High Energy Physics (Theory)
Higher anomalies, compressing SPTs and cohomology operations
Shani Nadir Meynet and Elias Riedel Gårding
We explicitly compute and tabulate the suspension map for
cohomology operations, applying it to the dimensional reduction of anomalies and higher group structures of generalised
symmetries in
quantum field theories and
lattice systems. In a
quantum system with a discrete $p$-form
symmetry, we can restrict the
symmetry defects to a codimension-$q$ subspace of spacetime, or equivalently confine the gauge field to a slab whose thickness approaches zero. This results in a $(p-q)$-form
symmetry on the subspace. We determine the fate of two important properties of
symmetries under this process. First, we compute the anomaly of the reduced
symmetry, or the higher anomaly of the original
symmetry, which acts as an obstruction to higher gauging and onsiteability. Second, for two
symmetries forming a higher-group structure, encoded as a Postnikov class, we compute the reduced higher-group structure, which may or may not be trivial. Both cases are captured by the $q$-fold iteration of the
cohomology suspension $\Omega$, also known as the loop functor or transgression, in the
cohomology of Eilenberg–MacLane spaces. Classical results state that $\Omega$ is an isomorphism in a stable range and annihilates mixed anomalies. To calculate $\Omega$ over a base ring which is not a field, we make use of small models for the chain DGAs of Eilenberg–MacLane spaces, pioneered by Cartan and Moore, whose results we review and extend. The critical added step is the improvement of a mod $p$ chain contraction to the $p$-local integers, obtained via a $p$-adic series. We automate the computations in a software package emcm, and provide extensive tables of the results. Finally, to make contact with explicit cochain formulations of
cohomology operations, we demonstrate how to calculate cup products and certain cup-$i$ products in this framework.
Read the full abstract ▾
Quantum Physics
Exact learning of quantum noise with tensor networks
Nicola Pancotti, Vedika Saravanan and Krysta Svore
Accurate noise models are essential for high-performance
quantum error correction, yet characterizing the noise of a
quantum device typically requires dedicated experiments. We present a variational framework that learns the noise model directly from
quantum-error-correction syndrome and logical-observable data collected during error-corrected
memory experiments. The fault-event probabilities are treated as variational parameters and optimized via gradient descent to minimize the binary cross-
entropy between the decoder's predictions and experimental logical-observable outcomes. We prove that this objective is principled rather than ad hoc: a sufficiently expressive noise ansatz attains the information-theoretic minimum logical error rate. We instantiate this framework using a tensor-network decoder, which provides exact maximum-likelihood decoding and analytically differentiable gradients with respect to all noise parameters. Using
circuit-level data from Google's Sycamore processor, and starting from an uninformed prior, the optimization recovers noise models whose logical error rates agree to within $2\%$ with those of Google's independently characterized detector error model. The mean squared error between the learned and reference noise parameters shows a clear overall decrease throughout training, confirming that the method recovers physically meaningful noise structure, not merely parameters that happen to decode well. We further demonstrate that the optimization can track device drifts in real time via warm-started updates, maintaining near-optimal decoding performance under synthetically evolving noise without the need for re-characterization. The approach is decoder-agnostic in its formulation and naturally extends to correlated noise models.
Read the full abstract ▾
Quantum Physics
Entangling capability of coherently controlled quantum processes
Beyza Aslanbaş, Bedirhan Alkan and Göktuğ Karpat
We analytically characterize
entanglement generation by two paradigmatic coherently controlled
quantum processes, the
quantum switch and time-flip. Retaining rather than measuring or discarding the control, we treat the control and target as the bipartite system and assume pure product inputs, so that any output
entanglement reflects the entangling capability of the process. For the switch of
qubit unitaries, we derive exact expressions for
entanglement, together with a
geometric characterization and a coherence-
entanglement conservation relation. We then extend our analysis to binary random
unitary, Pauli, amplitude damping, and generalized amplitude damping channels. We prove that switch of channels commuting under composition cannot entangle a separable input. Yet maximal
entanglement is possible even with dissipation, e.g., an
entanglement-breaking damping channel switched with a bit-flip can transform a product input into a maximally entangled state. For two generalized amplitude damping channels, a common stationary state prevents
entanglement, while different stationary populations can enable it. We present an analogous study for the time-flip of
unitary and binary random
unitary channels. Our findings provide a systematic analysis of how much
entanglement can be generated by coherent control of channel order or input-output direction.
Read the full abstract ▾
Quantum Physics
Encoding Compact U(1) Gauge Fields in Bosonic Modes with GKP Stabilization
Victor Ale, Tommaso Rainaldi, Enrique Rico et al. (+2 more)
Compact
lattice gauge theories are formulated in terms of angular variables and integer electric fluxes, while bosonic
quantum hardware provides oscillator modes with continuous, unbounded quadratures. We bridge this gap with a one-to-one encoding. After Gauss's law is solved, each remaining gauge degree of freedom is carried by a single oscillator mode, with its interactions built from trigonometric gates, and a Gottesman–Kitaev–Preskill (GKP)-type stabilizer provides the compactness that the hardware does not. The encoding becomes exact in the limit of infinite squeezing, and at finite squeezing, the leading imperfections act as small, computable shifts of physical observables rather than uncontrolled leakage. We apply the construction to compact QED$_3$ and derive the error budget at finite squeezing, characterizing the leading errors in closed form, and showing that they can be corrected, subtracted, or extrapolated away. We construct syndrome-extraction protocols that detect and remove the displacement component of
photon loss, delimit the noise it does not reach, compare two choices of dynamical variables, and collect the scaling of mode count, gate count, and measurement cost. A one-plaquette example reproduces the exact compact-rotor dynamics, and real-time spectroscopy with controlled extrapolations recovers the exponentially small energy splitting between charge sectors, the seed of the monopole physics of the theory, at the percent level against its exact value.
Read the full abstract ▾
All authors Victor Ale, Tommaso Rainaldi, Enrique Rico, Felix Ringer, George Siopsis
High Energy Astrophysical Phenomena
Redshift Identifiability from Gamma-Ray Burst Prompt Emission
Shu-Xu Yi
We examine which
prompt-emission observables of gamma-ray bursts (GRBs) carry identifiable
redshift information in realistic structured-jet scenarios. By examining the
photon-level Lorentz and cosmological transformations, we demonstrate any spectral observable reflecting the dominant-patch emission and any temporal observable reflecting the co-moving frame physics in the jet suffers from the same $z$-$\theta_v$ degeneracy. The observable reflecting the absolute flux or count rate will also suffer from this $z$-$\theta_v$ degeneracy in a different form. Due to the large variation of the intrinsic luminosity, combining the observables in the above-mentioned three classes cannot break this degeneracy. However, we demonstrate that two other classes of observables contain the potential to break this degeneracy: (i)~central engine-imprinted time scales, (ii)~emission from out of the dominant patch.
Read the full abstract ▾
Statistical Mechanics
Exact joint eigenvalue densities of non-Hermitian random matrices are Calogero scattering states
Zhenyu Xiao, Ze Chen and Shinsei Ryu
Determining exact joint
eigenvalue densities is central to random
matrix theory. We solve this long-standing problem for non-Hermitian
matrices with transposition
symmetry (complex symmetric and complex self-dual) at arbitrary
matrix size. Up to a Vandermonde factor, they are scattering-state wave functions of the Calogero model, a line of particles interacting through an inverse-square potential, with the coupling strength set by the
symmetry. In contrast to many previously known joint densities, the densities cannot be written as a gas of
eigenvalues with pairwise interactions. We further compute the complex level spacing distributions and two-point spectral correlation functions, which carry power-law tails, absent in a Coulomb gas. Our results shed light on the interplay among random
matrices, integrability, and
symmetry.
Read the full abstract ▾
Statistical Mechanics
Duality between the level statistics of Hermitian and non-Hermitian random matrices
Ze Chen, Zhenyu Xiao, Yifei Liu et al. (+1 more)
The complex spectral statistics of non-Hermitian random
matrices provide a standard diagnostic of dissipative
quantum chaos. Yet an analytical understanding of how
symmetry enriches these universal correlations remains limited. We establish an exact duality between the spectral statistics of Hermitian and non-Hermitian random
matrices in the limit of large
matrix size. This duality resolves a longstanding analytical problem by yielding the previously unknown
eigenvalue pair-correlation functions for complex symmetric (class AI$^\dagger$) and complex self-dual
matrices (class AII$^\dagger$), completing the analytical description of bulk pair correlations in the non-Hermitian threefold way. It further gives closed-form spectral densities near the origin for seven additional
symmetry classes. Numerical tests in interacting and dissipative
quantum models support the universality of these predictions beyond Gaussian ensembles. The duality suggests a deeper connection between chaos in closed and open
quantum systems.
Read the full abstract ▾
All authors Ze Chen, Zhenyu Xiao, Yifei Liu, Shinsei Ryu
High Energy Physics (Theory)
Exploring thermal order in conformal theories with multiple scalars coupled to an $O(N)$ vector field
Soumyadeep Chaudhuri, Bilal Hawashin, Eliezer Rabinovici et al. (+1 more)
We study thermal order in conformal field theories (CFTs) in $d=4-\epsilon$ and $d=3$ dimensions where several scalars are coupled to an $O(N)$ vector field. In $(4-\epsilon)$ dimensions, we consider models coupling a cubic model of $M$ scalars with $\mathbb{Z}_2^M\rtimes S_M$
symmetry (corresponding to sign flips and permutations of the scalars) to an $O(N)$ vector model. For any $M$, we find a window of $N$ in which two Wilson-Fisher-like fixed points exist. We show that the $\mathbb{Z}_2^M\rtimes S_M$
symmetry is spontaneously broken at arbitrary nonzero temperatures for $M=2$ and sufficiently large $N$ within this window, but it remains unbroken for $M>2$. Using the functional renormalisation group to continue these fixed points towards three dimensions, we find that they collide and move into the complex plane well before reaching $d=3$, suggesting that their continuation to $d=3$ does not yield
unitary CFTs. We then work directly in three dimensions at large but finite $N$, with $M\ll N$, initially without assuming any permutation
symmetry among the $M$ scalars. By studying the RG flow, we show that these models possess a conformal
manifold up to the leading nontrivial order in the $1/N$ expansion of the beta functions (which is $\mathcal{O}(1/N)$). At each point on this
manifold, the scalars split into two classes that are distinguished by how they couple to the $O(N)$ vector field. We then restrict to a subspace of the conformal
manifold where there is an additional
symmetry under permutations of the scalars within each class. We prove that in a domain of this subspace, all $M$ scalars acquire thermal expectation values such that the
symmetry under sign flips of the scalars is spontaneously broken at all nonzero temperatures. This provides a novel class of large $N$ CFTs that exhibit a rich pattern of persistent
symmetry breaking at nonzero temperatures.
Read the full abstract ▾
All authors Soumyadeep Chaudhuri, Bilal Hawashin, Eliezer Rabinovici, Michael M. Scherer
Statistical Mechanics
Nonlinear Fluctuating Hydrodynamics from Interacting Noisy Quantum Matter
Alexios Christopoulos, João Costa, Stefano Scopa et al. (+4 more)
A universal characterization of non-
equilibrium steady states in interacting
quantum many-body systems remains one of the central challenges of statistical physics. Here, we address this problem for a paradigmatic model of diffusive interacting
quantum matter—the boundary-driven XXZ
spin chain with bulk dephasing—and derive, directly from its microscopic Lindblad dynamics, an emergent classical Macroscopic Fluctuation Theory (MFT) governing its large-scale fluctuations. Crucially, the resulting hydrodynamics carries a density-dependent diffusivity and mobility as the fingerprint of interactions. This effective description enables the exact computation of the stationary density profile, long-range correlations, and the full counting statistics of the current, in excellent agreement with tensor-network simulations. Our work demonstrates that noisy
quantum many-body systems can realize the universality class of genuinely interacting diffusive matter, beyond the constant-diffusivity class of the symmetric simple exclusion process, and establishes MFT as a powerful universal framework for interacting diffusive
quantum systems.
Read the full abstract ▾
All authors Alexios Christopoulos, João Costa, Stefano Scopa, Jacopo De Nardis, Zala Lenarčič, Denis Bernard, Tony Jin
General Relativity and Quantum Cosmology
Guiding center quantization of a quantum Hall analog of Hawking radiation
Rodrigo Andrade e Silva and Ted Jacobson
We revisit the
quantum Hall analog of Hawking radiation in which a
Fermi sea of electrons occupying half of a plane, subjected to a quadrupolar electric potential, gives rise to analog Hawking radiation of
chiral edge modes. We show that the phenomenon is accurately captured by quantization of the classical guiding center theory, where the gyroscopic motion of the electrons is coarse grained and only the drift motion is resolved. The
quantum dynamics takes place on a non-commutative plane, which requires an electron localized in the half-plane to be supported everywhere along the edge direction. This kinematical constraint on the
quantum state leads directly to the radiation, which propagates in both directions away from the origin along the edge. The radiation is thermal with respect to laboratory time, which is equal (up to a constant factor) to the boost angle in the analog Minkowski spacetime in which the
chiral edge modes propagate, so in fact it corresponds to analog Unruh radiation.
Read the full abstract ▾
High Energy Physics (Phenomenology)
Magnetic field-induced enhancement and quenching of Urca emission in quark matter
William Gyory and Igor A. Shovkovy
Using first-principles field-theoretic methods, we investigate
neutrino emission from strongly magnetized dense
quark matter under conditions relevant to compact
stars. We account for Landau-level quantization of both electron and
quark states and show that it strongly modifies the kinematics of Urca processes. In particular,
quark quantization restricts the available phase space in which both
quark and electron energies can simultaneously lie near their respective
Fermi surfaces. At moderately strong
magnetic fields, before pronounced
quark quantization sets in, the emission rate tends to increase on average with increasing field strength. In the regime of very strong fields, however, the increasingly restricted phase space first gives rise to Shubnikov–de Haas-type oscillations and then to resonance-like spikes near a discrete sequence of Urca-resonant
magnetic field values, separated by regions of strong suppression. Finally, the emission rate becomes nearly completely quenched once $|eB| \gtrsim 6\mu_{e}\mu_{u}$, corresponding to approximately $B\gtrsim 1.5\times 10^{19}~\mbox{G}$ for the representative set of model parameters considered. We also find significant anisotropy in the longitudinal momentum emission near the Urca-resonant
magnetic field values.
Read the full abstract ▾
Cosmology and Nongalactic Astrophysics
Extended radio emission in and around the merging cluster A520 as seen by MeerKAT
S. Giacintucci, W. D. Cotton, M. Markevitch et al. (+3 more)
We present results from a deep MeerKAT 1.28 GHz observation of Abell 520, a
galaxy cluster in the middle of a merger and a treasure trove of merger-generated phenomena. MeerKAT's combination of high angular resolution and sensitivity to extended
radio emission lets us uncover unprecedented detail of the cluster's
giant halo and puzzling features beyond the
halo. We find that the main
radio halo is sharply bounded along the direction of the NE-SW merger axis by the two X-ray shock fronts. In the perpendicular direction, the
halo wings smoothly span over 2 Mpc, with the spectrum steepening in the outskirts. We detect faint
radio emission upstream of the main (SW) bow shock; the emissivity jump across this shock can be used to constrain the physical mechanisms at work there. We discover a tail of
radio emission extending past the NE shock to the gas-poor, high-
entropy “dark subcluster” in the NE outskirts. The tail and subcluster have a higher
radio/X-ray brightness ratio than the main
halo's, suggesting efficient reacceleration of
cosmic rays. We also discover two peripheral
radio relics beyond the cluster virial radius, and a faint, $\sim2$ Mpc long, broad
radio bridge connecting the dark subcluster to one of the relics along the direction perpendicular to the merger axis. The spectral slopes of the dark subcluster and the bridge are consistent with that of the main
halo. This bridge and both relics may be caused by another
giant merger-generated shock front at the virial radius.
Read the full abstract ▾
All authors S. Giacintucci, W. D. Cotton, M. Markevitch, T. Venturi, T. E. Clarke, H. Bourdin
Instrumentation and Methods for Astrophysics
The promise of self-supervised and active learning for Strong Lens discovery: Astronomaly applied to KiDS
Margherita Grespan, Aprajita Verma, Michelle Lochner et al. (+3 more)
Strong gravitational lenses (SGLs) are rare systems whose discovery currently relies primarily on supervised machine learning methods trained on large simulated
datasets. We present the first application of Astronomaly:PROTEGE to SGL discovery, demonstrating that a human-in-the-loop active learning framework can efficiently identify lenses in large imaging surveys without the need for simulated training data. We consider a sample of 3.7 million bright
galaxies from the Kilo-Degree Survey (KiDS) DR4. Feature representations are extracted using a convolutional neural network pre-trained on the ImageNet
dataset and subsequently fine-tuned on KiDS data using the self-supervised Bootstrap Your Own Latent (BYOL) framework. Within the
embedding of these representations, the active learning loop of Astronomaly iteratively selects the most informative systems for expert inspection. A total of 3,000 objects are inspected across multiple rounds, yielding 34 high-quality (grade A/B) SGL candidates. On the basis that these systems occupy similar regions in the learned feature space, we expand this sample through nearest-neighbour similarity analysis. Including the active learning discoveries, we identify a total of 140 grade A/B candidates and more than 1,000 additional lower-confidence systems (grade C). Among the A/B candidates, 81 are newly identified, while approximately 22% of previously known grade A/B KiDS lenses are recovered. These results demonstrate strong potential for next-generation surveys such as Euclid, Roman, and Rubin's Legacy Survey of Space and Time. With approximately 60% of the high-quality candidates newly reported, this approach complements supervised methods by reducing reliance on simulations and enabling the discovery of a diverse population of SGLs.
Read the full abstract ▾
All authors Margherita Grespan, Aprajita Verma, Michelle Lochner, Koketso Mohale, Verlon Etsebeth, Duncan Bowden
High Energy Physics (Theory)
Subleading Collinear Limits of Yang-Mills Amplitudes from Gravity
Jin Dong and Stephan Stieberger
We show that the subleading collinear sector of Yang-Mills (YM) amplitudes is controlled by ordinary Einstein-Yang-Mills (EYM) amplitudes and their higher-derivative corrections. The complete set of strict subleading collinear limits associated with an equal-helicity collinear pair can be extracted from open-closed string disk amplitudes. The latter generate $\frac12 (n-3)!$ BCJ-like relations with non-linear kinematic coefficients, reducing the $(n-3)!$ collinear data to a basis of dimension $\frac12 (n-3)!$. This reduced basis can be represented by gravitational amplitudes in EYM theories and by their higher-derivative open-string corrections. At multiplicity $n$ this gravitational basis consists of the $(n-4)!$ independent EYM subamplitudes together with $\frac12 (n-5)(n-4)!$ higher-order corrections involving one graviton and $n-2$
gluons. The resulting decomposition is governed by unsigned Stirling numbers of the first kind: the ordinary EYM amplitudes correspond to the sector $\left[{n-3\atop 1}\right]$, the higher-order BCJ-like relations to even sectors $\left[{n-3\atop 2j}\right]$, and the higher-derivative EYM corrections to odd sectors $\left[{n-3\atop 2j+1}\right]$ with $j\geq 1$.
Read the full abstract ▾
High Energy Physics (Experiment)
Proposing GRENDEL: GalleRy ExperimeNt for Decays of Exotic LLPs at the LHC
Matthew Citron, Federico Redi and Ryan Schmitz
Long-lived particles are a generic prediction of Standard Model extensions that address the hierarchy problem, the origin of
neutrino masses, the
baryon asymmetry of the Universe, and the nature of dark matter. Despite the breadth of theoretical motivation, neutral long-lived particles in the GeV-scale mass range remain difficult to probe at the LHC main detectors, where trigger limitations and challenging backgrounds curtail sensitivity over a wide range of lifetimes. We propose GRENDEL (GalleRy ExperimeNt for Decays of Exotic LLPs), a dedicated detector to be installed in the PX56 drainage gallery at CMS Point 5. GRENDEL will exploit the substantial rock and concrete between the detector and LHC interaction point as passive shielding in addition to employing active background rejection. Located approximately 22 m above the interaction point and running largely transverse to the beam, GRENDEL will span around 110 m and cover the central region $|\eta| < 0.6$. GRENDEL will make use of extruded scintillator bars to achieve competitive sensitivity with other proposed detectors while requiring minimal infrastructure, and without the need for civil engineering. We present the physics case, detector concept, and projected sensitivities to heavy neutral
leptons, dark scalars, and
axion-like particles covering the $0.2-15$ GeV mass range with 3 $\mathrm{ab}^{-1}$ of HL-LHC data. The
benchmarks span the
neutrino, scalar, and
axion portals, with production through exotic
Higgs decays, $B$- and $D$-
meson decays, and $W/Z$ decays.
Read the full abstract ▾
Astrophysics of Galaxies
The Halo Gas of Local Spiral Galaxies and the Link to Gaseous Satellites
Yong Zheng, Jingyao Zhu, Ben Wertz et al. (+2 more)
Gaseous satellites orbiting massive host
galaxies experience gas stripping and may contribute additional gas to the hosts' circumgalactic medium (CGM). We identify a sample of 21 local spiral
galaxies ($<$15 Mpc) and characterize their gaseous satellite populations from existing HI surveys to investigate the connection between host
galaxy CGM and satellite gas content. Most of our spiral hosts have $\leq3$ gaseous satellites in their
halos with $M_{\rm HI}\gtrsim10^{7}~M_\odot$. Using 26 HST/COS QSO sightlines at impact parameters of 0.1–0.9 $R_{\rm 200c}$, we find that the CGM of $z\sim0$ spiral
galaxies show large intrinsic scatters ($\sim1-2$ dex) in ion column densities and harbor a total cool gas mass of $2.5^{+7.5}_{\rm -1.9}\times10^9~(0.3Z_\odot/Z')~M_\odot$, largely consistent with their $z\sim0.2$ counterparts (e.g., COS-
Halos). Splitting our sample by the presence of gaseous satellites, we find that
galaxy hosts with gaseous satellites have higher detection rates (up to 50%) in metal ion absorbers, including OI, AlII, CII, SiII, SiIII, and SiIV, possibly because their CGM is more metal enriched or has more ionized gas in the cool phase. However, the CGM column densities show no significant correlation with either the number of gaseous satellites or their total HI masses, suggesting that the contribution from the gaseous satellites to the host CGM is likely small compared to the intrinsic scatters in the CGM profiles, and the profile trends are mainly influenced by sightlines' proximity to the hosts. The CGM detection rate becomes elevated when a sightline is within half the virial radius of a massive gaseous satellite (LMC-like or higher mass), likely due to stripped debris.
Read the full abstract ▾
All authors Yong Zheng, Jingyao Zhu, Ben Wertz, Yakov Faerman, Mary E. Putman
High Energy Physics (Theory)
On the mass spectrum of Viel-dreibein gravity
Eloy Ayón-Beato and Elizabeth Rodríguez Querts
We study the AdS-wave configurations of Viel-dreibein
gravity, a three-dimensional theory of $N$ interacting
spin-2 fields, as a pretext to characterize the mass spectrum of this multigravity theory. We manage to implement the known strategy of rewriting the system as a higher-derivative theory for a single dreibein, thereby deriving the precise $2N$th-order equation governing the dynamics of the AdS-wave profile in question. The second novelty we introduce is a factorization of such an equation as the product of $N$ Klein-Gordon operators, exploiting the recent representation of the roots of any $N$th-degree
polynomial in terms of the increasingly celebrated $\mathscr{A}$-hypergeometric functions. Remarkably, this allows us to determine the mass spectrum of the full theory independently of the number of involved gravities, which is essential for an explicit construction of the AdS-wave solutions. This enables us to explore the parameter space of the theory and find all its critical points (not only the Breitenlohner-Freedman bounds) where a much wider range of degeneracies in the squared masses arises. At those points, the solutions allow a zoo of new logarithmic modes leading to several $\log^{\chi-1}$ asymptotic behaviors, with $\chi\le N$, a signature of the existence of allegedly dual logarithmic conformal field theories.
Read the full abstract ▾
Earth and Planetary Astrophysics
Self-induced edge rings in protoplanetary disks
Massimiliano Bolchini, Haochang Jiang and Jiaqing Bi
Observations with a high angular resolution by ALMA have revealed that substructures are ubiquitous in protoplanetary disks. Axisymmetric
dust rings are the most common morphology. The profiles of some observed disks, including young disks, are smooth overall, with a localized dip or bump near the outer edge of the continuum disk that manifests as an edge ring. While embedded
planets might contribute to these structures, their physical origin remains unclear. We investigated the possibility that these edge rings arise purely from radiative transfer effects at the outer edge of a protoplanetary disk. A steep surface density
dust gradient at the outer edge of the disk allows
stellar irradiation to penetrate more efficiently beyond the disk edge, producing a non-monotonic temperature profile characterized by a dip that is followed by a bump. We tested whether this non-monotonic temperature structure can generate and maintain a localized continuum enhancement. We coupled radiative transfer and
dust evolution by iterating between the Monte Carlo radiative transfer code RADMC-3D and the
dust evolution code DustPy. This framework self-consistently follows the coupled
evolution of temperature, grain growth, and
dust dynamics. Thermodynamic feedback at the disk edge can naturally generate and maintain localized
dust enhancements resembling the edge rings that are observed in some extremely young disks. Without invoking
planets or additional dynamical perturbations, this mechanism offers a plausible explanation for the first-generation ring formation. Our results highlight the importance of coupling thermodynamics and
dust evolution when modeling protoplanetary disks, suggesting that thermodynamic feedback probably plays a role in shaping disk substructures.
Read the full abstract ▾
High Energy Physics (Theory)
Regulating Free-scalar and Yang–Lee 5d CFTs on the Fuzzy Four Sphere
Jiangyuan Qian
Non-commutative sphere regularization of CFT has become a powerful tool for computing conformal data of 3d CFTs and was recently extended to 4d CFTs. In this work we further construct 5d free-scalar CFT and Yang-Lee CFT on a fuzzy 4-sphere. We observe a continuous phase transition and conformal towers in these examples. We obtain the first three scalar primaries of the 5d free-scalar CFT, furthermore, we compute the 5d Yang-Lee $\Delta_\phi,\Delta_{\phi^3}$ with $N_e=10$
fermions using exact diagonalization (ED) and $N_e=20$
fermions using density
matrix renormalization group (DMRG), obtaining relatively good agreement with both $\epsilon$-expansion and the Gliozzi truncated bootstrap result.
Read the full abstract ▾
Earth and Planetary Astrophysics
The Venus Benchmark: Resolving Degeneracies in Terrestrial Exoplanet Spectra with DAVINCI
Stephen R. Kane, David S. Alexander, Shahid Aslam et al. (+8 more)
The characterization of terrestrial
exoplanets with thick, CO$_2$-dominated atmospheres via transmission and emission spectroscopy is limited by degeneracies between atmospheric composition, cloud structure, and surface conditions. These degeneracies are particularly acute for
planets in or near the Venus Zone, where sulfuric acid aerosol layers and deep-atmosphere opacity render the lower atmosphere and surface spectroscopically inaccessible via many optical/IR wavelengths. Venus provides the only accessible analog to such worlds, yet current knowledge of its full atmospheric profile relies on decades-old in situ data with known limitations. Here we demonstrate that the forthcoming DAVINCI (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging) mission will provide the comprehensive, high-fidelity atmospheric profile data necessary to resolve many of these degeneracies. We quantify how atmospheric profile uncertainties translate into uncertainties in modeled transmission and thermal emission spectra of CO$_2$-dominated terrestrial worlds, and show that the spread in the modeled Venus
benchmark spectrum arising from current atmospheric profile uncertainties will decrease by factors of $\sim$4–5 for transmission and $\sim$5–15$\times$ for thermal emission after DAVINCI, providing a correspondingly improved
benchmark and prior for the modeling of
exoplanets with Venus-like atmospheres. We further demonstrate that these improvement factors are larger for the cloud-free atmospheric case, where the opacity floor is set by gas-phase processes rather than aerosols, because the pre-DAVINCI data are most discrepant in the sub-cloud region. Our results highlight the importance of Venus for the atmospheric characterization of rocky
exoplanets in the JWST and HWO era, and demonstrate how DAVINCI measurements will directly improve
exoplanet atmospheric modeling.
Read the full abstract ▾
All authors Stephen R. Kane, David S. Alexander, Shahid Aslam, Giada N. Arney, James B. Garvin, Stephanie A. Getty, Amy E. Hofmann, Noam R. Izenberg, Natasha M. Johnson, Erika Kohler, Emma L. Miles
Mesoscale and Nanoscale Physics
How Landau caterpillars turn into Hofstadter butterflies by tuning the periodic potential strength
Ivo A. Gabrovski and Louk Rademaker
It is well-known that the spectrum of two-dimensional electrons in a perpendicular
magnetic field is given by discrete flat Landau levels. By contrast, electrons in a two-dimensional tight-binding model give rise to a fractal Hofstadter butterfly spectrum. In this paper, we connect these two opposite limits by showing how a butterfly spectrum emerges from broadened Landau `caterpillars', by continuously increasing the periodic potential strength. We identify a series of topological transitions that isolate a lowest trivial band, a necessary condition for the butterfly to emerge. The resulting butterfly is topologically distinct from the Hofstadter butterfly at fluxes $\phi>1$, due to anomalous behavior of diagonal hopping. Moreover, the hopping parameters of an effective tight-binding model, obtained by a Wannierization procedure at large
magnetic field, are highly dependent on the flux, revealing that Wannier orbitals themselves change under the applied
magnetic field. Our methods and results are relevant for artificial materials, such as moiré systems, where a full
quantum of flux per
lattice unit
cell is experimentally accessible. On a theoretical level, having Wannierization methods for each specific flux allows more accurate many-body calculations in large
magnetic fields.
Read the full abstract ▾
Materials Science
Size-Dependent Growth Rates Amplify Infinitesimal Asymmetry in Nanocrystals
Sam Oaks-Leaf and David T. Limmer
The kinetic Wulff construction predicts symmetric nonequilibrium shapes when crystallographically equivalent facets share a fixed growth rate. However, nanocrystals grow through finite facets whose nucleation barriers and ligand coverages depend on facet size. Here we develop a size-dependent kinetic construction and show that as a consequence infinitesimal seed asymmetries can be amplified into strongly asymmetric nanocrystal morphologies even when all
symmetry-related facets obey the same microscopic growth law. Spatially heterogeneous nucleation rates and boundary limited growth generate facet growth velocities that depend on size, and deterministic shape
evolution translates these local rates into global shape
symmetry breaking. We illustrate the mechanism of persistent anisotropic growth on square and triangular
lattices in two dimensions and on FCC seeds in three dimensions, where cuboctahedra can evolve toward rods or tetrahedra depending on which facet-area perturbations are amplified.
Read the full abstract ▾
Statistical Mechanics
Bayesian Tracking of a Diffusing Target in Two and Three Dimensions
Ewan McCulloch and Adam Nahum
We study
Bayesian tracking of a diffusing target monitored by a noisy distributed sensor array. Building on an earlier mapping to KPZ growth with a moving defect (or an equivalent directed
polymer pinning problem) we determine the phase structure, beyond the previously-studied one-dimensional case, for both Bayes-optimal and suboptimal inference. In $d=2$, theoretical analysis and numerical simulations both give a depinning transition between a successful tracking phase and a failure phase. Weak-coupling RG shows that Bayes-optimal tracking is always successful in $d=2$, but failure can arise from overconfident (suboptimal) inference. In $d=3$, tracking can succeed, or can fail in two distinct ways: the posterior probability distribution may delocalize (no detection), or may become sharply localized, but at the wrong position (a false detection). The two possibilities correspond to Edwards-Wilkinson or Kardar-Parisi-Zhang statistics for the log-posterior. The three phases meet at a Nishimori-like multicritical point on a Bayes-optimal line in a two-parameter phase diagram. (Model misspecification alone can drive depinning into either unpinned phase: underconfidence gives diffuse failure, while overconfidence gives localized-but-wrong failure.) We analyze the transitions between the various phases numerically and with renormalization group arguments. We show that some of these have unusual critical behavior, which the conventional $\epsilon$ expansion fails to describe. Recent rigorous results for directed
polymers indicate an alternative scenario. Many of our results, including a scaling relation for exponents at pinning transitions and results for RG flows, are relevant to other phase transitions that involve surface growth or directed
polymers in 2+1D or 3+1D.
Read the full abstract ▾
Superconductivity
Subgap Bound States from Dynamical Impurities
Joshuah T. Heath
We find that a single non-
magnetic dynamical
impurity (e.g., a low-frequency localized "vibron" mode) induces a subgap bound state in an s-wave
superconductor. A closed-form solution for the bound state energy is found as a function of the vibron frequency in the elastic scattering limit, with the salient features of the bound state energies unaffected by inelastic scattering processes in the sub-THz regime. In addition to subgap features in the low-frequency local density of states, such
impurities result in real space regions of reduced spectroscopic weight outside the gap peak.
Read the full abstract ▾
Materials Science
Magnetic frustration and non-collinear textures in layered Gd magnets
Vladislav Borisov, Rohit Pathak, Sagar Sarkar et al. (+2 more)
Using scale-bridging simulations based on electronic structure theory and atomistic
spin dynamics, we investigate the
magnetic properties of skyrmionic GdRu$_2$Si$_2$ and GdRu$_2$Ge$_2$ layered rare-earth magnets and similar Gd-based compounds (GdAu$_2$Si$_2$, GdAu$_2$Ge$_2$, GdAg$_2$Si$_2$ and GdAg$_2$Ge$_2$). By studying the trends across this structural family, we confirm the importance of
magnetic frustration and dipolar interactions for the stability of non-collinear and skyrmion phases. Furthermore, our calculations predict promising opportunities for chemical tuning of these magnets in terms of the balance between various exchange interactions and the character of the
magnetic anisotropy. These changes lead to the formation of new types of skyrmions that are stable in a wide range of applied external
magnetic field. In particular, we propose partial alkali-metal substitution of Gd in GdRu$_2$Si$_2$ leading to GdKRu$_4$Si$_4$, GdRbRu$_4$Si$_4$, GdCsRu$_4$Si$_4$ as well as GdYRu$_4$Si$_4$ compounds, and suggest that it is likely to result in an ordered layered structure, similarly to previously reported iron pnictides like CaKFe$_4$As$_4$.
Read the full abstract ▾
All authors Vladislav Borisov, Rohit Pathak, Sagar Sarkar, Anna Delin, Olle Eriksson
Earth and Planetary Astrophysics
Using Ringed Disks to Determine Fundamental Parameters of Planet Formation
Olivia Wu, Luca Camarra and Eve J. Lee
Two non-dimensional parameters, Stokes number (St) and turbulent $\alpha$, critically control the early stage of
planet formation. In spite of their importance, these two numbers are notoriously difficult to obtain and remain largely unconstrained, except in ringed disks. In particular, E. J. Lee (2024) showed that ringed disks can be uniquely leveraged to derive local St and $\alpha$ through a simple model combining
dust radial equation of motion with the measured distribution of
dust masses in Class 0/I disks. We apply their model to the currently known census of ringed disks, finding 19 viable rings in 10 systems, which more than doubles the previous sample. Similar to previous findings, we obtain generally low St$\sim 10^{-4}$–$10^{-2}$ and $\alpha \sim 10^{-5}$–10$^{-2}$ across a wide range of system parameters, consistent with all the disks that we study to be rich in gas and the
dust-to-gas ratio of the rings to be too low to generate planetesimals. Disks around low mass host
stars likely have leakier traps, broadly consistent with massive, gap-carving
giants to be rare around low mass hosts, if the rings are generated by
planets.
Read the full abstract ▾
Strongly Correlated Electrons
Higher-Winding Fractionalization
Kishore Iyer, Christophe Mora and Daniele Guerci
Higher-winding skyrmion textures can generate emergent
magnetic fields with multiple flux quanta per unit
cell. This opens an intriguing route toward fractionalization, allowing fractionalized
quantum anomalous
Hall states to arise even at integer filling of the microscopic unit
cell. We show that, in this setting, increasing
lattice-scale inhomogeneity of the emergent
magnetic field drives a Berezinskii–Kosterlitz–Thouless (BKT) transition between a fractionalized
liquid and a crystalline dielectric state. This transition carries a topological signature: under flux insertion, the many-body polarization defines a quantized winding number that is nonzero in the fractionalized phase and vanishes in the dielectric
crystal.
Read the full abstract ▾
Atomic Physics
Collective dressed states for inelastic light scattering by atomic ensembles
Sébastien Lucas, David Wilkowski, Christian Miniatura et al. (+1 more)
We develop a general dressed-state framework for computing fluorescence spectra, probe absorption spectra, and
photon-
photon correlations of light scattered by ensembles of $N_\mathrm{at}$ two-level atoms with arbitrary $J_g \to J_e$ transitions driven by intense coherent fields. The approach employs a full vectorial treatment of the electromagnetic field, handles any atomic geometries, illumination directions, and polarizations, and yields optical observables as explicit sums of Lorentzian lines whose positions, widths, and weights are directly tied to the
eigenvalues and eigenvectors of the Lindbladian. The framework is implemented in an open-source Python package and benchmarked against exact single- and two-atom calculations. We identify geometries in which the full vectorial description is essential, and the scalar approximation fails qualitatively. Applying the method to pairs of atoms with a $J_g=0\to J_e=1$ transition, we show that elastic and inelastic scattered intensities collapse onto universal master curves controlled by a single collective saturation parameter built from the dominant superradiant mode, across several orders of magnitude in drive strength and interatomic distance. We identify collective phenomena that require a description beyond this single-mode picture. Extending the analysis to atoms with ground-state degeneracy, we find that most collective features carry over, while two qualitatively new effects emerge: an incoherent spontaneous Raman channel that modifies the scaling of inelastic emission, and a slow timescale in the time-delayed correlations $g^{(2)}(\tau)$ governed by the competition between Raman scattering and subradiant decay, controlled by a single dimensionless parameter. These results provide both physical insight and practical computational tools for engineering collective optical responses in few-atom systems such as optical tweezer arrays.
Read the full abstract ▾
All authors Sébastien Lucas, David Wilkowski, Christian Miniatura, Sergey E. Skipetrov
Solar and Stellar Astrophysics
Conspicuous Gas, Cryptic Dust: Spectroscopy and Chromaticity of Complex Periodic Variables
Luke G. Bouma, Facundo Perez Paolino, Lynne A. Hillenbrand et al. (+17 more)
Complex periodic variables (CPVs) are young low-mass
stars whose light curves show periodic dips indicative of transiting corotating material. The origin and composition of this material are unclear. Here we present new optical and near-infrared spectroscopy and photometry of four CPVs from Magellan, Keck, Hale, MuSCAT1, MuSCAT2, Tierras, KeplerCam, and TESS. The spectra imply that CPVs host magnetically bound circumstellar
plasma clumps, on the basis of sinusoidal-in-time Balmer emission out of transit, and Balmer dimming during transit. Yet large night-to-night changes in circumstellar hydrogen emissivity occur without clear changes in light curve morphology, suggesting that the sharp flux dips are caused not by circumstellar
plasma but by
dust. Optical chromaticities (depth proportional to $\lambda^{-\beta}$, with $\beta$ = 0.79 $\pm$ 0.16) support this, but the power law breaks in the near-infrared, where a single power law under-predicts the depths observed at 2.1 microns. We therefore favor dips caused by dusty
plasma clumps with opaque cores and optically thin
halos, though we cannot rule out models in which the
dust properties vary per-
star or per-epoch. Observations at wavelengths greater than 2 microns and less than 0.4 microns would test this interpretation and clarify the
dust's origin.
Read the full abstract ▾
All authors Luke G. Bouma, Facundo Perez Paolino, Lynne A. Hillenbrand, Juliana Garcia-Mejia, Allyson Bieryla, Patrick Tamburo, David Charbonneau, John H. Livingston, Keisuke Isogai, Norio Narita, Akihiko Fukui, Enric Palle, Felipe Murgas, Adolfo S. Carvalho, Howard Isaacson, Jessica J. Spake, Luisa M. Rebull, Moira M. Jardine, David R. Ciardi, Jeff A. Valenti
Astrophysics of Galaxies
ACES VII. Compact Continuum Source Catalog of the Central Molecular Zone
Jennifer Wallace, Cara Battersby, Nazar Budaiev et al. (+58 more)
The Central Molecular Zone (CMZ) resides in the inner few hundred parsecs of our
Galaxy, and despite being the largest reservoir of dense molecular gas in the Milky Way, it has a relatively low present-day
star formation rate (SFR) of $\sim0.08~M_{\odot}~\text{yr}^{-1}$. Continuum and spectral line observations from the Atacama Large Millimeter/submillimeter Array (ALMA) CMZ Exploration Survey (ACES) provide the first full-coverage, high-resolution map of the inner 200 parsecs of the CMZ at 3 mm. In this paper we present the ACES catalog of compact continuum sources, the most complete catalog of potential sites of
star formation in the CMZ to date. Using an automated dendrogram-based source extraction procedure in combination with a by-eye morphological classification scheme, we produce a `full' catalog of 1735 detections in total. Additionally, we use spectral index measurements to generate a `filtered' catalog of 567 sources with minimal contamination from non-thermal filaments and extended free-free emission. We find that 359 ($\sim63\%$) of the filtered catalog sources are located at column densities $< 10^{23}$ cm$^{-2}$, outside of the densest molecular cloud regions, 195 of which have not been identified in previous surveys. After cross-referencing with various catalogs generated from data at different wavelengths, we consider it likely that many of these newly discovered detections are produced by pre/protostellar sources or compact HII regions.
Read the full abstract ▾
All authors Jennifer Wallace, Cara Battersby, Nazar Budaiev, H Perry Hatchfield, Ashley T. Barnes, Taehwa Yoo, Miriam G. Santa-Maria, Antonio Daley, Q. Daniel Wang, Anika Schmiedeke, Kaitlyn E. Sheriff, Jairo Armijos-Abendaño, Daniel Walker, Gwenllian Williams, Dani R. Lipman, Farideh Mazoochi, Natalie O. Butterfield, Francisco Nogueras-Lara, Yoshiaki Sofue, Ralf S. Klessen, Simon C. O. Glover, Katharina Immer, Savannah R. Gramze, Katarzyna M. Dutkowska, Rojita Buddhacharya, Laura Colzi, Ashley Lieber, Alyssa Bulatek, Michael Wieber, Pablo García, Denise Riquelme-Vásquez, Emad Alkhuja, Yue Hu, Dennis Perlot, Howard A. Smith, Victor M. Rivilla, Wenyu Jiao, Fengwei Xu, Jonathan D. Henshaw, Adam Ginsburg, Elisabeth A. C. Mills, Qizhou Zhang, Steven N. Longmore, Nguyen M. Khang, Galaxy Salo, Jakub Poznanski, Dylan Pare, Maya Petkova, Izaskun Jiménez-Serra, Xing Lu, Sergio Martin, Alvaro Sanchez-Monge, Bijas Najimudeen, Christoph Federrath, Tabassum S. Tanvir, Pei-Ying Hsieh, John Bally, Paul Ho, Mattia C. Sormani, Robin G. Tress, Jaime E. Pineda