Mathematical Physics
Categorical spin-networks: state-sum invariants of 4-manifolds from higher-gauge theory
Hank Chen, Zhian Jia, Ran Luo et al. (+1 more)
In this work, we define $(3+1)$-dimensional topological
quantum field theories (TQFTs) and their
lattice realizations with input data given by a pivotal fusion 2-category; more precisely, our framework applies in wider generality to presemisimple locally fusion pivotal tensor $2$-categories, which are equipped with a so-called shadow trace. We introduce a decoration of triangulated
manifolds by the input data, and develop a $20j$-symbol formalism for computing 4-simplex scattering amplitudes. We verify the topological invariance of 20$j$-symbol summations under the 4-dimensional Pachner moves. Furthermore, we also construct explicitly a 3-dimensional Levin-Wen-type
lattice Hamiltonian model realizing the state-sum invariant. Our construction can be understood as a higher-dimensional analogue of the
spin-networks construction for the Turaev-Viro invariant. Examples arising from $2$-groups are discussed from the perspective of higher gauge theory.
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All authors Hank Chen, Zhian Jia, Ran Luo, Wei Cui
Solar and Stellar Astrophysics
The Molecular Circumstellar Environments of Red Supergiants in Galactic Open Clusters
Mark A. Siebert, Elvire De Beck, Guillermo Quintana-Lacaci et al. (+4 more)
We aim to expand the sample of RSGs with direct measurements of circumstellar gas through millimeter observations of two of the largest coeval RSG populations in the
Galaxy: the open clusters RSGC1 and RSGC2. We present an interferometric molecular line study of 28 RSGs in RSGC1 and RSGC2 with ALMA. The primary targeted emission is CO $J=2-1$ and continuum, with additional thermal and maser SiO lines observed for RSGC2 targets. We measure terminal expansion velocities, systemic velocities, emission-region sizes, and provide updated
dust models and luminosities using the new long-wavelength constraints. Finally, we perform 1D radiative transfer modeling of CO rotational-line emission to estimate mass-loss rates. We detect $^{12}$CO toward six RSGs in RSGC2 and five in RSGC1. Except for DFK 52, the spatial distribution of all $^{12}$CO emission is relatively compact or unresolved. The obtained mass-loss rates range from $\log(\dot{M}/M_\odot\,\mathrm{yr}^{-1})=-5.5$ to $-3$, but are highly uncertain due to a lack of stringent constraints on the envelope sizes and temperatures. The lower-limit $\dot{M}$-values we obtain are high compared to standard empirical prescriptions and favor
dust models assuming a radiatively driven wind. DFK 49 is a clear outlier: its revised luminosity is the lowest in both clusters, yet it harbors a strong wind with $\dot{M}>10^{-5}\,M_\odot\,\mathrm{yr}^{-1}$. The CO emission regions are much smaller than expected from nearby RSGs and theoretical models, and suggest a unique phase structure for the CSM around RSGs in cluster environments. This work demonstrates the mutual utility of molecular line and
dust observations for constraining RSG winds, while highlighting the need for future spatially resolved, multi-tracer observations of RSGC targets to establish the physical structure of their circumstellar environments and improve mass-loss determinations.
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All authors Mark A. Siebert, Elvire De Beck, Guillermo Quintana-Lacaci, Theo Khouri, Maryam Saberi, Matthias Maercker, Wouter H. T. Vlemmings
Quantum Physics
Sharp Data-Processing Region for Quantum Conditional Rényi Entropies
Milad M. Goodarzi, Yucheng Bao and Marco Tomamichel
We study the three-parameter family of
quantum conditional Rényi
entropies $H_{\alpha,z}^\lambda$ introduced in Commun. Math. Phys. 407, 180 (2026). We prove that the previously established data-processing region is sharp. We then characterize the club-sandwiched family through a classical coarse-graining principle: within the full data-processing region, universal monotonicity under deterministic coarse-graining of the classical conditioned register holds if and only if $z = \alpha$. Finally, we establish
rigidity of entropic duality by showing that any universal duality relation for finite-dimensional tripartite pure states must satisfy the known parameter relations. Thus, the data-processing region, the club-sandwiched subfamily, and the duality transformation are each uniquely characterized by their respective universal properties.
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General Relativity and Quantum Cosmology
Circular orbits and particle collisions in the space-time of boson stars and their frozen states
Maria Chivers, Betti Hartmann, Katherine Horton et al. (+1 more)
In this paper, we discuss the dynamics of test particles in the space-time of spherically symmetric, charged
boson stars and their frozen states. These latter objects consist of a de Sitter core and a black hole exterior with a shell of finite thickness interpolating between the two. We discuss charged and uncharged massive particles, find the ISCOs and determine whether collisions of massive particles close to the core of (frozen)
boson stars can lead to large center of mass energies. We also discuss massless test particles and find that
photons rings as well as light points are possible in the space-time of frozen
boson stars. We compare our results with those in the corresponding Reissner-Nordstroem space-time and point out differences.
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All authors Maria Chivers, Betti Hartmann, Katherine Horton, Yves Brihaye
Statistical Mechanics
The memory equation of a characteristic function in surface diffusion
S. Miret-Artés
The decay of a density wave, the
Fourier component of the adparticle density seen by a coherent probe, obeys in an interacting adlayer an exact
memory equation of Mori's form, determined by the local rate and the
memory function. Because the density is conserved, the correlation function is a characteristic function, and the kernel is built from that of a single jump; positivity and normalization then make the local rate and the
memory function
equilibrium averages, whatever the interaction. The local rate obeys an exact sum rule, which makes de Gennes narrowing a
theorem on the
lattice and gathers the interaction into one effective hop rate. Detailed balance makes the decay a superposition of relaxation modes, approached from below by a convergent hierarchy of closed forms. The theory fixes the local rate, the
memory function and the relaxation spectrum. The experiment provides the static structure factor and the decay, recorded from the instant of scattering through a ballistic regime, a jump regime in which the
memory acts, and a diffusive regime. A single exponential fitted, as experiments do, over a time interval in the diffusive regime gives the slowest relaxation rate, the constant rate of that regime, and not the local rate. The correlation time, defined as the area beneath the normalized decay, needs no time interval and is the mean inverse relaxation rate. Under a standard condition on the jump rates, met in one-dimensional
diffusion when the rate of leaving a site is independent of the site reached, the correlation time, the static structure factor and the
lattice geometry give the effective hop rate at long wavelength, with no model or fit and with a parameter-free test. There the sum rule becomes a Darken-type relation.
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High Energy Physics (Phenomenology)
Natural Saturation Of The Sterile Neutrino Dark Matter Resonant Production By a High Lepton Flavor Asymmetry In Primordial Plasma
Dmitry Gorbunov and Dmitry Kalashnikov
Sterile
neutrinos remain a well-motivated dark-matter candidate whose cosmological abundance can be enhanced by resonant active–sterile conversion in the presence of a
lepton asymmetry in
primordial plasma. In the standard picture, a larger initial asymmetry increases the matter potential and can therefore promote resonant production. However, the same increase also shifts the resonance to later stages of the cosmological
evolution when the
plasma temperature is lower. We show that this delayed production epoch can overlap with the onset of active
neutrino oscillations, which redistribute the
flavor asymmetries and may substantially reduce, or in some cases nearly erase, the
lepton asymmetry needed for a successful resonant sterile-
neutrino production. This interplay provides a natural saturation mechanism for the final sterile-
neutrino abundance: beyond a certain range of initial asymmetries, increasing the
primordial asymmetry no longer leads to a proportional increase in the produced dark-matter density. We identify this effect as an additional constraint on resonant sterile-
neutrino production at large
lepton asymmetry and discuss its dependence on the
flavor structure of the initial asymmetry and on the background cosmological
evolution. Our numerical results reveal two order of magnitude range in sterile-active
neutrino mixing parameter $\sin^2(2\theta)$ presently consistent with the resonant mechanism of the dark matter sterile
neutrino production. It must be investigated by the next generation X-ray
telescopes to fully explore this mechanism and corresponding minimal models suggesting sterile
neutrinos as viable dark matter. We also consider pion condensation at large
flavor lepton asymmetries, which may lead to a first-order QCD phase transition and associated gravitational-wave production in the early Universe.
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Optics
Probing the formation of femtosecond laser-induced periodic surface structures on silica films by ultrafast small-angle X-ray scattering
Dominik Kaczmarek, Jean-Luc Déziel, Thies Johannes Albert et al. (+16 more)
Ultrashort X-ray pulses, as provided by X-ray Free Electron
Lasers (XFELs), offer unique opportunities to probe the formation of
laser-induced nanostructures with sizes even below the optical diffraction limit, with sub-micometer and sub-picosecond spatial and temporal resolution. Using ultrafast small-angle X-ray scattering (SAXS), we probe the formation of nanoscatterers and nanocracks in reciprocal space as they evolve into different types of
laser-induced periodic surface structures (LIPSS) on silica films. Our focus is on the dynamics and
evolution of nanoscatterers and high spatial frequency LIPSS (HSFL), with spatial periods below 100 nm. Our experiments include an in-situ analysis of the pulse-by-pulse
evolution of HSFL at a fixed sample location, as well as fs time-resolved delay and fluence scans using an ultrafast pump-probe scheme. We find that nanoscatterers and periodic nanocracks form at delay times of hundreds of picoseconds and subsequently evolve into HSFL. At low
laser fluences, inter-pulse incubation effects become important during multi-pulse irradiation. Simultaneously, inter-pulse feedback leads to an ordering and improve the regularity of the HSFL. The experiments are complemented by theoretical analyses, including numerical Finite-Difference Time-Domain (FDTD) simulations. These combined analyses allow us to propose a five-stage model of LIPSS formation on silica films upon irradiation with fs-
laser pulses.
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All authors Dominik Kaczmarek, Jean-Luc Déziel, Thies Johannes Albert, Matthias Weise, Jerzy Antonowicz, Robert Carley, Devesh Chopra, Loïc Le Guyader, Laurent Mercadier, Giuseppe Mercurio, Roman Minikayev, Mianzhen Mo, Andreas Scherz, Ryszard Sobierajski, Yanwen Sun, Martin Teichmann, Peter Zalden, Klaus Sokolowski-Tinten, Jörn Bonse
High Energy Astrophysical Phenomena
A statistical hardness classification of ultraluminous X-ray sources using long-term Swift/XRT monitoring
Sinan Allak, Wei Yu, Menglei Zhou et al. (+2 more)
We characterize long-term hardness behavior in 29 ultraluminous X-ray sources (ULXs) using over 3500 archival Swift/XRT observations. We classify observations as soft-band dominated, hard-band dominated, or uncertain from the hardness ratio (HR; 1.5–10/0.3–1.5 keV count rates) and its confidence bounds. We derive $f_{\rm soft}$ and $f_{\rm hard}$ and define the Crossing Index (CI) as the fraction of consecutive confidently classified observations on opposite sides of $HR=1$. We analyze these descriptors with rule-based classification and unsupervised hierarchical clustering. The rule-based analysis identifies eight soft-band-dominated, five hard-band-dominated, and 16 mixed-band systems; clustering yields a similar three-group structure. Known or candidate accretor types tend to occupy band-dominated groups, whereas unknown accretors are more common in the mixed-band group. All four sources with reported long-term X-ray modulation discussed in an orbital or super-orbital context are classified as mixed-band. The three-cluster solution is preferred in 25 of 29 leave-one-out trials, while bootstrap tests find the band-dominated groups more stable than the mixed-band group. As the classification uses observed count rates, the groups represent Swift/XRT signatures rather than intrinsic spectral states. Response-folding tests show that modeled HR depends on absorption column density and
photon index.
Bayesian reanalysis of a representative low-count source reduces CI from 56.3% to 38.5% while preserving its mixed-band classification. Random downsampling produces no systematic shift in CI; halving the observations changes median CI by at most $\sim10\%$ across four sources. Larger samples with independent absorption constraints can test links among these observational classes, accretor type, long-term periodic modulation, and other X-ray properties.
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All authors Sinan Allak, Wei Yu, Menglei Zhou, Honghui Liu, Andrea Santangelo
High Energy Physics (Experiment)
Suitability studies of exotic muon decay at the High Intensity heavy-ion Accelerator Facility
Lingzhi Dong, Jinning Li, Leyun Gao et al. (+8 more)
We present a detailed feasibility study of exotic
muon decay searches using the
muon beam at the High Intensity heavy-ion Accelerator Facility (HIAF). For the decay channel mu to eX0, where X0 denotes a new
boson featuring LFV couplings, the produced electron carries very low energy when the mass of X0 approaches the
muon mass, making detection challenging. Nevertheless, the high-energy beam at HIAF can boost these electrons up to a measurable energy range. The detector system proposed here comprises front-end scintillators for particle identification (PID) and a main detector consisting of an RPC stack to track decay products and a scintillator for energy measurement. Leveraging the kinematic properties of low momenta and small emission angles of signal electrons, we employ optimized momentum and angular acceptance cuts on the RPC detector to efficiently suppress background events. With this strategy, we obtain an upper limit of 1e-5 on the branching ratio of the exotic
muon decay at 95% confidence level, achieving state-of-the-art sensitivity.
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All authors Lingzhi Dong, Jinning Li, Leyun Gao, Cheng-en Liu, Yu Xu, Xuecheng Zhang, Liangwen Chen, Qite Li, Chen Zhou, Qiang Li, Zhiyu Sun
Strongly Correlated Electrons
Criticality enabled long-range order in a U(1)-symmetric spin-1 Heisenberg chain with biquadratic interactions
Natalia Chepiga and Fabian H.L. Essler
In a recent paper Nahum argued on the basis of a renormalization-group analysis that, contrary to standard lore, ground states of 1D
spin chains with short-range interactions can spontaneously break U(1) “easy-plane”
spin rotation
symmetry. True long-range order of $(S^x,S^y)$ arises at the phase transition between two quasi-long-range-ordered phases. Here we present detailed numerical results for an anisotropic
spin-1 chain model. We find a magnetization exponent $\beta\approx0.29$, consistent with the $\epsilon$-expansion prediction $\beta\approx0.28$, a divergence of the Luttinger parameter on approaching the transition from both sides with an exponent that we relate to Nahum's transition, and finite-size spectra consistent with a dynamical critical exponent $z\approx2$. Our results support the critical behavior predicted by Nahum's field theory.
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Atomic Physics
Highly elastic collisions of ultracold asymmetric top molecules in a static electric field
Reuben R. W. Wang
We propose that the application of static electric fields to reactive CaNH$_2$ molecules can result in large ratios of elastic to lossy collisions at ultracold temperatures. In the first rotationally excited
manifold, the asymmetric top structure of CaNH$_2$ results in a $\approx 226$ MHz splitting of the opposite parity $K$-doublet states. This modest splitting allows electric fields below a kilovolt per centimeter to polarize the molecules and induce long-range dipole-dipole interactions. By increasing the electric field, we find that dipole-dipole attraction can become sufficiently large to induce weakly bound octatomic field-linked states of [CaNH$_2$]$_2$. In the absence of these field-linked states, we identify select molecular states where dipolar interactions allow elastic collisions to dominate over lossy collisions by up to three orders of magnitude, while maintaining loss rate coefficients at the $10^{-14}$ cm$^3$s$^{-1}$ level. These results establish that evaporative cooling is a viable route to
quantum degenerate gases of
laser coolable asymmetric top molecules. Access to such low
entropy ensembles of asymmetric top molecules holds promise to push the frontiers of
quantum simulation, state-resolved chemistry, and searches for beyond the Standard Model physics.
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Quantum Physics
Excitation exchange between identical atoms having arbitrary angular momentum
P. R. Berman and Zeyuan Wang
Equations of motion are derived for excitation exchange between two atoms having arbitrary angular momentum.
Quantum Physics
Causal Query Compression for Lindblad Dynamics: Optimal Queries and Nearly Linear Local Simulation
Jacob Kitchen
We construct a causal query compiler for time-dependent Lindblad dynamics and establish query and gate bounds under distinct input models. With coherent block encodings of the
Hamiltonian and individual jump operators, a Lipschitz generator can be simulated to diamond-norm error $\varepsilon$ using $O(1+\tau+\log(1/\varepsilon)/\log(e+\log(1/\varepsilon)/\tau))$ controlled queries, where $\tau=T(\alpha_H+\sum_\mu\alpha_\mu^2)$. This bound is independent of the time-grid size and is worst-case optimal for $\tau\ge1$. Weak active entry and clean return yield a factorial history tail; combining two reuse lengths removes the auxiliary input. A three-call polar correction supplies the Lindblad
cells. The compiler also characterizes the minimum oracle action of bounded adaptive Markovian protocols by
quantum query complexity and the general adversary bound, up to constant factors. For finite-range dynamics on $n$
lattice sites, efficient coherent evaluation of the local
matrices and fixed local parameters give $O(n(T+1)\operatorname{polylog}X)$ elementary gates, where $X=\max\{e,n(T+1)(1+K_t+B)/\varepsilon\}$, for piecewise Hölder generators with fixed exponent, local variation bound $K_t$, and at most $B$ breakpoints per term. The jumps need not commute. This gate bound includes evaluation, arithmetic, selection, routing, and environment storage. Its proof combines a spatial decomposition on a common bath, compilation on occupied inputs, and routing on compressed records. Reusing bath storage between short segments gives depth $(T+1)\operatorname{polylog}X$ and space $n\operatorname{polylog}X$.
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Quantum Physics
Residual Fisher Information in Measurement-Error Uncertainty
Masayuki Ohzeki and Taiga Suzuki
Measurement error in the Watanabe-Sagawa-Ueda formulation is the excess estimation error of a classical record over the
quantum statistical limit. We show that, at the
quantum-instrument level, this excess has an exact decomposition. The record-only error
matrix equals a residual-aware error
matrix plus a positive Schur-complement term fixed by Fisher information left in the unread post-measurement system. Thus measurement error separates into intrinsic instrument loss and record-restriction loss
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High Energy Physics (Theory)
Fate of Bouncing Singularities at Finite $G_N$
Zohar Komargodski
The
gravity approximation to a thermal two-point function can develop a complex-time singularity associated with a trajectory that reaches the black-hole singularity. We show that the corresponding singularity is absent at finite $G_N$. This is done by extending Conformal Field Theory analyticity properties to the second sheet (and to the universal cover). We also put two different upper bounds on the amplitude of the correlator at the would-be singularity, by certain finite partial sums, and by a certain partition function on a
manifold with nontrivial
topology, where two thermal geometries are glued. We discuss the possible implications for the black hole singularity.
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Astrophysics of Galaxies
SQuIGG$\vec{L}$E: Ubiquitous Cool Gas Outflows with Large Mass-Loading Factors in $z\sim0.7$ Post-starburst Galaxies
Yuanze Luo, Justin S. Spilker, David J. Setton et al. (+13 more)
While recent James Webb Space
Telescope studies have highlighted cool gas
outflows as an important mechanism for rapid quenching at $z\gtrsim2$, such space-based spectroscopic samples remain limited in size. In this work, we search for and characterize cool gas
outflows traced by Fe II $\lambda\lambda$2586,2600 and Mg II $\lambda\lambda$2796,2803 absorption in post-starburst
galaxies (PSBs) at $0.5<z<0.9$, which are accessible to ground-based spectroscopy. Utilizing the SQuIGG$\vec{L}$E survey containing over 1300 PSBs, we stack spectra in bins of
stellar mass, (specific)
star formation rate, burst mass, burst mass fraction, and time since quenching. We observe blueshifted line centroids indicative of
outflows in all stacks except the one containing
galaxies that quenched more than 260 Myr ago.
Outflow velocities decline with increasing time since quenching, while showing little correlation with other
galaxy properties. The inferred
outflows have large mass loading factors of 1 – 120, maximum velocities above the interstellar medium escape velocities of their host
galaxies, and energy and momentum fluxes exceeding those expected from the current
star formation. Our results suggest that cool gas
outflows are ubiquitous in intermediate-
redshift PSBs and are likely relic
outflows launched by previous starburst or AGN activity. These
outflows have the potential to quench
star formation by transporting gas into the
galactic halos, consistent with
outflows playing an important role in rapid quenching from intermediate to high
redshift.
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All authors Yuanze Luo, Justin S. Spilker, David J. Setton, Timothy Heckman, Rachel Bezanson, Vincenzo R. D'Onofrio, Alex Geiger, Andy D. Goulding, Jenny E. Greene, Kate Rowlands, Katherine A. Suess, Elizabeth Taylor, Margaret E. Verrico, Andrew Weldon, Vivienne Wild, Pengpei Zhu
Astrophysics of Galaxies
SQuIGG$\vec{L}$E: Spatially resolved NIRSpec Pa$\alpha$ reveals that the most CO-luminous, $z\sim0.7$ post-starburst galaxies exhibit falling—but still active—star formation behind optically thick dust
David J. Setton, Jenny E. Greene, Rachel Bezanson et al. (+13 more)
One of the fundamental uncertainties in the study of
galaxies at the interface between
star formation and quiescence–post-starburst
galaxies–is their instantaneous
star formation rate. While these
galaxies appear quiescent in the rest UV-optical, many of the youngest systems are highly CO luminous, implying dense molecular gas, and potentially
star formation. However, their instantaneous
star formation rates have proved elusive, as measurements with rest-optical emission lines or UV-to-IR SED fitting yield order-of-magnitude uncertainty. Here, we present JWST/NIRSpec G395M/170LP integral field spectroscopy of the three most CO-luminous massive
galaxies in the SQuIGG$\vec{L}$E survey, spatially resolving Pa$\alpha$/Br$\gamma$/Br$\beta$ to map the
dust-corrected
star formation rate. We find that these
galaxies host
star formation rates of $27-80$ $M_\odot \ \mathrm{yr^{-1}}$, though $\sim30-40\%$ of the emission may arise from non-
star-forming ionization (AGN or shocks), implied by high [FeII]/Pa$\alpha$ in central spaxels. We also find effective $A_{\mathrm{Pa}\alpha}\sim1$ and individual $\sim700$ pc spaxels with $A_{\mathrm{Pa\alpha}}\sim2$, implying significant
dust obscuration of nebular regions that contribute little to the rest-optical lines. These
galaxies are not consistent with total quiescence; the measured
star formation rates place these
galaxies on or above the main sequence. However, their
star formation rates are significantly lower ($\sim0.5-1$ dex) than the peak
star formation rates inferred from spectrophotometric fitting. We propose that the CO luminous post-starburst phase represents the last gasp of
star formation in
galaxies on the rapid quenching pathway, and that
dust-obscured
star formation,
outflows, and (speculatively) an uncertain CO-to-H2 conversion reconcile their gas exhaustion with observed timescales of fading.
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All authors David J. Setton, Jenny E. Greene, Rachel Bezanson, Katherine A. Suess, Justin S. Spilker, Vincenzo R. D'Onofrio, Elia Cenci, Robert Feldmann, Alex J. Geiger, Andy D. Goulding, Mariska Kriek, Anika Kumar, Yuanze Luo, Desika Narayanan, Margaret E. Verrico, Pengpei Zhu
Astrophysics of Galaxies
A solution to the paradox of youth in the Galactic centre
Rodrigo P. Silva, Alexandre C. M. Correia, Tjarda C. N. Boekholt et al. (+1 more)
The supermassive black hole at the
Galactic centre, Sgr A*, is surrounded by an S cluster of young
stars. These
stars are predominantly B-type
stars, but their origin remains uncertain. Unlike massive
stars in the
Galactic field, which exhibit a binary fraction of about $70\%$, those in the S cluster show a significantly lower fraction. It is key to understand this discrepancy for constraining their formation. We show that the binary deficit arises naturally from dynamical interactions between
stellar binaries and Sgr A* in an in situ formation scenario. Using K-amplitude data, we derived an observational binary fraction of $f_{\mathrm{obs}} = 0.43 \pm 0.09$ for the S-cluster
stars. Our dynamical modelling predicts that interactions with Sgr A* cause $18\%$ of the binaries to merge, $20\%$ to be disrupted, and $62\%$ to survive, yielding a theoretical binary fraction of $f_{\mathrm{theo}} = 0.38 \pm 0.10$. The predicted binary fraction with distance from Sgr A* is also consistent with independent observational constraints. These results show that the decline in binarity towards the
Galactic centre is driven by stronger
tidal forces, and they support an in situ origin of the S cluster in the same event that produced the
Fermi bubbles.
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All authors Rodrigo P. Silva, Alexandre C. M. Correia, Tjarda C. N. Boekholt, Paulo J. V. Garcia
High Energy Physics (Phenomenology)
Improving predictions for the $pp \to t\bar{t}W^+$ process at the LHC with the MINLO method
Nikolaos Dimitrakopoulos
We compare the standard NLO and $\texttt{MiNLO}$ approaches for the full off-shell $pp \to t\bar{t}W^+ + X$ process at the LHC, at both the integrated and differential cross-section levels. Contrary to NLO, in the $\texttt{MiNLO}$ approach, which is now also available within the HELAC-NLO framework, renormalization and factorization scales are dynamically extracted and Sudakov form factors are incorporated. Results are particularly presented for the $pp \to t\bar{t}W^+j$ process at NLO accuracy in perturbative QCD using two different scale choices. Merged predictions up to two jets to improve the overall modeling of the full off-shell $pp \to t\bar{t}W^+ + X$ process are also discussed.
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Astrophysics of Galaxies
H2 emission in the Orion Bar, NGC7023 and the Horsehead Nebula observed with the James Webb Space Telescope
M. Zannese, A. Sidhu, A. Guerras et al. (+25 more)
Molecular hydrogen (H2), the most abundant molecule in the interstellar medium, is a handy tool to study Photodissociation Regions. The JWST, with its high spatial resolution, sensitivity, and wavelength coverage, provides unique access to the detection and spatial morphology of the H2 rotational and rovibrational lines. Our goal is to analyze H2 line emission detected with JWST in several PDRs (the Orion Bar, NGC7023, and the Horsehead Nebula) to constrain the physical structure of dissociation front, and compare the impact of the ultraviolet field and the gas density across different regions. The analysis of H2 spatial morphology reveals similar filamentary structures across all regions. Spatial shifts between H2 lines (0.5") are observed and linked to differences in excitation mechanisms (thermalized vs FUV-pumped lines) and the temperature gradient. Despite differences in incident irradiation conditions, analysis of H2 rotational excitation yields high gas temperatures that are similar across the three PDRs. This is expected for a certain regime of excited PDRs (such as Orion and NGC7023), where the G0 at the DFs and the density are similar. However, it is surprising for less excited PDRs like the Horsehead Nebula. OPRs in the rotational and rovibrational levels differ across the three PDRs. We also used H2 rovibrational lines and the 0-0 S(3) line to estimate the visual extinction across the field of view, yielding markedly different results that constrain both the geometry and the grain composition. Due to the complex 3D geometry, H2 emission is observed throughout the FOV and is dominated by the thin UV illuminated layer, making H2 an unreliable tracer of gas temperature in deeper and coolers molecular layers of the PDR. Therefore, H2 emission is not sufficient to trace the possible temperature and density gradient across PDRs and must therefore be associated with other tracers.
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All authors M. Zannese, A. Sidhu, A. Guerras, M. Pound, M. Wolfire, A. G. G. M. Tielens, E. Peeters, E. Habart, A. Abergel, M. Baes, O. Berné, C. Boersma, E. Bron, J. Cami, R. Chown, E. Dartois, P. Dell'Ova, J. R. Goicoechea, K. D. Gordon, P. Guillard, O. Kannavou, K. Misselt, N. Monnier, A. Noriega-Crespo, T. Onaka, D. Van de Putte, L. Verstraete, A. N. Witt
Instrumentation and Methods for Astrophysics
MATISSE-py: a high-level Python interface for efficient, automated VLTI/MATISSE data reduction
A. Soulain, A. Matter, P. Berio et al. (+4 more)
The Multi AperTure mid-Infrared SpectroScopic Experiment (MATISSE) at the Very Large
Telescope Interferometer (VLTI) delivers rich mid-infrared interferometric
datasets that are reduced through a robust, multi-stage ESO pipeline. In its native form, however, the reduction relies on command-line calls to esorex, hand-edited set-of-files (SOF) and configuration files, and manual iterations that are difficult to automate, reproduce, or integrate into modern Python workflows. We present MATISSE-py, a modular Python interface that wraps the official ESO esorex recipes behind a single, user-friendly matisse command. It automates discovery, reduction, calibration, and inspection of the data, and ships as a tested, open-source package built on industry-standard practices. Beyond convenience, MATISSE-py introduces science-grade improvements developed over seven years of MATISSE operations: visibility- and photometry-factor (V-factor and P-factor) corrections derived from the
GRAVITY fringe tracker to mitigate residual visibility losses, per-baseline data filtering, beam-commuting-device (BCD) "magic-number" corrections, and an absolute spectrophotometric flux calibration using state-of-the-art reference spectra. On faint targets observed under degraded conditions, the V-factor correction recovers up to a few percent of lost visibility and reduces the statistical uncertainties by nearly 20%, while yielding calibrator diameters that are consistent across BCD modes. MATISSE-py thus consolidates the consortium's expertise into a maintainable package and shortens the reduction-to-science loop for the community.
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All authors A. Soulain, A. Matter, P. Berio, F. Millour, B. Lopez, R. Petrov, S. Lagarde
Quantum Physics
Quantum environment afterglow from broadband excitation spectroscopy in superconducting qubits
J. R. Guimarães, Y. Liu, Y. Gao et al. (+10 more)
Understanding the
qubit environment is central to fault-tolerant superconducting
quantum computation. Characterization typically relies on relaxation, leaving excitation largely underexplored. Here, we access this information with time-resolved broadband excitation spectroscopy. The resulting
qubit excitation spectrum reveals a highly structured landscape, interspersed with cold regions. Combined with postselection, this technique enables full reconstruction of the noise power spectral density (PSD) and separates
quantum from classical noise. With feed-forward, it exposes long-lived two-level-systems (TLSs), whose relaxation times span tens of microseconds to milliseconds - uncovering an intrinsic link between the
qubit-TLS coupling and TLS relaxation. The data suggest that the long-lived TLSs are intrinsic to the
qubit environment, and can cause excitation that lasts for many
qubit operation cycles. Consequently, the environment retains a
memory of prior dynamics, and properties like gate fidelity become non-Markovian and protocol-dependent. The presented approach enables identifying and bypassing the hidden roadblocks formed by long-lived TLSs in fault-tolerant
quantum computation.
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All authors J. R. Guimarães, Y. Liu, Y. Gao, Y. Haddad, A. Galicia, D. A. Volkov, J. T. Schmieder, H. Bhardwaj, M. Neis, J. Cereijo, M. Jerger, P. A. Bushev, R. Barends
Materials Science
High-throughput computational discovery of CuI-based ternary $p$-type transparent conductors
Michael Seifert, Miguel A. L. Marques and Silvana Botti
P-type transparent conducting materials (TCMs) remain scarce, limiting progress in transparent electronics and tandem photovoltaics. Here, we perform a high-throughput computational search across CuI-based ternary X–Cu–I compounds using the minima hopping method combined with density functional theory. Filtering for thermodynamic stability, optical transparency, and light hole effective mass, we identify 58 candidate p-type TCMs, of which 49 are previously unreported. Twenty are p-type degenerate
semiconductors with intrinsic hole carriers, including Cu$_2$FI$_2$ (calculated gap 3.75 eV, hole effective mass $0.262\,m_0$). We further use this
dataset to revisit the chemical modulation of the valence band (CMVB) design rules, originally formulated for Cu-based delafossite
oxides. Four generalizations emerge: linear Cu coordination is not required, as tetrahedral coordination (CN = 4) is compatible with p-type TCM character; the mechanism extends to halide-based systems with I $5p$ anion states; the Cu $d$ state energy center $\epsilon_d$ is a quantitative descriptor for valence band dispersion; and Cu undercoordination in monovalent-anion hosts drives intrinsic p-type carrier generation through stoichiometric charge balance. These results establish a generalized computational framework for the design of p-type halide TCMs.
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High Energy Physics (Theory)
Revisiting three-dimensional GLSMs and K-theoretic I-functions
Taro Kimura, Yinda Li and Xiaohan Yan
We revisit the correspondence between three-dimensional gauged linear sigma models and K-theoretic Gromov-Witten theory. We show that the K-theoretic Hori-Vafa formula for the grassmannian arises from the three-dimensional gauge theory upon including an appropriate anomaly-cancellation factor. Furthermore, we derive K-theoretic I-functions for isotropic grassmannians by incorporating symmetric and anti-symmetric tensor representation fields together with suitable boundary conditions.
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Atmospheric and Oceanic Physics
Learning Aerosol Coagulation Dynamics in Latent Space with a Scale-Covariant Neural ODE
Wenhan Tang, Ruqi Yang, Jeffrey H. Curtis et al. (+5 more)
Particle-resolved aerosol models preserve the joint size-composition structure that governs cloud activation, optical properties, and freezing, but their computational cost limits their use in large-scale atmospheric models. We extend AeroMELD from a compact representation of aerosol populations to a prognostic model of coagulation. The resulting AeroMELD-Coag advances nine learned coordinates for population shape and one for total particle number through a scale-covariant neural ordinary differential equation that incorporates the known concentration dependence of coagulation. Across 2,000 held-out trajectories spanning 48 h, median symmetric errors are 3.5% for latent shape and 0.52% for total number. This ten-coordinate state also retains the evolving size-resolved composition and associated cloud-condensation-
nuclei (CCN) activation, optical properties, and frozen fraction. Compared with the evaluated 20-bin sectional model with 320 prognostic coordinates, AeroMELD-Coag lowers pooled mean CCN activation error from 1.98% to 1.38% and frozen-fraction error from 1.72% to 0.56%. In a matched integration
benchmark, GPU integration time per trajectory, amortized over a batch, is more than three orders of magnitude lower than for both single-core CPU references. These coagulation results provide a proof of concept for advancing aerosol microphysics efficiently in a compact learned state while retaining information about aerosol mixing state. They establish a foundation for future large-scale atmospheric models to represent aerosol microphysics with greater mixing-state detail within practical computational budgets.
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All authors Wenhan Tang, Ruqi Yang, Jeffrey H. Curtis, Ehsan Saleh, Lekha Patel, Peter A. Bosler, Nicole Riemer, Matthew West
Materials Science
Multiscale computational study of the dielectric response of semi-crystalline polyethylene with chemical defects
Roshal Perepadan Shaju, Guido Roma and Xavier Colin
Polymers are widely used as functional insulating materials, but predicting their dielectric behavior is challenging because multiple mechanisms, acting across different spatial and temporal scales, contribute to their response. In polyethylene (PE), one of the most common
polymers, electronic, atomic, and mesoscale dynamics must all be considered. In this work, semicrystalline models of polyethylene were developed and investigated using a multiscale approach.
Quantum simulations were employed to describe electronic and vibrational contributions to the dielectric response, while classical molecular dynamics simulations captured the behavior of
polymer chains at room temperature and frequencies down to the 10-100 MHz range. The study focuses on the impact of
radio-oxidation defects on the dielectric properties of polyethylene.
Quantum calculations reveal how electronic and vibrational contributions depend on the local atomic environment surrounding these defects. Comparison with molecular dynamics results highlights the influence of temperature on the static dielectric constant. Structural analyses further assess the effect of each defect type on PE crystallinity. Analysis of dipolar correlation functions shows that different defects interact with one another and with the
polymer matrix in distinct ways, affecting permittivity and dielectric loss peaks. For all defect types, defect-defect interactions provide the largest contribution to dielectric response. While most oxidized groups exhibit positive coupling with the PE
matrix, alcohol defects display a negative cross-correlation, partially offsetting their impact on the dielectric properties. Our results also show that ketone groups produce the largest dielectric loss between the defects studied.
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Soft Condensed Matter
Vibrational Mpemba relaxation in a linear damped elastic system
Kiwamu Yoshii and Satoshi Takada
We show that a linear damped elastic system can display a Mpemba-like reversal of vibrational relaxation without any nonlinear constitutive response or amplitude-dependent damping. The mechanism is purely modal. For a one-dimensional Kelvin–Voigt elastic medium, the decay rate of the $n$-th vibrational mode scales as $\gamma_n\propto n^2$. We formulate relaxation in terms of a positive modal envelope energy, thereby excluding crossings caused merely by oscillation phase. A one-parameter family of initial states is then constructed such that increasing the initial elastic excitation simultaneously reduces the projection onto the slow fundamental mode. In the invariant two-mode subspace, the relaxation-order crossing is obtained analytically and, for this family, occurs at a universal dimensionless time independent of the selected pair of initial states. In the limiting case where the slowest mode is absent, the dominant relaxation rate changes discontinuously, yielding a direct vibrational analogue of the strong Mpemba effect. We further show that the same relaxation-order reversal occurs in the ordinary mechanical vibrational energy, which decreases monotonically despite retaining the oscillatory dynamics of the underlying modes.
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Quantum Gases
Electron lattice potentials for ultracold atoms using circular Rydberg orbitals
Aileen A. T. Durst, Einius Pultinevicius, Homar Rivera-Rodríguez et al. (+3 more)
Recent advances in experiments using individually trapped atoms have enabled precise control over circular Rydberg electrons with exceptionally long lifetimes. We show that these
giant and stable electron orbits can form toroidal
lattice potentials for ultracold atoms with a period set by the electron's de Broglie wavelength. Unlike conventional static optical
lattices, this electron
lattice is formed via the electron-atom interaction, which mixes Rydberg circular states with opposite azimuthal phase winding into a standing electronic matter wave. The
lattice phase is thereby intrinsically coupled to the atom position. For a pair of atoms, this results in ballistic tunneling motion in the two-atom spatial correlations along the ring, while the single particle dynamics is essentially free rotation. We simulate the dynamics for an experimentally realistic setting that exploits optical tweezers for individual atom control. Our results open a route toward incorporating long range atom-atom interactions mediated by a single electron and, ultimately, realizing small Bose and
Fermi gases confined in these microscopic electronic atom traps.
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All authors Aileen A. T. Durst, Einius Pultinevicius, Homar Rivera-Rodríguez, Tilman Pfau, Matthew T. Eiles, Florian Meinert
Quantum Physics
Locality and filter design for dissipative ground-state preparation
Samuel J. Elman
Ground-state preparation is a fundamental challenge in
quantum many-body physics, chemistry and materials science. Dissipative state-preparation techniques engineer a Lindbladian coupling to a bath that drives the system to its ground state, needing no initial overlap. Their cost is dominated by the
Hamiltonian simulations inside the filtered jump operators, since each jump is a weighted sum of Heisenberg-evolved copies, or branches, of a coupling operator. We reduce this cost by following three simple observations to their logical end. First, on a fixed time grid, linear programming optimises the branch weights, trading the heating response against the
circuit cost. Second, Lieb–Robinson bounds let each branch evolve on a patch whose radius grows with its duration. Third, if the dynamics converges quickly and truncation changes the jumps only slightly, the stationary state stays near the ground state even on patches smaller than the light cone. We validate our approach numerically. On a grid of $81$
evolution times, the optimised filter reduces the worst-case heating response, or leakage, more than $116$-fold at equal cost. Across fifteen molecules and six chains, the cost falls by 27 to 56% at matched design-grid leakage; at matched cost, the molecular leakage falls by a factor of $2.9$ to $2\times10^{3}$. Density-
matrix simulations show high ground-state fidelity for both filters, and on Ising and Hubbard chains the cheaper filter keeps a ground-state population of at least $0.89$ on patches of three or four sites. The same patches fail on a Heisenberg chain whose truncation error falls more slowly with patch size and whose Lindbladian gap is 12 times smaller than the Ising chain's, pointing to a role for the gap in how far patches can be truncated. At fixed radius the per-branch cost becomes independent of system size, reducing the cost of dissipative state preparation.
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Quantum Physics
Steady–State Current Signatures of Strong Light–Matter Coupling in Single–Molecule Junctions
Kritanjan Polley and Norah M. Hoffmann
Strong light-matter coupling offers exciting opportunities for controlling molecular properties, yet resolving single-molecule behavior from collective effects remains a challenge. Recent experiments in scanning tunneling microscope break junctions (STM-BJs) have demonstrated strong light-matter coupling at the single-molecule level. Because STM-BJs provide direct access to molecular-junction currents, we investigate whether strong coupling leaves a measurable fingerprint in transport, potentially probing polaritonic states beyond optical spectroscopy. Using a semiclassical mapping approach for nonequilibrium
quantum transport, we find that steady-state current indeed carries a direct signature of single-molecule strong coupling. We test the robustness of this signature against electrode connectivity,
nuclear motion, spatially structured electromagnetic modes, and solvent effects. While environmental factors and
nuclear motion reshape the signature, the current is not a passive response but is actively influenced by coupled molecular dynamics. Our work establishes current as a tool to interpret and control strong light-matter interactions in nanoscale junctions.
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