cosmological correlation between the different tracers and we account for the systematic uncertainties that are shared between the large-scale lensing correlation functions and the small-scale lensing-based cluster mass calibration. Marginalized over the remaining $\Lambda$CDM parameters (including the sum of neutrino masses) and 52 astrophysical modeling parameters, we measure $\Omega_\mathrm{m}=0.300\pm0.017$ and $\sigma_8=0.797\pm0.026$. Compared to constraints from Planck primary CMB anisotropies, our constraints are only 15% wider with a probability to exceed of 0.22 ($1.2\sigma$) for the two-parameter difference. We further obtain $S_8\equiv\sigma_8(\Omega_\mathrm{m}/0.3)^{0.5}=0.796\pm0.013$ which is lower than the Planck measurement at the $1.6\sigma$ level. The combined SPT cluster, DES 3$\times$2pt, and Planck datasets mildly prefer a non-zero positive neutrino mass, with a 95% upper limit $\sum m_\nu<0.25~\mathrm{eV}$ on the sum of neutrino masses. Assuming a $w$CDM model, we constrain the dark energy equation of state parameter $w=-1.15^{+0.23}_{-0.17}$ and when combining with Planck primary CMB anisotropies, we recover $w=-1.20^{+0.15}_{-0.09}$, a $1.7\sigma$ difference with a cosmological constant. The precision of our results highlights the benefits of multiwavelength multiprobe cosmology.

Muon conversion is one of the best probes of charged lepton flavor violation. The experimental limit is soon expected to improve by four orders of magnitude, thus calling for precise predictions on the theory side. Equally important are precise predictions for muon decay-in-orbit, the main background for muon conversion. While the calculation of electromagnetic corrections to the two processes above the nuclear scale does not involve significant challenges, it becomes substantially more complex below that scale due to multiple scales, bound-state effects and experimental setup. Here, we present a systematic framework that addresses these challenges by resorting to a series of effective field theories. Combining Heavy Quark Effective Theory (HQET), Non-Relativistic QED (NRQED), potential NRQED, Soft-Collinear Effective Theory I and II, and boosted HQET, we derive a factorization theorem and present the renormalization group equations. Our framework allows for the proper calculation of precise predictions for the rates of the two processes, with crucial implications for the upcoming muon conversion searches. We also provide the most accurate prediction of the signal shape for those searches.

We describe an algorithm to organize Feynman integrals in terms of their infrared properties. Our approach builds upon the theory of Landau singularities, which we use to classify all configurations of loop momenta that can give rise to infrared divergences. We then construct bases of numerators for arbitrary Feynman integrals, which cancel all singularities and render the integrals finite. Through the same analysis, one can also classify so-called evanescent and evanescently finite Feynman integrals. These are integrals whose vanishing or finiteness relies on properties of dimensional regularization. To illustrate the use of these integrals, we display how to obtain a simpler form for the leading-color two-loop four-gluon scattering amplitude through the choice of a suitable basis of finite integrals. In particular, when all gluon helicities are equal, we show that with our basis the most complicated double-box integrals do not contribute to the finite remainder of the scattering amplitude.

Context. Milky Way star clusters provide important clues about the history of star formation in our Galaxy. However, the dust in the disk and in the innermost regions hides them from the observers. Aims. Our goal is twofold. First, to detect new clusters – we have applied the newest methods of detecting clusters with the best available wide-field sky surveys in the mid-infrared because they are the least affected by extinction. Second, we address the question of cluster detection's completeness, for now limiting it to the most massive star clusters. Methods. This search is based on the mid-infrared Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE), to minimize the effect of dust extinction. The search Ordering Points To Identify the Clustering Structure (OPTICS) clustering algorithm was applied to identify clusters, after excluding the bluest, presumably foreground sources, to improve the cluster-to-field contrast. The success rate for cluster identification was estimated with a semi-empirical simulation that adds clusters, based on the real objects, to the point source catalog, to be recovered later with the same search algorithm that was used in the search for new cluster candidates. As a first step, this was limited to the most massive star clusters with a total mass of ~10⁴ M_⊙. Results. Our automated search, combined with inspection of the color-magnitude diagrams and images, yielded 659 cluster candidates; 106 of these appear to have been previously identified, suggesting that a large hidden population of star clusters still exists in the inner Milky Way. However, the search for the simulated supermassive clusters achieves a recovery rate of 70–95%, depending on the distance and extinction toward them. Conclusions. The new candidates – if confirmed – indicate that the Milky Way still harbors a sizeable population of unknown clusters. However, they must be objects of modest richness, because our simulation indicates that there is no substantial hidden population of supermassive clusters in the central region of our Galaxy.

We investigate the interaction between a shock-driven hot wind and a cold multi-cloud layer, for conditions commonly found in interstellar and circumgalactic gas. We present a method for identifying distinct clouds using a Friends-of-Friends algorithm. This approach unveils novel detailed information about individual clouds and their collective behaviour. By tracing the evolution of individual clouds, our method provides comprehensive descriptions of cloud morphology, including measures of the elongation and fractal dimension. Combining the kinematics and morphology of clouds, we refine previous models for drag and entrainment processes. Our by-cloud analysis allows to discern the dominant entrainment processes at different times. We find that after the initial shock passage, momentum transfer due to condensation becomes increasingly important, compared to ram pressure, which dominates at early times. We also find that internal motions within clouds act as an effective dynamic pressure that exceeds the thermal pressure by an order of magnitude. Our analysis shows how the highly efficient cooling of the warm mixed gas at temperatures $\sim 10^{5}$ K is effectively balanced by the kinetic energy injected by the hot wind into the warm and cold phases via shocks and shear motions. Compression-driven condensation and turbulence dissipation maintain a multi-phase outflow and can help explain the presence of dense gas in galaxy-scale winds. Finally, we show that applying our Friends-of-Friends analysis to $\rm{H}_\rm{I}$-emitting gas and correcting for beam size and telescope sensitivity can explain two populations of $\rm{H}_\rm{I}$ clouds within the Milky-Way nuclear wind as structures pertaining to the same outflow.

Modern spectroscopic surveys can only target a small fraction of the vast amount of photometrically cataloged sources in wide-field surveys. Here, we report the development of a generative artificial intelligence (AI) method capable of predicting optical galaxy spectra from photometric broadband images alone. This method draws from the latest advances in diffusion models in combination with contrastive networks. We pass multiband galaxy images into the architecture to obtain optical spectra. From these, robust values for galaxy properties can be derived with any methods in the spectroscopic toolbox, such as standard population synthesis techniques and Lick indices. When trained and tested on 64 × 64 pixel images from the Sloan Digital Sky Survey, the global bimodality of star-forming and quiescent galaxies in photometric space is recovered, as well as a mass–metallicity relation of star-forming galaxies. The comparison between the observed and the artificially created spectra shows good agreement in overall metallicity, age, Dn4000, stellar velocity dispersion, and E(B ‑ V) values. Photometric redshift estimates of our generative algorithm can compete with other current, specialized deep learning techniques. Moreover, this work is the first attempt in the literature to infer velocity dispersion from photometric images. Additionally, we can predict the presence of an active galactic nucleus up to an accuracy of 82%. With our method, scientifically interesting galaxy properties, normally requiring spectroscopic inputs, can be obtained in future data sets from large-scale photometric surveys alone. The spectra prediction via AI can further assist in creating realistic mock catalogs.

The leading and next-to-leading order QCD predictions for Higgs boson pair production at hadron colliders suffer from a significant mass renormalisation scheme uncertainty related to the choice of the top-quark mass. The functional dependence of the result on the value of the intermediate quark mass can be understood in the high-energy limit using the Method of Regions and the tools of Soft-Collinear Effective Theory. In this work, we study the origin of the sizeable logarithmic mass corrections in the $gg \to HH$ amplitudes at leading and next-to-leading power in the limit $s,|t|,|u| \gg m_t^2 \gg m_H^2$. We argue that the mass corrections follow a predictable factorised pattern that can be exploited to simplify their computation. We present results for the leading power leading logarithmic corrections, our analysis leads to a significant reduction in the theoretical uncertainty of the double Higgs production amplitudes at high-energy due to the top-quark mass scheme.

Dense neutrino gases can exhibit collective flavor instabilities, triggering large flavor conversions that are driven primarily by neutrino-neutrino refraction. One broadly distinguishes between fast instabilities that exist in the limit of vanishing neutrino masses, and slow ones, that require neutrino mass splittings. In a related series of papers, we have shown that fast instabilities result from the resonant growth of flavor waves, in the same way as turbulent electric fields in an unstable plasma. Here we extend this framework to slow instabilities, focusing on the simplest case of an infinitely homogeneous medium with axisymmetric neutrino distribution. The relevant length and time scales are defined by three parameters: the vacuum oscillation frequency $\omega_E=\delta m^2/2E$, the scale of neutrino-neutrino refraction energy $\mu=\sqrt{2}G_F(n_\nu+n_{\overline\nu})$, and the ratio between lepton and particle number $\epsilon=(n_\nu-n_{\overline\nu})/(n_\nu+n_{\overline\nu})$. We distinguish between two very different regimes: (i) For $\omega_E\ll \mu \epsilon^2$, instabilities occur at small spatial scales of order $(\mu\epsilon)^{-1}$ with a time scale of order $\epsilon \omega_E^{-1}$. This novel branch of slow instability arises from resonant interactions with neutrinos moving along the axis of symmetry. (ii) For $\mu \epsilon^2\ll \omega_E\ll \mu$, the instability is strongly non-resonant, with typical time and length scales of order $1/\sqrt{\omega_E \mu}$. Unstable modes interact with all neutrino directions at once, recovering the characteristic scaling of the traditional studies of slow instabilities. In the inner regions of supernovae and neutron-star mergers, the first regime may be more likely to appear, meaning that slow instabilities in this region may have an entirely different character than usually envisaged.

Making inferences about physical properties of the Universe requires knowledge of the data likelihood. A Gaussian distribution is commonly assumed for the uncertainties with a covariance matrix estimated from a set of simulations. The noise in such covariance estimates causes two problems: it distorts the width of the parameter contours, and it adds scatter to the location of those contours which is not captured by the widths themselves. For non-Gaussian likelihoods, an approximation may be derived via Simulation-Based Inference (SBI). It is often implicitly assumed that parameter constraints from SBI analyses, which do not use covariance matrices, are not affected by the same problems as parameter estimation with a covariance matrix estimated from simulations. We investigate whether SBI suffers from effects similar to those of covariance estimation in Gaussian likelihoods. We use Neural Posterior and Likelihood Estimation with continuous and masked autoregressive normalizing flows for density estimation. We fit our approximate posterior models to simulations drawn from a Gaussian linear model, so that the SBI result can be compared to the true posterior. We test linear and neural network based compression, demonstrating that neither methods circumvent the issues of covariance estimation. SBI suffers an inflation of posterior variance that is equal or greater than the analytical result in covariance estimation for Gaussian likelihoods for the same number of simulations. The assumption that SBI requires a smaller number of simulations than covariance estimation for a Gaussian likelihood analysis is inaccurate. The limitations of traditional likelihood analysis with simulation-based covariance remain for SBI with a finite simulation budget. Despite these issues, we show that SBI correctly draws the true posterior contour given enough simulations.

Transmission spectroscopy is a prime method to study the atmospheres of extrasolar planets. We obtained a high-resolution spectral transit time series of the hot Jupiter WASP-121 b with CRIRES+ to study its atmosphere via transmission spectroscopy of the He I λ10833 triplet lines. Our analysis shows a prominent He I λ10833 absorption feature moving along with the planetary orbital motion, which shows an observed, transit-averaged equivalent width of approximately 30 mÅ, a slight redshift, and a depth of about 2%, which can only be explained by an atmosphere overflowing its Roche lobe. We carried out 3D hydrodynamic modeling to reproduce the observations, which favors asymmetric mass loss with a more pronounced leading tidal tail, possibly also explaining observational evidence for additional absorption stationary in the stellar rest frame. A trailing tail is not detectable. From our modeling, we derived estimates of ≥2 × 10¹³ g s^‑1 for the stellar and 5.4 × 10¹² g s^‑1 for the planetary mass loss rate, which is consistent with X-ray and extreme-ultraviolet (XUV) driven mass loss in WASP-121 b.

We present a novel way of probing non-gravitational dark matter interactions: dark astronomy, which leverages the dark radiation emitted by dissipative dark sectors. If the mediator of the dark matter self interactions is a dark photon with a small mass that kinetically mixes with the visible photon, the dark radiation flux becomes accessible to underground experiments. We argue that the emission may be dominantly longitudinally polarized, thereby enhancing the sensitivity of direct detection experiments such as XENON and SENSEI to this signal. We introduce a new detection mechanism based on resonant dark-photon-to-photon conversion at the surface of conducting materials, which offers unique directional sensitivity to dark radiation. This mechanism facilitates the development of experiments that combine dark matter detection techniques with methods of traditional astronomy, opening the possibility to map dark radiation sources within our galaxy.

The impact of the dynamical state of gas-rich satellite galaxies at the early moments of their infall into their host systems and the relation to their quenching process are not completely understood at the low-mass regime. Two such nearby systems are the infalling Milky Way (MW) dwarfs Leo T and Phoenix located near the MW virial radius at 414 kpc (1.4R_vir), both of which present intriguing offsets between their gaseous and stellar distributions. Here we present hydrodynamic simulations with RAMSES to reproduce the observed dynamics of Leo T: its 80 pc stellar-HI offset and the 35 pc offset between its older (≳5 Gyr) and younger (∼200 ‑ 1000 Myr) stellar population. We considered internal and environmental properties such as stellar winds, two HI components, cored and cuspy dark matter profiles, and different satellite orbits considering the MW circumgalactic medium. We find that the models that best match the observed morphology of the gas and stars include mild stellar winds that interact with the HI generating the observed offset, and dark matter profiles with extended cores. The latter allow long oscillations of the off-centred younger stellar component, due to long mixing timescales (≳200 Myr), and the slow precession of near-closed orbits in the cored potentials; instead, cuspy and compact cored dark matter models result in the rapid mixing of the material (≲200 Myr). These models predict that non-equilibrium substructures, such as spatial and kinematic offsets, are likely to persist in cored low-mass dwarfs and to remain detectable on long timescales in systems with recent star formation.

We construct the equation of state of hypernuclear matter and study the structure of neutron stars employing a chiral hyperon-nucleon interaction of the Jülich--Bonn group tuned to femtoscopic $\Lambda p$ data of the ALICE collaboration, and $\Lambda\Lambda$ and $\Xi$N interactions determined from Lattice QCD calculations by the HAL QCD collaboration that reproduce the femtoscopic $\Lambda\Lambda$ and $\Xi^-p$ data. We employ the ab-initio microscopic Brueckner--Hartree--Fock theory extended to the strange baryon sector. A special focus is put on the uncertainties of the hyperon interactions and how they are effectively propagated to the composition, equation of state, and mass-radius relation of neutron stars. To such end, we consider the uncertainty due to the experimental error of the femtoscopic $\Lambda p$ data used to fix the chiral hyperon-nucleon interaction and the theoretical uncertainty, estimated from the residual cut-off dependence of this interaction. We find that the final maximum mass of a neutron star with hyperons is in the range $1.3-1.4$ $M_\odot$, in agreement with previous works. The hyperon puzzle, therefore, remains still an open issue if only two-body hyperon-nucleon and hyperon-hyperon interactions are considered.

We critically reconsider the argument based on 't Hooft anomaly matching that aims at proving chiral symmetry breaking in confining four-dimensional quantum chromodynamics-like theories with <inline-formula><mml:math display="inline"><mml:msub><mml:mi>N</mml:mi><mml:mi>c</mml:mi></mml:msub><mml:mo>></mml:mo><mml:mn>2</mml:mn></mml:math></inline-formula> colors and <inline-formula><mml:math display="inline"><mml:msub><mml:mi>N</mml:mi><mml:mi>f</mml:mi></mml:msub></mml:math></inline-formula> flavors. The main line of reasoning relies on a property of the solutions of the anomaly matching and persistent mass equations called <inline-formula><mml:math display="inline"><mml:msub><mml:mi>N</mml:mi><mml:mi>f</mml:mi></mml:msub></mml:math></inline-formula>-independence. In previous works, the validity of <inline-formula><mml:math display="inline"><mml:msub><mml:mi>N</mml:mi><mml:mi>f</mml:mi></mml:msub></mml:math></inline-formula>-independence was assumed based on qualitative arguments, but it was never proven rigorously. We provide a detailed proof and clarify under which (dynamical) conditions it holds. Our results are valid for a generic spectrum of massless composite fermions including baryons and exotics.

We carried out long-term monitoring of the LIGO/Virgo/KAGRA binary black hole (BBH) merger candidate S230922g in search of electromagnetic emission from the interaction of the merger remnant with an embedding active galactic nuclei (AGN) accretion disk. Using a dataset primarily composed of wide-field imaging from the Dark Energy Camera and supplemented by additional photometric and spectroscopic resources, we searched <inline-formula><mml:math display="inline"><mml:mo>∼</mml:mo><mml:mn>70</mml:mn><mml:mo>%</mml:mo></mml:math></inline-formula> of the sky area probability for transient phenomena and discovered six counterpart candidates. One especially promising candidate—AT 2023aagj—exhibited temporally varying asymmetric components in spectral broad line regions, a feature potentially indicative of an off-center event such as a BBH merger. This represents the first live search and multiwavelength, photometric, and spectroscopic monitoring of a gravitational wave BBH optical counterpart candidate in the disk of an AGN.

The projected sensitivity of the effective electron neutrino-mass measurement with the KATRIN experiment is below 0.3 eV (90 % CL) after 5 years of data acquisition. The sensitivity is affected by the increased rate of the background electrons from KATRIN's main spectrometer. A special shifted-analysing-plane (SAP) configuration was developed to reduce this background by a factor of two. The complex layout of electromagnetic fields in the SAP configuration requires a robust method of estimating these fields. We present in this paper a dedicated calibration measurement of the fields using conversion electrons of gaseous <inline-formula id="IEq1"><mml:math id="IEq1_Math"><mml:mmultiscripts><mml:mrow></mml:mrow><mml:mrow></mml:mrow><mml:mtext>83m</mml:mtext></mml:mmultiscripts></mml:math></inline-formula>Kr, which enables the neutrino-mass measurements in the SAP configuration.

We calculate the four-graviton scattering amplitude in Type II superstring theory at one-loop up to seventh order in the low-energy expansion through the recently developed iterated integral formalism of Modular Graph Functions (MGFs). We propose a new assignment of transcendental weight to the numbers that appear in the amplitude, which leads to a violation of uniform transcendentality. Furthermore, the machinery of the novel method allows us to propose a general form of the amplitude, which suggests that the expansion is expressible in terms of single-valued multiple zeta values and logarithmic derivatives of the Riemann zeta function at positive and negative odd integers.

This chapter reviews the three-dimensional structure, age, kinematics, and chemistry of the Milky Way (MW) region within ~2 kpc from its center (hereafter referred to as the 'bulge') from an observational perspective. While not exhaustive in citations, this review provides historical context and discusses the main controversies and limitations in the current consensus. The nuclear bulge region, within $\sim$200 pc from the Galactic center, has been excluded from this review. This very complex region, hosting dense molecular clouds and active star formation, would deserve a dedicated paper.

Accretion-induced collapse (AIC) or merger-induced collapse (MIC) of white dwarfs (WDs) in binary systems is an interesting path to neutron star (NS) and magnetar formation, alternative to stellar core collapse and NS mergers. Such events could add a population of compact remnants in globular clusters, they are expected to produce yet unidentified electromagnetic transients including gamma-ray and radio bursts, and to act as sources of trans-iron elements, neutrinos, and gravitational waves. Here we present the first long-term (>5 s post bounce) hydrodynamical simulations in axi-symmetry (2D), using energy- and velocity-dependent three-flavor neutrino transport based on a two-moment scheme. Our set of six models includes initial WD configurations for different masses, central densities, rotation rates, and angular momentum profiles. Our simulations demonstrate that rotation plays a crucial role for the proto-neutron star (PNS) evolution and ejecta properties. We find early neutron-rich ejecta and an increasingly proton-rich neutrino-driven wind at later times in a non-rotating model, in agreement with electron-capture supernova models. In contrast to that and different from previous results, our rotating models eject proton-rich material initially and increasingly more neutron-rich matter as time advances, because an extended accretion torus forms around the PNS and feeds neutrino-driven bipolar outflows for many seconds. AIC and MIC events are thus potential sites of r-process element production, which may imply constraints on their occurrence rates. Finally, our simulations neglect the effects of triaxial deformation and magnetic fields, serving as a temporary benchmark for more comprehensive future studies.

Chemical clocks based on [s-process elements/alpha-elements] ratios are widely used to estimate ages of Galactic stellar populations. However, the [s/alpha] vs. age relations are not universal, varying with metallicity, location in the Galactic disc, and specific s-process elements. Current Galactic chemical evolution models struggle to reproduce the observed [s/alpha] increase at young ages. We provide chemical evolution models for the Milky Way disc to identify the conditions required to reproduce the observed [s/H], [s/Fe], and [s/alpha] vs. age relations. We adopt a multi-zone chemical evolution model including state-of-the-art nucleosynthesis prescriptions for neutron-capture elements (AGB stars, rotating massive stars, neutron star mergers, magneto-driven supernovae). We explore variations in gas infall, AGB yield dependencies on progenitor stars, and rotational velocity distributions for massive stars. Results are compared with open cluster data from the Gaia-ESO survey. A three-infall scenario for disc formation captures the rise of [s/alpha] with age in the outer regions but fails in the inner ones, especially for second s-process peak elements. Ba production in the last 3 Gyr of chemical evolution would need to increase by half to match observations. S-process contributions from low-mass AGB stars improve predictions but require increases not supported by nucleosynthesis calculations, even with potential i-process contribution. Variations in the metallicity dependence of AGB yields show inconsistent effects across elements. Distributions of massive star rotational velocities fail to improve results due to balanced effects on elements. We confirm that there is no single relationship [s/alpha] vs. age, but that it varies along the MW disc. Current prescriptions for neutron-capture element yields cannot fully capture the complexity of evolution, particularly in the inner disc.

Superclusters are the most massive structures in the universe. To what degree they are actually bound against an accelerating expansion of the background is of significant cosmological and astrophysical interest. In this study, we introduce a cross matched set of superclusters from the SLOW constrained simulations of the local (z<0.05) universe. Identifying the superclusters provides estimates on the efficacy of the constraints in reproducing the local large-scale structure accurately. The simulated counterparts can help identifying possible future observational targets containing interesting features such as bridges between pre-merging and merging galaxy clusters and collapsing filaments and provide comparisons for current observations. By determining the collapse volumes for the superclusters we further elucidate the dynamics of cluster-cluster interactions in those regions. Using catalogs of local superclusters and the most massive simulated clusters, we search for counterparts of supercluster members of six regions. We evaluate the significance of these detections by comparing their geometries to supercluster regions in random simulations. We then run an N-body version of the simulation into the far future and determine which of the member clusters are gravitationally bound to the host superclusters. Furthermore we compute masses and density contrasts for the collapse regions. We demonstrate the SLOW simulation of the local universe to accurately reproduce local supercluster regions in mass of their members and three-dimensional geometrical arrangement. We furthermore find the bound regions of the local superclusters consistent in size and density contrast with previous theoretical studies. This will allow to connect future numerical zoom-in studies of the clusters to the large scale environments and specifically the supercluster environments these local galaxy clusters evolve in.

We update the Standard Model (SM) predictions for the lifetimes of the $B^+$, $B_d$ and $B_s$ mesons within the heavy quark expansion (HQE), including the recently determined NNLO-QCD corrections to non-leptonic decays of the free $b$-quark. In addition, we update the HQE predictions for the lifetime ratios $\tau (B^+)/\tau (B_d)$ and $\tau (B_s)/\tau (B_d)$, and provide new results for the semileptonic branching fractions of the three mesons entirely within the HQE. We obtain a considerable improvement of the theoretical uncertainties, mostly due to the reduction of the renormalisation scale dependence when going from LO to NNLO, and for all the observables considered, we find good agreement, within uncertainties, between the HQE predictions and the corresponding experimental data. Our results read, respectively, $\Gamma (B^+) = 0.587^{+0.025}_{-0.035}~{\rm ps}^{-1}$, $\Gamma (B_d) = 0.636^{+0.028}_{-0.037}~{\rm ps}^{-1}$, $\Gamma (B_s) = 0.628^{+0.027}_{-0.035}~{\rm ps}^{-1}$, for the total decay widths, $\tau (B^+)/\tau (B_d) = 1.081^{+0.014}_{-0.016}$, $\tau (B_s)/\tau (B_d) = 1.013^{+0.007}_{-0.007}$, for the lifetime ratios, and ${\cal B}_{\rm sl} (B^+) = (11.46^{+0.47}_{-0.32}) \%$, ${\cal B}_{\rm sl} (B_d) = (10.57^{+0.47}_{-0.27}) \%$, ${\cal B}_{\rm sl} (B_s) = (10.52^{+0.50}_{-0.29}) \%$, for the semileptonic branching ratios. Finally, we also provide an outlook for further improvements of the HQE determinations of the $B$-meson decay widths and of their ratios.

We construct defects describing the transition between different phases of gauged linear sigma models with higher rank abelian gauge groups, as well as defects embedding these phases into the GLSMs. Our construction refers entirely to the sector protected by B-type supersymmetry, decoupling the gauge sector. It relies on an abstract characterization of such transition defects and does not involve an actual perturbative analysis. It turns out that the choices that are required to characterize consistent transition defects match with the homotopy classes of paths between different phases. Our method applies to non-anomalous as well as anomalous GLSMs, and we illustrate both cases with examples. This includes the GLSM associated to the resolution of the $A_N$ singularity and one describing the entire parameter space of $N = 2$ minimal models, in particular, the relevant flows between them. Via fusion with boundary conditions, the defects we construct yield functors describing the transport of D-branes on parameter space. We find that our results match with known results on D-brane transport.

Strongly lensed Type Ia supernovae (LSNe Ia) are a promising probe with which to measure the Hubble constant (H₀) directly. To use LSNe Ia for cosmography, a time-delay measurement between multiple images, a lens-mass model, and a mass reconstruction along the line of sight are required. In this work, we present the machine-learning network LSTM-FCNN, which is a combination of a long short-term memory network (LSTM) and a fully connected neural network (FCNN). The LSTM-FCNN is designed to measure time delays on a sample of LSNe Ia spanning a broad range of properties, which we expect to find with the upcoming Rubin Observatory Legacy Survey of Space and Time (LSST) and for which follow-up observations are planned. With follow-up observations in the i band (cadence of one to three days with a single-epoch 5σ depth of 24.5 mag), we reach a bias-free delay measurement with a precision of around 0.7 days over a large sample of LSNe Ia. The LSTM-FCNN is far more general than previous machine-learning approaches such as the random forest (RF) one, whereby an RF has to be trained for each observational pattern separately, and yet the LSTM-FCNN outperforms the RF by a factor of roughly three. Therefore, the LSTM-FCNN is a very promising approach to achieve robust time delays in LSNe Ia, which is important for a precise and accurate constraint on H₀.

The mass accretion rate of galaxy clusters is a key factor in determining their structure, but a reliable observational tracer has yet to be established. We present a state-of-the-art machine learning model for constraining the mass accretion rate of galaxy clusters from only X-ray and thermal Sunyaev-Zeldovich observations. Using idealized mock observations of galaxy clusters from the MillenniumTNG simulation, we train a machine learning model to estimate the mass accretion rate. The model constrains 68% of the mass accretion rates of the clusters in our dataset to within 33% of the true value without significant bias, a ~58% reduction in the scatter over existing constraints. We demonstrate that the model uses information from both radial surface brightness density profiles and asymmetries.

Submillimeter single-dish telescopes offer two key advantages compared to interferometers: they can efficiently map larger portions of the sky and recover larger spatial scales. Nonetheless, fluctuations in the atmosphere limit the accurate retrieval of signals from astronomical sources. Therefore, we introduce a user-friendly simulator named maria to optimize scanning strategies and instrument designs to efficiently reduce atmospheric noise and filtering effects. We further use this tool to produce synthetic time streams and maps from hydrodynamical simulations, enabling a fair comparison between theory and reality. maria has implemented a suite of telescope and instrument designs intended to mimic current and future facilities. To generate synthetic time-ordered data, each mock observatory scans through the atmosphere in a configurable pattern over the celestial object. We generate evolving and location-and-time-specific weather for each of the fiducial sites using a combination of satellite and ground-based measurements. While maria is a generic virtual telescope, this study specifically focuses on mimicking broadband bolometers observing at 100 GHz. To validate our virtual telescope, we compare the mock time streams with real MUSTANG-2 observations and find that they are quantitatively similar by conducting a k-sample Anderson-Darling test resulting in p<0.001. Subsequently, we image the time-ordered data to create noise maps and mock observations of clusters of galaxies for both MUSTANG-2 and an instrument concept for the 50m Atacama Large Aperture Submillimeter Telescope (AtLAST). Furthermore, using maria, we find that a 50m dish provides the highest levels of correlation of atmospheric signals across adjacent detectors compared to smaller apertures (e.g., 42-cm and 6-m survey experiments), facilitating removal of atmospheric signal on large scales.

Nonlinearities in King plots (KP) of isotope shifts (IS) can reveal the existence of beyond-Standard-Model (BSM) interactions that couple electrons and neutrons. However, it is crucial to distinguish higher-order Standard Model (SM) effects from BSM physics. We measure the IS of the transitions ${{}^{3}P_{0}~\rightarrow~{}^{3}P_{1}}$ in $\mathrm{Ca}^{14+}$ and ${{}^{2}S_{1/2} \rightarrow {}^{2}D_{5/2}}$ in $\mathrm{Ca}^{+}$ with sub-Hz precision as well as the nuclear mass ratios with relative uncertainties below $4\times10^{-11}$ for the five stable, even isotopes of calcium (${}^{40,42,44,46,48}\mathrm{Ca}$). Combined, these measurements yield a calcium KP nonlinearity with a significance of $\sim 900 \sigma$. Precision calculations show that the nonlinearity cannot be fully accounted for by the expected largest higher-order SM effect, the second-order mass shift, and identify the little-studied nuclear polarization as the only remaining SM contribution that may be large enough to explain it. Despite the observed nonlinearity, we improve existing KP-based constraints on a hypothetical Yukawa interaction for most of the new boson masses between $10~\mathrm{eV/c^2}$ and $10^7~\mathrm{eV/c^2}$.

We study the femtoscopic correlation functions of meson-baryon pairs in the strangeness $S=-1$ sector, employing unitarized s-wave scattering amplitudes derived from the chiral Lagrangian up to next-to-leading order. For the first time, we deliver predictions on the $\pi^-\Lambda$ and $K^+\Xi^-$ correlation functions which are feasible to be measured at the Large Hadron Collider. We also demonstrate that the employed model is perfectly capable of reproducing the $K^-p$ correlation function data measured by the same collaboration, without the need to modify the coupling strength to the $\bar{K}^0n$ channel, as has been recently suggested. In all cases, the effects of the source size on the correlation are tested. In addition, we present detailed analysis of the different coupled-channel contributions, together with the quantification of the relative relevance of the different terms in the interaction.

Aims. Detecting diffuse synchrotron emission from the cosmic web is still a challenge for current radio telescopes. We aim to make predictions about the detectability of cosmic web filaments from simulations. Methods. We present the first cosmological magnetohydrodynamic simulation of a 500 h^‑1 c Mpc volume with an on-the-fly spectral cosmic ray (CR) model. This allows us to follow the evolution of populations of CR electrons and protons within every resolution element of the simulation. We modeled CR injection at shocks, while accounting for adiabatic changes to the CR population and high-energy-loss processes of electrons. The synchrotron emission was then calculated from the aged electron population, using the simulated magnetic field, as well as different models for the origin and amplification of magnetic fields. We used constrained initial conditions, which closely resemble the local Universe, and compared the results of the cosmological volume to a zoom-in simulation of the Coma cluster, to study the impact of resolution and turbulent reacceleration of CRs on the results. Results. We find a consistent injection of CRs at accretion shocks onto cosmic web filaments and galaxy clusters. This leads to diffuse emission from filaments of the order S_ν ≈ 0.1 μJy beam^‑1 for a potential LOFAR observation at 144 MHz, when assuming the most optimistic magnetic field model. The flux can be increased by up to two orders of magnitude for different choices of CR injection parameters. This can bring the flux within a factor of ten of the current limits for direct detection. We find a spectral index of the simulated synchrotron emission from filaments of α ≈ ‑1.0 to –1.5 in the LOFAR band.

We present GalSBI, a phenomenological model of the galaxy population for cosmological applications using simulation-based inference. The model is based on analytical parametrizations of galaxy luminosity functions, morphologies and spectral energy distributions. Model constraints are derived through iterative Approximate Bayesian Computation, by comparing Hyper Suprime-Cam deep field images with simulations which include a forward model of instrumental, observational and source extraction effects. We developed an emulator trained on image simulations using a normalizing flow. We use it to accelerate the inference by predicting detection probabilities, including blending effects and photometric properties of each object, while accounting for background and PSF variations. This enables robustness tests for all elements of the forward model and the inference. The model demonstrates excellent performance when comparing photometric properties from simulations with observed imaging data for key parameters such as magnitudes, colors and sizes. The redshift distribution of simulated galaxies agrees well with high-precision photometric redshifts in the COSMOS field within $1.5\sigma$ for all magnitude cuts. Additionally, we demonstrate how GalSBI's redshifts can be utilized for splitting galaxy catalogs into tomographic bins, highlighting its potential for current and upcoming surveys. GalSBI is fully open-source, with the accompanying Python package, $\texttt{galsbi}$, offering an easy interface to quickly generate realistic, survey-independent galaxy catalogs.

Context. Computing reliable photometric redshifts (photo-z) for active galactic nuclei (AGN) is a challenging task, primarily due to the complex interplay between the unresolved relative emissions associated with the supermassive black hole and its host galaxy. Spectral energy distribution (SED) fitting methods, while effective for galaxies and AGN in pencil-beam surveys, face limitations in wide or all-sky surveys with fewer bands available, lacking the ability to accurately capture the AGN contribution to the SED, hindering reliable redshift estimation. This limitation is affecting the many tens of millions of AGN detected in existing datasets, such as those AGN clearly singled out and identified by SRG/eROSITA. Aims. Our goal is to enhance photometric redshift performance for AGN in all-sky surveys while simultaneously simplifying the approach by avoiding the need to merge multiple data sets. Instead, we employ readily available data products from the 10th Data Release of the Imaging Legacy Survey for the Dark Energy Spectroscopic Instrument, which covers >20 000 deg² of extragalactic sky with deep imaging and catalog-based photometry in the ɡriɀW1-W4 bands. We fully utilize the spatial flux distribution in the vicinity of each source to produce reliable photo-z. Methods. We introduce PICZL, a machine-learning algorithm leveraging an ensemble of convolutional neural networks. Utilizing a cross-channel approach, the algorithm integrates distinct SED features from images with those obtained from catalog-level data. Full probability distributions are achieved via the integration of Gaussian mixture models. Results. On a validation sample of 8098 AGN, PICZL achieves an accuracy σ_NMAD of 4.5% with an outlier fraction η of 5.6%. These results significantly outperform previous attempts to compute accurate photo-z for AGN using machine learning. We highlight that the model's performance depends on many variables, predominantly the depth of the data and associated photometric error. A thorough evaluation of these dependencies is presented in the paper. Conclusions. Our streamlined methodology maintains consistent performance across the entire survey area, when accounting for differing data quality. The same approach can be adopted for future deep photometric surveys such as LSST and Euclid, showcasing its potential for wide-scale realization. With this paper, we release updated photo-z (including errors) for the XMM-SERVS W-CDF-S, ELAIS-S1 and LSS fields.

The Standard Model extended by a real scalar singlet $S$ with an approximate $\mathbb{Z}_2$ symmetry offers a minimal framework for realizing electroweak baryogenesis (EWBG) during a first-order electroweak phase transition. In this work, we explore a novel mechanism where spontaneous $\mathbb{Z}_2$ breaking enables EWBG via domain walls separating two distinct phases of the $S$ field. These domain walls feature restored (or weakly broken) EW symmetry in their cores and sweep through space, generating the baryon asymmetry below the temperature of EW symmetry breaking. We identify the key conditions for the existence of EW-symmetric domain wall cores and analyze the dynamics required for wall propagation over sufficient spatial volumes. Additionally, we outline the CP-violating sources necessary for baryogenesis under different regimes of domain wall evolution. The parameter space accommodating this mechanism spans singlet masses from sub-eV to 15 GeV, accompanied by a non-vanishing mixing with the Higgs boson. Unlike the standard realization of EWBG in the minimal singlet-extended SM, which is notoriously difficult to test, our scenario can be probed by a wide range of existing and upcoming experiments, including fifth force searches, rare meson decays, and EDM measurements.

Our current understanding is that intermediate- to high-mass stars form in a way similar to low-mass stars, that is, through disk accretion. However, the physical conditions that play a role in disk formation, evolution, and the possibility of (sub)stellar companion formation, are significantly different. We search for the mm counterparts of four intermediate- to high-mass (4-10 Solar mass) young stellar objects (YSOs) in the giant Hii region M17 at a distance of 1.7 kpc. These objects expose their photospheric spectrum such that their location on the pre-main-sequence (PMS) is well established. They have a circumstellar disk that is likely remnant of the formation process. With ALMA we have detected, for the first time, these four YSOs in M17, in Band 6 and 7, as well as four other serendipitous objects. Besides the flux measurements, the source size and spectral index provide important constraints on the physical mechanism(s) producing the observed emission. We apply different models to estimate the dust and gas mass contained in the disks. All our detections are spatially unresolved, constraining the source size to <120 au, and have a spectral index in the range 0.5-2.7. The derived (upper limits on the) disk dust masses are on the order of a few Earth masses and estimations of the upper limits on the gas mass vary between $10^{-5}$ and $10^{-3}$ Solar mass. In two objects (B331 and B268) free-free emission indicates the presence of ionized material around the star. The four serendipitous detections are likely (low-mass) YSOs. We compare the derived disk masses of our M17 targets to those obtained for YSOs in low-mass star-forming regions (SFRs) and Herbig stars, as a function of stellar mass, age, luminosity, and outer disk radius. The M17 sample, though small, is both the most massive and the youngest sample, yet has the lowest mean disk mass.

Context. Increasing evidence shows that warped disks are common, challenging the methods used to model their velocity fields. Molecular line emission of these disks is characterized by a twisted pattern, similar to the signal from radial flows, complicating the study of warped disk kinematics. Previous attempts to model these features have encountered difficulties in distinguishing between the underlying kinematics of different disks. Aims. This study aims to advance gas kinematics modeling capabilities by extending the Extracting Disk Dynamics (eddy) package to include warped geometries and radial flows. We assess the performance of eddy in recovering input parameters for scenarios involving warps, radial flows, and combinations of the two. Additionally, we provide a basis to break the visual degeneracy between warped disks and radial flow, establishing a criterion to distinguish them. Methods. We extended the eddy package to handle warped geometries by including a parametric prescription of a warped disk and a ray-casting algorithm to account for the surface self-obscuration arising from the 3D to 2D projection. The effectiveness of the tool was tested using the radiative transfer code RADMC3D, generating synthetic models for disks with radial flows, warped disks, and warped disks with radial flows. Results. We demonstrate the efficacy of our tool in accurately recovering the geometrical parameters of systems, particularly in data with sufficient angular resolution. Importantly, we observe minimal impact from thermal noise levels typical in Atacama Large Millimeter/submillimeter Array (ALMA) observations. Furthermore, our findings reveal that fitting an incorrect model type produces characteristic residual signatures, which serve as kinematic criteria for disk classification. Conclusions. Characterizing gas kinematics requires careful consideration of twisted motions. While our model provides insights into disk geometries, caution is needed when interpreting parameters in regions with complex kinematics or low-resolution data. Future ALMA baseline observations should help clarify warped disk kinematics.

We present a detailed survey of electric, magnetic, and quadrupole form factors of light and heavy spin-1 vector mesons. It complements our analogous analysis of the electromagnetic form factors of pseudoscalar and scalar mesons reported earlier. Our formalism is based upon the Schwinger-Dyson equations treatment of a vector <inline-formula><mml:math display="inline"><mml:mo>×</mml:mo></mml:math></inline-formula> vector contact interaction and the Bethe-Salpeter equation description of relativistic two-body bound states. We compute the form factors, associated moments, and charge radii, comparing these quantities to earlier theoretical studies and experimental results if and when possible. We also investigate the quark-mass dependence of the charge radii and find the anticipated hierarchy such that it decreases with increasing dressed quark masses. In addition, our analysis shows that the magnetic moment is independent of the mass of the light and heavy mesons. Our results agree with most measurements reported earlier, finding a negative quadrupole moment, implying the charge distribution is oblate.

Real-world systems are shaped by both their complex internal interactions and the changes in their noisy environments. In this work, we study how a shared active bath affects the statistical dependencies between two interacting Brownian particles by evaluating their mutual information. We decompose the mutual information into three terms: information stemming from the internal interactions between the particles; information induced by the shared bath, which encodes environmental changes; a term describing information interference that quantifies how the combined presence of both internal interactions and environment either masks (destructive interference) or boosts (constructive interference) information. By studying exactly the case of linear interactions, we find that the sign of information interference depends solely on that of the internal coupling. However, when internal interactions are described by a nonlinear activation function, we show that both constructive and destructive interference appear depending on the interplay between the timescale of the active environment, the internal interactions, and the environmental coupling. Finally, we show that our results generalize to hierarchical systems where asymmetric couplings to the environment mimic the scenario where the active bath is only partially accessible to one particle. This setting allows us to quantify how this asymmetry drives information interference. Our work underscores how information and functional relationships in complex multiscale systems are fundamentally shaped by the environmental context.

Studying the orbital motion of stars around Sagittarius A* in the Galactic center provides a unique opportunity to probe the gravitational potential near the supermassive black hole at the heart of our Galaxy. Interferometric data obtained with the GRAVITY instrument at the Very Large Telescope Interferometer (VLTI) since 2016 has allowed us to achieve unprecedented precision in tracking the orbits of these stars. GRAVITY data have been key to detecting the in-plane, prograde Schwarzschild precession of the orbit of the star S2 that is predicted by general relativity. By combining astrometric and spectroscopic data from multiple stars, including S2, S29, S38, and S55 – for which we have data around their time of pericenter passage with GRAVITY – we can now strengthen the significance of this detection to an approximately 10σ confidence level. The prograde precession of S2's orbit provides valuable insights into the potential presence of an extended mass distribution surrounding Sagittarius A*, which could consist of a dynamically relaxed stellar cusp comprising old stars and stellar remnants, along with a possible dark matter spike. Our analysis, based on two plausible density profiles – a power-law and a Plummer profile – constrains the enclosed mass within the orbit of S2 to be consistent with zero, establishing an upper limit of approximately 1200 M_⊙ with a 1σ confidence level. This significantly improves our constraints on the mass distribution in the Galactic center. Our upper limit is very close to the expected value from numerical simulations for a stellar cusp in the Galactic center, leaving little room for a significant enhancement of dark matter density near Sagittarius A*.

We present a spectroscopic analysis of MACS J0138$-$2155, at $z=0.336$, the first galaxy cluster hosting two strongly-lensed supernovae (SNe), Requiem and Encore, providing us with a chance to obtain a reliable $H_0$ measurement from the time delays between the multiple images. We take advantage of new data from the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope, covering a central $1 \rm \, arcmin^2$ of the lensing cluster, for a total depth of 3.7 hours, including 2.9 hours recently obtained by our Target of Opportunity programme. Our new spectroscopic catalogue contains reliable redshifts for 107 objects, including 50 galaxy cluster members with secure redshift values in the range $0.324 < z < 0.349$, and 13 lensed multiple images from four background sources between $0.767\leq z \leq 3.420$, including four images of the host galaxy of the two SNe. We exploit the MUSE data to study the stellar kinematics of 14 bright cluster members and two background galaxies, obtaining reliable measurements of their line-of-sight velocity dispersion. Finally, we combine these results with measurements of the total magnitude of the cluster members in the Hubble Space Telescope F160W band to calibrate the Faber-Jackson relation between luminosity and stellar velocity dispersion ($L \propto \sigma^{1/\alpha}$) for the early-type cluster member galaxies, measuring a slope $\alpha=0.25^{+0.05}_{-0.05}$. A pure and complete sample of cluster member galaxies and a reliable characterisation of their total mass structure are key to building accurate total mass maps of the cluster, mitigating the impact of parametric degeneracies, which is necessary for inferring the value of $H_0$ from the measured time delays between the lensed images of the two SNe.

A new and detailed measurement of the cross section for hard exclusive neutral-pion muoproduction on the proton was performed in a wide kinematic region, with the photon virtuality $Q^2$ ranging from 1 to 8 (GeV/$c$)$^{\rm\, 2}$ and the Bjorken variable $x_{\rm Bj}$ ranging from 0.02 to 0.45. The data were collected at COMPASS at CERN using 160 GeV/$c$ longitudinally polarised $\mu^+$ and $\mu^-$ beams scattering off a 2.5 m long liquid hydrogen target. From the average of the measured $\mu^+$ and $\mu^-$ cross sections, the virtual-photon--proton cross section is determined as a function of the squared four-momentum transfer between the initial and final state proton in the range 0.08 (GeV/$c$)$^{\rm\, 2}$$< |t| <$ 0.64 (GeV/$c$)$^{\rm\, 2}$. From its angular distribution, the combined contribution of transversely and longitudinally polarised photons are determined, as well as transverse--transverse and longitudinal--transverse interference contributions. They are studied as functions of four-momentum transfer $|t|$, photon virtuality $Q^2$ and virtual-photon energy $\nu$. The longitudinal--transverse interference contribution is found to be compatible with zero. The significant transverse--transverse interference contribution reveals the existence of a dominant contribution by transversely polarized photons. This provides clear experimental evidence for the chiral-odd GPD $\overline{E}_T$. In addition, the existence of a non-negligible contribution of longitudinally polarized photons is suggested by the $|t|$-dependence of the cross section at $x_{\rm Bj} < $ 0.1 . Altogether, these results provide valuable input for future modelling of GPDs and thus of cross sections for exclusive pseudo-scalar meson production. Furthermore, they can be expected to facilitate the study of next-to-leading order corrections and higher-twist contributions.

The Intra Cluster Medium (ICM) of Galaxy Clusters (GCs) is a highly dynamic environment. It is shaped by mergers and bulk motions on large scales. Small scales are dominated by turbulence, connected to large scales via a turbulent cascade. Both observations and simulations predict this turbulence to be subsonic. This poses numerical challenges for calculating the turbulent cascade and requires careful numerical treatment of hydrodynamics.

Many different numerical methods have been developed and applied to this specific problem. They can be divided according to their discretization approach into grid-based volume-discretization methods, such as stationary and moving meshes, and mass-discretization methods such as Smoothed Particle Hydrodynamics (SPH). More recently, Meshless Finite Mass (MFM) has been developed. The gas is discretized by mass, but fluxes between neighbors are calculated, thus combining the advantages of SPH with grid-based methods.

In this work, we present a new implementation of MFM in the cosmological simulation code OpenGadget3. It is based on the implementation in the Gandalf code but has been extended to allow for cosmological applications. One main goal is the application to subsonic turbulence in the ICM of GCs and a detailed and fair comparison with other hydrodynamical methods. [...]

The existence of light QCD axions, whose mass depends on an additional free parameter, can lead to a new ground state of matter, where the sourced axion field reduces the nucleon effective mass. The presence of the axion field has structural consequences, in particular, it results in a thinner (or even prevents its existence) heat-blanketing envelope, significantly altering the cooling patterns of neutron stars. We exploit the anomalous cooling behavior to constrain previously uncharted regions of the axion parameter space by comparing model predictions with existing data from isolated neutron stars. Notably, this analysis does not require the light QCD axion to be the dark matter candidate.

We perform an all-order analysis of double-logarithmic corrections to the so-called soft-overlap contribution to heavy-to-light transition form factors at large hadronic recoil. Specifically, we study $B_c \to \eta_c$ transitions within a perturbative non-relativistic framework, treating both the bottom and charm quarks as heavy with the hierarchy $m_b \gg m_c \gg\Lambda_{\rm QCD}$. Our diagrammatic analysis shows that double-logarithmic corrections arise from two distinct sources: Exponentiated soft-gluon effects described by standard Sudakov factors, and rapidity-ordered soft-quark configurations, leading to implicit integral equations, which so far have only been studied in the context of energetic muon-electron backward scattering. We find that the all-order structure of the double logarithms is governed by a novel type of coupled integral equations, which encode the non-trivial interplay between these two effects. Whereas a closed-form solution to these equations is currently unknown, we present useful iteration formulas, and derive the asymptotic behaviour of the soft-overlap form factor for infinitely large recoil energies, showing that the Sudakov suppression is somewhat weakened by the intertwined soft-quark and soft-gluon corrections. In a broader context, our findings shed light onto the physical origin and mathematical structure of endpoint divergences arising from soft-collinear factorization and the related Feynman mechanism for power-suppressed hard exclusive processes.

Rotation matters for the life of a star. It causes a multitude of dynamical phenomena in the stellar interior during a star's evolution, and its effects accumulate until the star dies. All stars rotate at some level, but most of those born with a mass higher than 1.3 times the mass of the Sun rotate rapidly during more than 90% of their nuclear lifetime. Internal rotation guides the angular momentum and chemical element transport throughout the stellar interior. These transport processes change over time as the star evolves. The cumulative effects of stellar rotation and its induced transport processes determine the helium content of the core by the time it exhausts its hydrogen isotopes. The amount of helium at that stage also guides the heavy element yields by the end of the star's life. A proper theory of stellar evolution and any realistic models for the chemical enrichment of galaxies must be based on observational calibrations of stellar rotation and of the induced transport processes. In the last few years, asteroseismology offers such calibrations for single and binary stars. We review the current status of asteroseismic modelling of rotating stars for different stellar mass regimes in an accessible way for the non-expert. While doing so, we describe exciting opportunities sparked by asteroseismology for various domains in astrophysics, touching upon topics such as exoplanetary science, galactic structure and evolution, and gravitational wave physics to mention just a few. Along the way we provide ample sneak-previews for future 'industrialised' applications of asteroseismology to slow and rapid rotators from the exploitation of combined Kepler, Transiting Exoplanet Survey Satellite (TESS), PLAnetary Transits and Oscillations of stars (PLATO), Gaia, and ground-based spectroscopic and multi-colour photometric surveys. We end the review with a list of takeaway messages and achievements of asteroseismology that are of relevance for many fields of astrophysics.

Estimates of seismic wave speeds in the Earth (seismic velocity models) are key input parameters to earthquake simulations for ground motion prediction. Owing to the non-uniqueness of the seismic inverse problem, typically many velocity models exist for any given region. The arbitrary choice of which velocity model to use in earthquake simulations impacts ground motion predictions. However, current hazard analysis methods do not account for this source of uncertainty. We present a proof-of-concept ground motion prediction workflow for incorporating uncertainties arising from inconsistencies between existing seismic velocity models. Our analysis is based on the probabilistic fusion of overlapping seismic velocity models using scalable Gaussian process (GP) regression. Specifically, we fit a GP to two synthetic 1-D velocity profiles simultaneously, and show that the predictive uncertainty accounts for the differences between the models. We subsequently draw velocity model samples from the predictive distribution and estimate peak ground displacement using acoustic wave propagation through the velocity models. The resulting distribution of possible ground motion amplitudes is much wider than would be predicted by simulating shaking using only the two input velocity models. This proof-of-concept illustrates the importance of probabilistic methods for physics-based seismic hazard analysis.

We derive a cutting rule for equal-time in-in correlators including cosmological correlators based on Keldysh r/a basis, which decomposes diagrams into fully retarded functions and cut-propagators consisting of Wightman functions. Our derivation relies only on basic assumptions such as unitarity, locality, and the causal structure of the in-in formalism, and therefore holds for theories with arbitrary particle contents and local interactions at any loop order. As an application, we show that non-local cosmological collider signals arise solely from cut-propagators under the assumption of microcausality. Since the cut-propagators do not contain (anti-)time-ordering theta functions, the conformal time integrals are factorized, simplifying practical calculations.

In modern collider experiments, the quest to explore fundamental interactions between elementary particles has reached unparalleled levels of precision. Signatures from particle physics detectors are low-level objects (such as energy depositions or tracks) encoding the physics of collisions (the final state particles of hard scattering interactions). The complete simulation of them in a detector is a computational and storage-intensive task. To address this computational bottleneck in particle physics, alternative approaches have been developed, introducing additional assumptions and trade off accuracy for speed. The field has seen a surge in interest in surrogate modeling the detector simulation, fueled by the advancements in deep generative models. These models aim to generate responses that are statistically identical to the observed data. In this paper, we conduct a comprehensive and exhaustive taxonomic review of the existing literature on the simulation of detector signatures from both methodological and application-wise perspectives. Initially, we formulate the problem of detector signature simulation and discuss its different variations that can be unified. Next, we classify the state-of-the-art methods into five distinct categories based on their underlying model architectures, summarizing their respective generation strategies. Finally, we shed light on the challenges and opportunities that lie ahead in detector signature simulation, setting the stage for future research and development.

Astrophysical turbulent flows display an intrinsically multi-scale nature, making their numerical simulation and the subsequent analyses of simulated data a complex problem. In particular, two fundamental steps in the study of turbulent velocity fields are the Helmholtz-Hodge decomposition (compressive+solenoidal; HHD) and the Reynolds decomposition (bulk+turbulent; RD). These problems are relatively simple to perform numerically for uniformly-sampled data, such as the one emerging from Eulerian, fix-grid simulations; but their computation is remarkably more complex in the case of non-uniformly sampled data, such as the one stemming from particle-based or meshless simulations. In this paper, we describe, implement and test vortex-p, a publicly available tool evolved from the vortex code, to perform both these decompositions upon the velocity fields of particle-based simulations, either from smoothed particle hydrodynamics (SPH), moving-mesh or meshless codes. The algorithm relies on the creation of an ad-hoc adaptive mesh refinement (AMR) set of grids, on which the input velocity field is represented. HHD is then addressed by means of elliptic solvers, while for the RD we adapt an iterative, multi-scale filter. We perform a series of idealised tests to assess the accuracy, convergence and scaling of the code. Finally, we present some applications of the code to various SPH and meshless finite-mass (MFM) simulations of galaxy clusters performed with OpenGadget3, with different resolutions and physics, to showcase the capabilities of the code.

We present the Astrophysical Multimessenger Modeling (AM ³ ) software. AM ³ is a documented open-source software (source code at gitlab.desy.de/am3/am3; user guide and documentation at am3.readthedocs.io/en/latest/) that efficiently solves the coupled integro-differential equations describing the temporal evolution of the spectral densities of particles interacting in astrophysical environments, including photons, electrons, positrons, protons, neutrons, pions, muons, and neutrinos. The software has been extensively used to simulate the multiwavelength and neutrino emission from active galactic nuclei (including blazars), gamma-ray bursts, and tidal disruption events. The simulations include all relevant nonthermal processes, namely synchrotron emission, inverse Compton scattering, photon–photon annihilation, proton–proton and proton–photon pion production, and photo-pair production. The software self-consistently calculates the full cascade of primary and secondary particles, including nonlinear feedback processes and predictions in the time domain. It also allows the user to track separately the particle densities produced by means of each distinct interaction process, including the different hadronic channels. With its efficient hybrid solver combining analytical and numerical techniques, AM ³ combines efficiency and accuracy at a user-adjustable level. We describe the technical details of the numerical framework and present three examples of applications to different astrophysical environments.

We extend the evolution-mapping approach, introduced in the first paper of this series to describe non-linear matter density fluctuations, to statistics of the cosmic velocity field. This framework classifies cosmological parameters into shape parameters, which determine the shape of the linear matter power spectrum, <inline-formula><tex-math id="TM0001" notation="LaTeX">$P_{\rm L}(k, z)$</tex-math></inline-formula>, and evolution parameters, which control its amplitude at any redshift. Evolution-mapping leverages the fact that density fluctuations in cosmologies with identical shape parameters but different evolution parameters exhibit similar non-linear evolutions when expressed as a function of clustering amplitude. We analyse a suite of N-body simulations sharing identical shape parameters but spanning a wide range of evolution parameters. Using a method for estimating the volume-weighted velocity field based on the Voronoi tessellation of simulation particles, we study the non-linear evolution of the velocity divergence power spectrum, <inline-formula><tex-math id="TM0002" notation="LaTeX">$P_{\theta \theta }(k)$</tex-math></inline-formula>, and its cross-power spectrum with the density field, <inline-formula><tex-math id="TM0003" notation="LaTeX">$P_{\delta \theta }(k)$</tex-math></inline-formula>. We demonstrate that the evolution-mapping relation applies accurately to <inline-formula><tex-math id="TM0004" notation="LaTeX">$P_{\theta \theta }(k)$</tex-math></inline-formula> and <inline-formula><tex-math id="TM0005" notation="LaTeX">$P_{\delta \theta }(k)$</tex-math></inline-formula>. While this breaks down in the strongly non-linear regime, deviations can be modelled in terms of differences in the suppression factor, <inline-formula><tex-math id="TM0006" notation="LaTeX">$g(a) = D(a)/a$</tex-math></inline-formula>, similar to those for the density field. Such modelling describes the differences in <inline-formula><tex-math id="TM0007" notation="LaTeX">$P_{\theta \theta }(k)$</tex-math></inline-formula> between models with the same linear clustering amplitude to better than 1 per cent accuracy at all scales and redshifts considered. Evolution-mapping simplifies the description of the cosmological dependence of non-linear density and velocity statistics, streamlining the sampling of large cosmological parameter spaces for cosmological analysis.

Very-metal-poor stars ([Fe/H] < ‑2) are important laboratories for testing stellar models and reconstructing the formation history of our galaxy. Asteroseismology is a powerful tool to probe stellar interiors and measure ages, but few asteroseismic detections are known in very-metal-poor stars and none have allowed detailed modeling of oscillation frequencies. We report the discovery of a low-luminosity Kepler red giant (KIC 8144907) with high signal-to-noise ratio oscillations, [Fe/H] = ‑2.66 ± 0.08 and [α/Fe] = 0.38 ± 0.06, making it by far the most metal-poor star to date for which detailed asteroseismic modeling is possible. By combining the oscillation spectrum from Kepler with high-resolution spectroscopy, we measure an asteroseismic mass and age of 0.79 ± 0.02(ran) ± 0.01(sys) M _⊙ and 12.0 ± 0.6(ran) ± 0.4(sys) Gyr, with remarkable agreement across different codes and input physics, demonstrating that stellar models and asteroseismology are reliable for very-metal-poor stars when individual frequencies are used. The results also provide a direct age anchor for the early formation of the Milky Way, implying that substantial star formation did not commence until redshift z ≈ 3 (if the star formed in situ) or that the Milky Way has undergone merger events for at least ≈12 Gyr (if the star was accreted by a dwarf satellite merger such as Gaia-Enceladus).

The high-precision measurements of exoplanet transit light curves that are now available contain information about the planet properties, their orbital parameters, and stellar limb darkening (LD). Recent 3D magnetohydrodynamical (MHD) simulations of stellar atmospheres have shown that LD depends on the photospheric magnetic field, and hence its precise determination can be used to estimate the field strength. Among existing LD laws, the uses of the simplest ones may lead to biased inferences, whereas the uses of complex laws typically lead to a large degeneracy among the LD parameters. We have developed a novel approach in which we use a complex LD model but with second derivative regularization during the fitting process. Regularization controls the complexity of the model appropriately and reduces the degeneracy among LD parameters, thus resulting in precise inferences. The tests on simulated data suggest that our inferences are not only precise but also accurate. This technique is used to re-analyse 43 transit light curves measured by the NASA Kepler and Transiting Exoplanet Survey Satellite missions. Comparisons of our LD inferences with the corresponding literature values show good agreement, while the precisions of our measurements are better by up to a factor of 2. We find that 1D non-magnetic model atmospheres fail to reproduce the observations while 3D MHD simulations are qualitatively consistent. The LD measurements, together with MHD simulations, confirm that Kepler-17, WASP-18, and KELT-24 have relatively high magnetic fields (<inline-formula><tex-math id="TM0001" notation="LaTeX">$\gt 200$</tex-math></inline-formula> G). This study paves the way for estimating the stellar surface magnetic field using the LD measurements.

Aims. Our goal is twofold. First, to detect new clusters we apply the newest methods for the detection of clustering with the best available wide-field sky surveys in the mid-infrared because they are the least affected by extinction. Second, we address the question of cluster detection's completeness, for now limiting it to the most massive star clusters. Methods. This search is based on the mid-infrared Galactic Legacy Infrared Mid Plane Survey Extraordinaire (GLIMPSE), to minimize the effect of dust extinction. The search Ordering Points To Identify the Clustering Structure (OPTICS) clustering algorithm is applied to identify clusters, after excluding the bluest, presumably foreground sources, to improve the cluster-to-field contrast. The success rate for cluster identification is estimated with a semi-empirical simulation that adds clusters, based on the real objects, to the point source catalog, to be recovered later with the same search algorithm that was used in the search for new cluster candidates. As a first step, this is limited to the most massive star clusters with a total mass of 104 $M_\odot$. Results. Our automated search, combined with inspection of the color-magnitude diagrams and images yielded 659 cluster candidates; 106 of these appear to have been previously identified, suggesting that a large hidden population of star clusters still exists in the inner Milky Way. However, the search for the simulated supermassive clusters achieves a recovery rate of 70 to 95%, depending on the distance and extinction toward them. Conclusions. The new candidates, if confirmed, indicate that the Milky Way still harbors a sizeable population of still unknown clusters. However, they must be objects of modest richness, because our simulation indicates that there is no substantial hidden population of supermassive clusters in the central region of our Galaxy.

Future cosmic microwave background (CMB) experiments are primarily targeting a detection of the primordial $B$-mode polarisation. The faintness of this signal requires exquisite control of systematic effects which may bias the measurements. In this work, we derive requirements on the relative calibration accuracy of the overall polarisation gain ($\Delta g_\nu$) for LiteBIRD experiment, through the application of the blind Needlet Internal Linear Combination (NILC) foreground-cleaning method. We find that minimum variance techniques, as NILC, are less affected by gain calibration uncertainties than a parametric approach, which requires a proper modelling of these instrumental effects. The tightest constraints are obtained for frequency channels where the CMB signal is relatively brighter (166 GHz channel, $\Delta {g}_\nu \approx 0.16 \%$), while, with a parametric approach, the strictest requirements were on foreground-dominated channels. We then propagate gain calibration uncertainties, corresponding to the derived requirements, into all frequency channels simultaneously. We find that the overall impact on the estimated $r$ is lower than the required budget for LiteBIRD by almost a factor $5$. The adopted procedure to derive requirements assumes a simple Galactic model. We therefore assess the robustness of obtained results against more realistic scenarios by injecting the gain calibration uncertainties, according to the requirements, into LiteBIRD simulated maps and assuming intermediate- and high-complexity sky models. In this case, we employ the so-called Multi-Clustering NILC (MC-NILC) foreground-cleaning pipeline and obtain that the impact of gain calibration uncertainties on $r$ is lower than the LiteBIRD gain systematics budget for the intermediate-complexity sky model. For the high-complexity case, instead, it would be necessary to tighten the requirements by a factor $1.8$.

Estimates of the frequency of planetary systems in the Milky Way are observationally limited by the low-mass planet regime. Nevertheless, substantial evidence for systems with undetectably low planetary masses now exists in the form of main-sequence stars that host debris discs, as well as metal-polluted white dwarfs. Further, low-mass sections of star formation regions impose upper bounds on protoplanetary disc masses, limiting the capacity for terrestrial or larger planets to form. Here, we use planetary population synthesis calculations to investigate the conditions that allow planetary systems to form only minor planets and smaller detritus. We simulate the accretional, collisional, and migratory growth of <inline-formula><tex-math id="TM0001" notation="LaTeX">$10^{17}$</tex-math></inline-formula> kg embryonic seeds and then quantify which configurations with entirely sub-Earth-mass bodies (<inline-formula><tex-math id="TM0002" notation="LaTeX">$\lesssim\!\! 10^{24}$</tex-math></inline-formula> kg) survive. We find that substantial regions of the initial parameter space allow for sub-terrestrial configurations to form, with the success rate most closely tied to the initial dust mass. Total dust mass budgets of up to <inline-formula><tex-math id="TM0003" notation="LaTeX">$10^2 \ \mathrm{ M}_{\oplus }$</tex-math></inline-formula> within 10 au can be insufficiently high to form terrestrial or giant planets, resulting in systems with only minor planets. Consequently, the prevalence of planetary systems throughout the Milky Way might be higher than what is typically assumed, and minor planet-only systems may help inform the currently uncertain correspondence between planet-hosting white dwarfs and metal-polluted white dwarfs.