Strongly Correlated Electrons
Perfect Born Sampling of Symmetric Thermal Tensor Network States
Jianxin Gao, Qiaoyi Li, Yuan Gao et al. (+5 more)
Accurate calculations of correlated
fermions at low temperatures constitute a major challenge in
quantum many-body physics, most notably in the studies of high-$T_c$ superconductivity and ultracold atom optical
lattices.
Stochastic sampling of tensor-network states offers a promising route to tackle this problem; however, existing schemes have long faced a fundamental dilemma—sampling efficiency and
symmetry acceleration cannot be achieved simultaneously. Here we propose a perfect Born sampling approach for thermal tensor networks, which performs importance sampling directly from the purified density
matrix via the Born rule and incorporates Abelian and non-Abelian
symmetries by sampling
symmetry quantum numbers. We
benchmark the method, realized as both
stochastic matrix product states (stoMPS) and
stochastic projected entangled pair states (stoPEPS), on large-scale
quantum lattice models. Using stoMPS, we accurately simulate the square-
lattice Hubbard model on cylinders up to width $W=10$, and study the triangular-
lattice Hubbard model down to $T/t = 1/64$. We reveal scalar
chiral order at half filling and kinetic ferromagnetism upon electron doping, with the latter directly compared to ultracold atom experiments. We further extend the stoMPS method to compute finite-temperature
quantum dynamics, as demonstrated by the optical conductivity of the Hubbard model. We showcase the generalization of stoPEPS on up to $20\times20$ square-
lattice quantum Ising model, where accurate results are obtained near its
quantum critical point. Our method combines high sampling efficiency with full
symmetry acceleration. The resulting state-of-the-art framework captures both
equilibrium and dynamical properties down to ultralow temperatures, thereby providing a powerful theoretical tool for correlated
quantum systems, particularly
fermion Hubbard
quantum gas microscopy.
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All authors Jianxin Gao, Qiaoyi Li, Yuan Gao, Chuanshu Xu, Guoliang Wu, Su Yi, Bin-Bin Chen, Wei Li
Geophysics
AutoCF: An Automated LLM-Assisted Ecosystem for Compound Flood Simulation, Evaluation, and Impact Attribution
Soheil Radfar, Faezeh Maghsoodifar, Ning Lin et al. (+1 more)
Compound coastal flooding (CCF) arises from interacting coastal, precipitation, and river processes, yet modeling workflows often separate simulation, evaluation, and impact analysis. We present AutoCF, an automated ecosystem integrating data harmonization, model construction, observational evaluation, exposure analysis, complete factorial driver attribution, and cross-platform execution. The automated Hurricane Harvey simulation achieves a median root mean square error of 0.147 m and correlation of 0.951 across eight observational gauges, and a correlation of 0.942 with 55 high-water marks. Maximum water-level fields from CPU and GPU implementations agree within 0.01 m for 98.8% of
cells. Attribution analysis shows that during Harvey, precipitation dominated building and population exposure, whereas coastal forcing becomes increasingly important for deep and persistent inundation. The introduced Driver Impact Shift metric further quantifies whether each driver contributed disproportionately to societal consequences relative to its flooded-area contribution. Overall, AutoCF provides a reproducible pathway from CCF model construction to evaluation and driver-specific impact interpretation.
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All authors Soheil Radfar, Faezeh Maghsoodifar, Ning Lin, Hamed Moftakhari
Earth and Planetary Astrophysics
A temperate sub-Neptune transiting the M4 Dwarf TOI-210 identified by NIRPS and TESS – Uncovering hidden M-dwarf planetary systems in the near-infrared
C. Cadieux, B. N. Skinner, F. Bouchy et al. (+63 more)
Super-Earths and sub-Neptunes dominate the
exoplanet population, yet their compositions, formation mechanisms, and capability of retaining atmospheres remain poorly understood. M-type
stars offer a unique opportunity to investigate these questions, thanks to their favorable
planet-to-
star radius and mass ratios and the diversity of planetary systems they host. We aim to characterise the planetary system of the M4
dwarf TOI-210, in which TESS during its primary mission identified one transiting
exoplanet candidate at $P= 9.01$ days. We combine multi-technique observations, including transits from 40 sectors of TESS and ground-based follow-up with LCOGT and ExTrA, and radial velocities (RV) from NIRPS obtained as part of its Guaranteed Time Observations program. These data were analysed using a
Bayesian framework to constrain
stellar, planetary, and orbital parameters. We confirm TOI-210 b, a temperate sub-Neptune ($T_{\rm eq} = 368 \pm 9$ K) with a mass of 6.75 $\pm$ 1.25 M$_{\oplus}$ and a radius of 2.234 $\pm$ 0.074 R$_{\oplus}$. Its bulk density implies a volatile-rich composition, either as an extended H/He atmosphere with mass fraction of approximately 1% (gas
dwarf), a substantial water reservoir comprising at least 29% of the mass (2$\sigma$ lower limit; water world), or a mixture of both. The NIRPS RVs show moderate evidence ($\Delta \ln Z = 5.9$) for at least one non-transiting
exoplanet interior to TOI-210 b. In a targeted search, we identify two Keplerian signals at 2.15 and 3.76 days, with minimum masses of 3.2 $\pm$ 0.8 M$_{\oplus}$ and 4.4 $\pm$ 1.0 M$_{\oplus}$, respectively, that provide a plausible explanation for the observed RV variations. If these signals are
planets, the absence of transits in the TESS photometry implies mutual inclinations with TOI-210 b above 2.3-3.5$^{\circ}$.
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All authors C. Cadieux, B. N. Skinner, F. Bouchy, E. D. Gillis, V. Bourrier, R. Doyon, L. Y. Messamah, B. L. Canto Martins, A. L'Heureux, Y. S. Messias, J. M. Almenara, A. K. Stefanov, X. Bonfils, K. A. Collins, H. M. Relles, C. Rodríguez, P.-A. Roy, A. Shporer, G. Srdoc, S. Taylor, C. Ziegler, R. Allart, K. Al Moulla, É. Artigau, F. Baron, S. C. C. Barros, F. Bélanger, B. Benneke, M. Bryan, T. Ciolak, R. Cloutier, N. J. Cook, N. B. Cowan, E. Cristo, L. Dang, J. R. De Medeiros, X. Delfosse, E. Delgado-Mena, X. Dumusque, D. Ehrenreich, D. O. Fontinele, T. Forveille, J. Gagné, M. J. Hobson, P. Lamontagne, I. C. Leão, R. de Lima Gomes, C. Lovis, L. Malo, C. Melo, L. Mignon, C. Mordasini, N. Nari, L. Parc, R. Rebolo, R. Rosener, J. Rowe, N. C. Santos, D. Ségransan, A. Srivastava, A. Suárez Mascareño, S. Udry, D. Valencia, G. Wade, J. P. Wardenier, D. Weisserman
High Energy Physics (Phenomenology)
GAIA meets LZ: a high velocity tail-tale sign for dark matter
Anirban Das, Subhabrata Majumdar, Manibrata Sen et al. (+1 more)
The interpretation of high-energy
nuclear recoils in direct-detection experiments can depend sensitively on the high-velocity tail of the
galactic dark matter (DM) distribution. The LUX-ZEPLIN (LZ) experiment has recently reported an event, LZ230616, with
nuclear recoil energy 248 $\pm$ 23 (stat) $\pm$ 23 (sys) keV, while the
Gaia mission has provided an unprecedented view of the kinematics and mass distribution of the Milky Way. We bring these two probes together to investigate the inelastic DM interpretation of LZ230616, using a velocity distribution inferred from
Gaia-informed
galactic model. Compared to the Standard
Halo Model, the resulting distribution has a lower escape speed and a significantly suppressed high-velocity tail, with a higher local density. We find that while the exothermic interpretation is largely insensitive to this change, the endothermic interpretation requires substantially larger scattering cross sections and smaller mass splittings. Furthermore, using simulation-based study of the gravitational effects of the Large Magellanic Cloud, we show that the high-velocity tail can extend the allowed endothermic parameter space towards lower DM masses and larger splittings. Our results demonstrate how combining direct searches for DM detection with precision measurements of
galactic dynamics can qualitatively affect the particle-physics interpretation of high-energy
nuclear recoils.
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All authors Anirban Das, Subhabrata Majumdar, Manibrata Sen, Amogh Srivastav
High Energy Astrophysical Phenomena
Fast radio burst - persistent radio source systems III. The relation between PRS luminosity and FRB rotation measure
D. Pelliciari, G. Bernardi, L. Bruno et al. (+5 more)
Fast
radio bursts (FRBs) are millisecond-duration
radio transients of extragalactic origin whose physical origin remains uncertain. A small fraction of FRBs are known to repeat, and some of them are associated with persistent
radio sources (PRSs), interpreted as synchrotron-emitting nebulae surrounding the FRB source. In the context of magnetar-based models, the rotation measure (RM) of an FRB is expected to correlate with the spectral luminosity of its associated PRS, providing a probe of the physical properties and
evolution of the nebula. We investigate the relation between FRB RM and PRS spectral luminosity, constrain the characteristic size of the PRS nebulae, and use the intrinsic scatter of the relation to investigate evolutionary scenarios for FRB–PRS systems. We analyse a sample of 50 FRB sources with known RM, including both PRS detections and spectral luminosity upper limits, using a
Bayesian MCMC framework that jointly accounts for detections and non-detections. We model the luminosity–RM relation as $L_\nu \propto \zeta_e \gamma_c^2 R^2 {\rm RM}^\beta$, constraining the characteristic nebular size $R$ and the RM scaling index $\beta$. For the full sample, we obtain $R = 0.016^{+0.115}_{-0.014}$ pc at $1\sigma$ confidence for a free $\beta$, while fixing the RM dependence to the canonical linear scaling, $\beta = 1$, gives $R = 0.008^{+0.058}_{-0.007}$ pc. The data mildly favour super linear RM scalings, although the inferred values of $\beta$ remain consistent with $\beta = 1$ within $2\sigma$. We find a substantial intrinsic scatter in the luminosity–RM relation, significantly larger than previous estimates based on confirmed PRSs alone. Interpreting this scatter within evolutionary models, our results favour scenarios involving efficient particle acceleration and/or rapid nebular expansion.
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All authors D. Pelliciari, G. Bernardi, L. Bruno, M. Pilia, P. Esposito, L. Beduzzi, A. Geminardi, O. Smirnov
High Energy Astrophysical Phenomena
Fast radio burst - persistent radio source systems II. A faint PRS associated with the nearby FRB 20181030A?
D. Pelliciari, G. Bernardi, B. Margalit et al. (+10 more)
Persistent
radio sources (PRSs) are the continuum counterparts of fast
radio bursts (FRBs), the latter being extragalactic transients of millisecond duration and Jy-level flux density. An FRB-PRS system is thought to be a flaring magnetar surrounded by an highly magnetized,
baryon-loaded nebula. We aim to constrain the size of 20181030A-S1, a new PRS candidate, potentially associated with the repeating FRB 20181030A. The latter is localized with $\sim 1'$ uncertainties in the outskirts of NGC 3252, which is a spiral
galaxy at a luminosity distance of $20$ Mpc. We report very long baseline interferometric (VLBI) observations using the European VLBI Network at $1.7$ GHz of this PRS candidate at an angular resolution of $20$ milliarcseconds. Our observations reveal the presence of an unresolved
radio source (20181030A-S1) at the position of the PRS candidate, confirming its compactness at milli-arcsecond angular scales. A fit to the position of the point-source yields a peak flux density of $280 \pm 30$ $\mu$Jy and a transverse physical size constrained to be $R < 0.5$ pc at $68\%$ confidence level (CL). This flux density converts to a spectral luminosity of $(9 \pm 1) \times 10^{25}$ erg s$^{-1}$ Hz$^{-1}$, $\sim 3$ orders of magnitude lower than confirmed PRSs, making 20181030A-S1 the closest and faintest PRS candidate known. Its low luminosity and modest rotation measure are consistent with the $L_\nu-$rotation measure (RM) relation followed by confirmed FRB–PRS systems, supporting a common physical origin in magnetar-powered nebulae. We show how a magnetized wind nebula powered by an initially weak ($B_\star \simeq 10^{15}$ G) and young ($t_{\rm age} \simeq 15 - 150$ yrs) magnetar can account for both the observed spectral luminosity and RM of the system. Other possible origin scenarios for 20181030A-S1, in the case in which it is unrelated to the FRB source, are also discussed.
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All authors D. Pelliciari, G. Bernardi, B. Margalit, B. D. Metzger, C. Nanci, L. Bruno, M. Pilia, L. Beduzzi, C. Spingola, C. Stanghellini, P. Esposito, A. Geminardi, M. Giroletti
High Energy Astrophysical Phenomena
Fast radio burst - persistent radio source systems I. A 1.2 GHz search and catalog definition
D. Pelliciari, L. Bruno, G. Bernardi et al. (+5 more)
We present new $1.26$ GHz observations of 24 fast
radio bursts (FRBs; 9 repeaters and 11 one-offs), conducted with the upgraded
Giant Meter Wave
Radio Telescope (uGMRT) at arc-second angular scale resolution, and combined them with literature data to construct an extended sample of 75 sources with either persistent luminosity measurements or upper limits. Our catalog is complete down to a $10^{29}$ erg s$^{-1}$ Hz$^{-1}$ luminosity threshold, which corresponds to the value of the first-discovered PRS, associated with FRB 20121102. We detect compact
radio emission in six FRB fields, two of which are previously known PRSs and four are new candidates. The four new candidates are associated with three new repeating FRBs and one apparently one-off source. We computed the PRS occurrence using the whole catalog of 75 FRBs and found that PRSs more luminous than $10^{29}$ erg s$^{-1}$ Hz$^{-1}$ are rare. Unless otherwise stated, all uncertainties and upper limits are reported at the $95\%$ confidence level (CL). If we only consider confirmed PRSs, we find an occurrence of $f_{\rm all} = 0.06^{+0.09}_{-0.03}$, while including PRS candidates as well yields $f_{\rm all} = 0.14^{+0.22}_{-0.08}$. We also compute the PRS occurrence in the two classes of FRBs: repeating and non-repeating. In the conservative case, i.e., when none of the new PRS candidates are considered to be associated with their FRBs, we find no preferred association between the PRSs and FRB class, with an occurrence of $f_{\rm r} = 0.14^{+0.20}_{-0.09}$ for the sample of repeating FRBs and $f_{\rm nr} \leq 0.12$ for the sample of one-off sources. In the inclusive case, i.e., when all the new candidates are considered confirmed PRSs, we find $f_{\rm r} = 0.27^{+0.21}_{-0.14}$ and $f_{\rm nr} = 0.03^{+0.14}_{-0.02}$, with marginal ($90\%$ CL) evidence that PRSs are preferably associated with repeating FRBs.
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All authors D. Pelliciari, L. Bruno, G. Bernardi, M. Pilia, P. Esposito, L. Beduzzi, A. Geminardi, O. Smirnov
High Energy Astrophysical Phenomena
Empirical determination of the Galactic neutron star–black hole merger rate using StarTrack models
Terrence Pierre Jacques, D. R. Lorimer, Nihan Pol et al. (+2 more)
The discovery of a
pulsar in a binary system with a black hole would provide a unique laboratory for testing general relativity in the strong-field regime and offer vital constraints on massive
star evolution. We assess prospects for the detectability of such systems by utilizing the
radio pulsar population and survey models within the modeling package PsrPopPy and, as a proof of principle, two evolutionary models with different treatments of common-envelope phases from the
stellar population synthesis code StarTrack. For these two models, assuming the
radio pulsar beaming model proposed by Tauris and Manchester and accounting for the effects of orbital motion on
pulsar detectability, we calculate upper limits on the number of
neutron star–black hole systems in the
Galaxy and the corresponding merger rate given the lack of any
radio-detected
pulsar–black hole binary systems in current
radio surveys. For the most constraining model, we find a
Galactic merger rate $< 4.3~\text{Myr}^{-1}$ (at 95% confidence). These results are extrapolated to the expected horizon distance for the fifth LIGO observing run, leading to LIGO detection rate estimates that are consistent with the latest values reported by the LIGO-Virgo-KAGRA collaboration. Our results indicate that the increased sensitivity of FAST, MeerKAT, and DSA offers the best prospects yet for uncovering this elusive population.
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All authors Terrence Pierre Jacques, D. R. Lorimer, Nihan Pol, M. A. McLaughlin, K. Belczynski
Lattice Field Theory
Multilevel Plaquette-Space Sampling for Lattice Gauge Theories with Local Constraint Solves
Ankur Singha, Jacob Finkenrath, Karl Jansen et al. (+2 more)
Lattice gauge theories are an important class of physical models with high-dimensional structured distributions that underpin first-principles calculations in particle,
nuclear, and condensed-matter physics. Recent advances in generative modeling have opened new avenues for sampling Boltzmann distributions in
lattice gauge theories, offering the potential to alleviate limitations of traditional Monte Carlo methods, including critical slowing down and topological freezing. However, generative samplers for
lattice gauge theories are typically constructed in link space, where correlations become increasingly long-ranged toward weak coupling, posing a challenge for learning. Plaquettes provide a more natural representation, as the action is local in these variables. However, exact Bianchi constraints restrict them to a lower-dimensional
manifold, complicating direct generative modeling. We introduce a multilevel normalizing-flow construction that samples directly in plaquette space while satisfying these constraints exactly. The key idea is a coarse-to fine factorization that transforms a globally coupled constraint problem into a sequence of local solves: at each refinement, every determined plaquette depends on at most four newly generated variables, while the size of the constraint problem remains independent of the
lattice size. We validate the construction for $U(1)$ in two and four dimensions and for $SU(2)$ in two dimensions. Our multilevel Plaquette-Space Sampler (PSS) substantially outperforms link-space baselines, with the advantage increasing toward weak coupling, where the gauge coupling becomes small. This regime is particularly challenging for generative sampling and, in asymptotically free gauge theories, is relevant to continuum studies.
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All authors Ankur Singha, Jacob Finkenrath, Karl Jansen, Vipul Arora, Shinichi Nakajima
Earth and Planetary Astrophysics
Correcting stellar contamination in transmission spectroscopy with contemporaneous monitoring: Application to GJ 1214 b
Ò. Porqueras-León, M. Perger, J. C. Morales et al. (+19 more)
Transmission spectroscopy has emerged as an essential tool for characterising the atmospheres of transiting
exoplanets. However,
stellar surface inhomogeneities contaminate transmission spectra, posing a major challenge to high-precision observations such as those from the James Webb Space
Telescope (JWST). We develop and apply methods to correct for
stellar contamination, improving the accuracy of
exoplanet atmospheric characterisation. We obtained coordinated multi-band photometry and high-resolution spectroscopy around JWST observations of GJ 1214 b and applied two frameworks: (i) a StarSim inversion, which infers
stellar activity parameters from the monitoring data and propagates them to corrections; and (ii) UnSPOTTER, in which neural networks trained on StarSim simulations learn the mapping from monitoring data to corrections. Both frameworks agree within uncertainties and indicate that the JWST observations of GJ 1214 occurred at a favourable rotation phase with low
stellar contamination. For UnSPOTTER, the inferred corrections can be constrained at approximately 15 ppm across the JWST wavelength range, implying post-correction residuals of the same order. If the same system were observed near activity maximum, the predicted contamination would be strongly chromatic and affect atmospheric
retrievals, highlighting the importance of coordinated monitoring and robust activity correction techniques. The two approaches are complementary but serve different roles. The inversion yields physically interpretable parameters and surface maps, whereas UnSPOTTER marginalises over surface-configuration degeneracies and provides tighter predictive corrections within its validated simulation domain. Our pipeline can be generalised to other active
stars: with multi-band and multi-technique monitoring around JWST visits, it can provide activity forecasts for scheduling and activity corrections.
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All authors Ò. Porqueras-León, M. Perger, J. C. Morales, I. Ribas, J. Blanco-Pozo, H. Tabernero, E. Herrero, E. Pallé, H. Parviainen, F. Murgas, C. Rodríguez-López, P. H. Hauschildt, A. Schweitzer, N.-E. Nèmec, D. Baroch, N. R. C. Gomes, G. Anglada-Escudé, J. Aceituno, N. Narita, A. Fukui, M. Mori, Y. Smolyarova
High Energy Astrophysical Phenomena
SN 2025qe: A case study of diversity in low-luminosity thermonuclear explosions
Hrishav Das, Anirban Dutta, Devendra K. Sahu et al. (+3 more)
We present optical photometric and spectroscopic observations of SN 2025qe, a Type Iax
supernova in IC 0529, monitored from $-10$ to $+150$ rest-frame days relative to $g'$-band maximum using the GROWTH-India and the Himalayan Chandra
Telescopes. SN 2025qe reaches a peak $g'$-band absolute magnitude of $M_{g'} \approx -16.16 \pm 0.15$ mag, placing it in the sparsely sampled luminosity gap between the brightest and faintest members of the SNe Iax class. The multiband light curves show pronounced wavelength-dependent broadening at late times, with the redder bands remaining brighter than in other SNe Iax. Semi-analytical (Arnett) modeling of the pseudobolometric light curve yields a synthesized $^{56}$Ni mass of $0.02\,M_\odot$, an ejecta mass of $0.45\,M_\odot$, and a kinetic energy of $7.0\times 10^{49}$ erg. Three-dimensional pure-deflagration models of Chandrasekhar-mass carbon-oxygen white
dwarfs reproduce the peak luminosity and $^{56}$Ni yield but underpredict the slow, red post-maximum decline; models including energy input from a bound remnant better match the late-time
evolution, especially in the red bands. We model early-time spectra using TARDIS with a modified deflagration model and identify late-time spectral features using syn++. We qualitatively try to explain the persistent red-band flux with a two-component ejecta structure comprising a dense inner region, possibly including a bound remnant, and a density-enhanced outer shell that sustains redder emission. Together, the photometric and spectroscopic properties of SN 2025qe highlight the diversity of ejecta structure and
evolution among SNe Iax with similar peak luminosities, emphasizing the need for detailed observations and modeling of their ejecta.
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All authors Hrishav Das, Anirban Dutta, Devendra K. Sahu, G.C. Anupama, Prathamesh S. Kadam, Vishwajeet Swain
Cosmology and Nongalactic Astrophysics
Tide-and-Seek: Anisotropic scale-dependent bias in the Lyman-alpha forest and designer samples
Yong Sheng Yap, William R. Coulton and Vid Iršič
Searches for
primordial non-Gaussianity are powerful ways of learning new information about the early Universe. Observing
primordial signals in the late Universe is challenging as, in general, it is difficult to disentangle the small,
primordial signatures from the complex physics that describes the distribution of
galaxies and large-scale
cosmic structures. We demonstrate that scale-dependent bias from
primordial non-Gaussianity with non-trivial directional dependence in the squeezed limit (also known as anisotropic
primordial non-Gaussianity) can arise in a much larger class of tracers than previously considered. This is a smoking gun signature of
primordial Universe physics that cannot be mimicked by late-Universe processes. We demonstrate this explicitly with simulations of the Lyman-$\alpha$ forest and
halos selected through their projected shape. The former is a standard cosmological probe and standard analyses could be simply extended to constrain this. The latter provides an interesting new approach: design samples with strong selection effects to provide new sensitivity to
primordial physics. As a demonstration of these concepts, we apply this method to BOSS DR12 data, finding no evidence of anisotropic non-Gaussianity.
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Materials Science
Catalogue of Collinear Magnetic Structures in Stoichiometric Materials
Liangliang Huang, Houhao Wang, Yuanze Song et al. (+3 more)
Magnetic materials persistently serve as a fertile platform for exploring novel
quantum emergent phenom ena and advancing information technologies. Reliably determining their
magnetic structures (MSs), which is essential for understanding their emergent
quantum properties, usually depends on experiments such as
neutron scattering. Here, noting that around half of the MSs in MAGNDATA (a database of experimentally determined MSs) are collinear, we adopt the
spin space groups (SSGs) to preset the candidate MSs for a given nonmagnetic
crystal structure to be collinear from the outset. On the other hand, more than 80% of the collinear magnets in MAGNDATA are subject to maximal subgroups of nonmagnetic groups which are collinear SSGs, and we then enumerate all collinear MSs formed at Wyckoff positions by the maximal collinear SSG subgroups of the 230 nonmagnetic space groups. With such exhaustive enumeration, we categorize all
symmetry-allowed collinear MSs for the 72,075 nonmagnetic stoichiometric structures in Inorganic
Crystal Structure Database, obtaining 365,639 collinear MSs. We then determine the ground-state SSG
symmetries of 7,824 collinear magnets among the 21,315 selected materials using first-principles calculations. These magnets then undergo a comprehensive topological classification combining SSGs and
magnetic space groups, outputting thousands of new
magnetic topological materials. The experimentally determined MSs in MAGNDATA represent the tip of the iceberg in our computational database of collinear magnets, expected to guide MS characterization by experimentalists and further investigation towards spintronics applications.
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All authors Liangliang Huang, Houhao Wang, Yuanze Song, Ruixi Pu, Xiangang Wan, Feng Tang
High Energy Physics (Theory)
Journey to the Center of a Black Hole
Vyshnav Mohan
An infalling two-point function of a scalar field in a three-dimensional BTZ black hole, with one operator inserted in the exterior and the other inserted along a timelike geodesic, diverges when the infalling insertion point reaches the black hole singularity. In the boundary description, this divergence is tied to the exchange of double-twist operators rather than to the multi-stress-tensor sector that encodes
curvature singularities in higher dimensions. We show that the inclusion of a tower of massive particles with Hagedorn growth gives rise to loop corrections that become important near the singularity, where they trigger a Hagedorn transition that renders the tree-level divergence untrustworthy. In the boundary theory, the corresponding tower of primary operators leads to a breakdown of the generalized free field description of the probe operator in the black hole state. In a large black hole, these corrections become important only near the singularity and remain exponentially suppressed at the horizon. The region where these corrections dominate is therefore parametrically separated from the horizon, as anticipated by the principle of black hole complementarity.
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Materials Science
A Si-on-SiC Platform for Interfacing with Vanadium Dopants in the Telecom O-Band
Timothy Draher, Nolan Bitner, Vasileios Niaouris et al. (+6 more)
Vanadium color centers in silicon carbide (SiC) offer telecom O-band emission, sub-microsecond optical lifetimes, and second-scale
spin relaxation times, rendering them promising candidates for
quantum network nodes. However, efficient
photon extraction from the high-refractive-index SiC host remains challenging. Here, we introduce a silicon-on-SiC heterogeneous photonic platform in which silicon nanocavities evanescently couple to shallow vanadium dopants in commercial 4H-SiC, enabling efficient zero-
phonon line (ZPL) collection under resonant excitation. In as-grown ensembles, we observe Purcell-enhanced photoluminescence with transient spectral hole burning linewidths of 50 MHz on microsecond timescales. In dilute implanted samples, we isolate individual vanadium centers with high-purity single
photon emission and a Purcell-enhanced lifetime of 109 ns. The entire optical interface operates through a single lensed fiber, including a 905 nm repump
laser that recovers the vanadium charge state with 95% efficiency. These results establish Si-on-SiC as a scalable, foundry-compatible platform for telecom-wavelength
spin-
photon interfaces.
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All authors Timothy Draher, Nolan Bitner, Vasileios Niaouris, Claire E. McDermott, David Czaplewski, Supratik Guha, David D. Awschalom, F. Joseph Heremans, Alan M. Dibos
High Energy Astrophysical Phenomena
JWST unveils a dust-obscured supernova associated with a gamma-ray burst
B. Schneider, A. J. Levan, N. Sarin et al. (+22 more)
Recent observations have challenged the duration-based classification of gamma-ray bursts (GRBs), making the detection of an associated
supernova (SN) or kilonova crucial for conclusively identifying their progenitors. We investigate the origin of GRB 240825A at $z=0.659$, whose
prompt emission gave conflicting indications of a merger or collapsar origin and for which no SN was detected in deep ground-based observations. We analyze JWST/NIRSpec observations obtained 66.5 days (40.1 days in the rest frame) after the burst. We identify a SN signal using a pixel-by-pixel decomposition of the 2D spectrum and isolate it by jointly modeling the host and transient emission. We constrain the line of sight extinction from the afterglow spectral energy distribution and characterize the host through broadband photometry and nebular emission lines. Despite a dusty line of sight ($A_V=1.37\pm0.08$ mag), with tentative evidence of a 2175 Å bump, and a bright host
galaxy ($M_B=-20.5$ AB mag), we identify a point-like source at the GRB position with broad spectral features similar to those of SN 1998bw. The SN contributes $\sim$10-15% of the NIRSpec flux and would contribute only $\sim$1% of the total flux in a ground-based optical image at the same epoch. Its extinction-corrected luminosity is comparable to SN 1998bw, although it remains sensitive to the host subtraction and template assumptions. The host is an extended, dusty,
star-forming
galaxy with $\log(M_\star/M_\odot)=10.12\pm0.05$, SFR $=5.88\pm1.60\,{\rm M_\odot\,yr^{-1}}$, and a super-
solar metallicity of $12+\log({\rm O/H})=8.87\pm0.04$, above the
metallicity typically observed for collapsar GRB hosts. The detection of a
dust-obscured SN firmly establishes the massive-
star origin of GRB 240825A and shows that JWST can uncover SNe in dusty, chemically enriched environments that were previously largely inaccessible.
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All authors B. Schneider, A. J. Levan, N. Sarin, N. A. Rakotondrainibe, B. P. Gompertz, V. Buat, J. T. Palmerio, D. B. Malesani, A. de Ugarte Postigo, A. Martin-Carrillo, A. Rossi, V. D'Elia, M. De Pasquale, D. Hartmann, P. Jakobsson, E. Le Floc'h, P. O'Brien, E. Pian, G. Pugliese, A. Raidani, R. Salvaterra, J. Sollerman, N. R. Tanvir, S. D. Vergani, D. Watson
Quantum Gases
Structure and Dynamics of Bose Polarons across the Mott-Insulator to Superfluid Transition
Ragheed Alhyder, Alessio Recati and Georg M. Bruun
A mobile
impurity particle immersed in a
quantum degenerate gas leads to the formation of a quasiparticle, which can serve as a sensor for its environment. Here, we develop a unified wave function description of an
impurity in a two-dimensional Bose-Hubbard model across the Mott-
insulator to superfluid transition. Using a multi-mode variational ansatz based on the
quantum Gutzwiller approach, we show that the
impurity can form several kinds of polaronic and molecular states. In addition to their spectral properties, the wave function provides direct access to the microscopic structure of these states, and we demonstrate that strong correlations in the critical regime of the
quantum phase transition give rise to several non-analytic features in the polaron properties. Increasing the
impurity-
boson interaction leads to transitions between polaron and molecular ground states, and the number of
bosons in the
impurity dressing cloud grows rapidly at the
quantum critical point as the bath modes soften. We furthermore reveal qualitatively distinct non-
equilibrium many-body dynamics after the injection of the
impurity in the different phases of the Bose-Hubbard model. Our spectral, real space, and dynamical predictions describe complementary properties of polarons in a strongly correlated bosonic bath, which can be observed using current techniques with atoms in optical
lattices.
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High Energy Physics (Theory)
Microscopic Organization of BPS Black-Hole States in the D1–D5–P CFT
Ji-Seong Chae
We study BPS states in the D1–D5 CFT through their fortuity, cycle structure, and probe response. Explicit fortuitous states with both long- and short-string geometries show that the cycle partition does not determine fortuity state by state. At large $N$, fixed-charge counting nevertheless selects a long string. In the open uncondensed region, an
entropy-carrying exact non-graviton subspace concentrates on one cycle of winding $N-O(1)$. Assuming subexponential monotone dimension, the same holds for the harmonic fortuitous complement. Beyond the critical line, the free ensemble develops a short-string condensate. To test how this cycle structure appears in observables, we study finite-winding probes. The long-cycle scalar correlator approaches the extremal-BTZ response at fixed time, while finite winding is resolved at \(t=O(\sqrt N)\), the exact circle recurs at \(t=O(N)\), and states with the same cycle geometry remain distinguishable by their spectral weights.
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Statistical Mechanics
Speed-Fisher Information: Chaos and Irreversibility in Classical and Quantum Dynamics
Nachiket Karve, Nathan Rose, David Campbell et al. (+1 more)
We propose a unified perspective on classical and
quantum chaos based on the sensitivity of a system's stationary states to slow driving. We probe this sensitivity via the system's susceptibility to the average protocol speed, which we call the “speed-Fisher information," and relate it to irreversible
entropy production in the system. We show that chaotic dynamics manifests as a divergence of the speed-Fisher information with the protocol time, and that this response is controlled by the perturbation's low-frequency spectral weight. This approach to chaos applies to both classical and
quantum Hamiltonian systems, and naturally extends to non-
Hamiltonian classical flows. Additionally, we identify a
quantum regime at times shorter than the Planckian timescale, in which the speed-Fisher information exhibits a uniquely
quantum scaling. We illustrate this framework with simple classical and
quantum examples
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All authors Nachiket Karve, Nathan Rose, David Campbell, Anatoli Polkovnikov
Mathematical Physics · Cross-listed from math.PR
Power variations of critical Gaussian multiplicative chaos and their spectral applications
Mo Dick Wong
We introduce power variations of critical Gaussian multiplicative chaos (GMC) along refining partitions in arbitrary dimension. Under suitable renormalisation, we prove uniform fractional moment bounds via Laplace transform estimates as well as stable convergence to supercritical GMCs. Together, these results provide a unified approach to regularity and spectral questions for critical chaos, yielding: (i) the sharp exponent for the logarithmic modulus of continuity, (ii) the existence of non-empty essential spectrum for critical Liouville
quantum gravity surfaces; and (iii) an almost-sure quantitative
Fourier decay.
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Earth and Planetary Astrophysics
K-dwarf starspot hunters: how to directly characterize spot and faculae properties with UV-IR panchromatic transit spectra
Joanna K. Barstow, Caitlyn Cullen, Yvonne Unruh et al. (+7 more)
Transmission spectroscopy of
exoplanets provides an important window into their atmospheric composition, structure and dynamics, especially in the JWST era. As the quality of the observational data and therefore the precision of our constraints improves, we become increasingly sensitive to sources of systematic bias in our models and observations. One significant example of this is the Transit Light Source Effect, in which heterogeneous features in the
stellar photosphere - spots and faculae - imprint additional spectral signatures onto
exoplanet transmission spectra. The effects of this
stellar contamination must be accounted for or removed in order to accurately recover the
planet's atmospheric properties. Including parameterized models of spots and faculae within spectral
retrieval analysis is increasingly adopted as a solution to this problem, but is limited by the accuracy of models of
stellar spectra. In this paper, we outline an observational strategy combining simultaneous data from JWST and the Hubble Space
Telescope that would enable us to further constrain these models. We perform synthetic
retrievals to demonstrate how we could constrain starspot and faculae parameters; we test the impact of using different model spectra in the
retrieval; and we consider the impact of variable
stellar activity on coadding transits to achieve the desired signal-to-noise. We find that ultraviolet and optical wavelengths are key for breaking degeneracies between
stellar contamination and planetary parameters.
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All authors Joanna K. Barstow, Caitlyn Cullen, Yvonne Unruh, Hannah Wakeford, Eva-Maria Ahrer, Lili Alderson, Charlotte Fairman, Ulrich Kolb, Nikole Lewis, Cinta Vidante
Atmospheric and Oceanic Physics
Explainable Deep Learning for Probabilistic Nowcasting of Radar Reflectivity in Tornadic Storms
Nathan Erickson, Amy McGovern and Aaron Hill
Tornadoes pose substantial risk to human life and property in the United States, causing more than 50 fatalities and \$100 million of property damage on average annually. When tornadoes are likely, weather radar provides critical information for forecasters by providing information on storm morphology, storm motion, and intensity trends. Additional tools such as satellite and numerical weather prediction model runs can provide useful short-term information for understanding changes in storm characteristics. This work demonstrates a U-Net deep-learning system for nowcasting the
evolution of radar reflectivity following tornadogenesis, which can provide value to forecasters by synthesizing large amounts of input data (e.g., radar imagery, near-storm environment data) and generating predictions of radar reflectivity from its inputs. Inputs to the model are radar imagery from the Multi-Radar Multi-Sensor (MRMS)
dataset and near-storm environment data from the High-Resolution Rapid Refresh (HRRR) numerical weather prediction model. The U-Net is trained on a
dataset of tornadic storms to produce 30 minutes of probabilistic predictions of radar reflectivity following tornadogenesis, with probabilistic predictions obtained by predicting parameters of the SinhArcSinh, or SHASH, distribution. The model produces physically realistic predictions of radar
evolution, achieves comparable skill to next-hour forecasts from the HRRR, demonstrates reasonable probabilistic calibration and is accompanied by a variety of explainability methods to improve understanding by end users. Additionally, predictions from the model can be obtained much more quickly than those from a numerical weather prediction model. With further development, this model could be extended to nowcast radar reflectivity
evolution in an operational setting.
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Quantum Physics
Optimal Query Complexity for Ground-State Preparation
Boyang Chen, Minbo Gao, Xinzhao Wang et al. (+1 more)
We determine the optimal query complexity of ground-state preparation to trace-distance error $\varepsilon$ when an energy threshold in the spectral gap is known. Let $U_H$ be an $\alpha$-block-encoding of a
Hamiltonian with unique ground state $|\psi_0\rangle$, and suppose $|\langle\psi_0|U_I|0\rangle|\ge\gamma$ for a state-preparation oracle $U_I$. The threshold lies at least $\Delta/2$ above the ground-state energy and at least $\Delta/2$ below every excited-state energy. We give two
algorithms that prepare a state within trace distance $\varepsilon$ of the ground state. One uses $O((\alpha/\Delta)(\gamma^{-1}+\log(1/\varepsilon)))$ calls to $U_H$ in expectation; the other uses $O((\alpha/(\gamma\Delta))\log(1/\varepsilon))$ calls to $U_H$ in the worst case. We prove a lower bound matching the expected query count; the corresponding worst-case lower bound follows from Somma and de Wolf [SdW26]. The respective bounds on calls to $U_I$ are $O(1/\gamma)$ in expectation and $O(\gamma^{-1}\log(1/\varepsilon))$ in the worst case. On $(N+1)$-dimensional systems, these $U_I$ bounds are also optimal when the expected or worst-case count of $U_H$ calls, respectively, is $o((\alpha/\Delta)\sqrt N)$. Both
algorithms use a constant-accuracy spectral filter to construct a purifier, which we then sequentially compose during amplitude amplification to prepare a state with constant overlap with the ground state. The expected-query
algorithm repeats the preparation followed by one high-accuracy spectral filter until success. The worst-case
algorithm uses filters of increasing accuracy and limits the total number of queries.
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All authors Boyang Chen, Minbo Gao, Xinzhao Wang, Shuo Zhou
Materials Science
Pyroelectric thermo-wave probing of BaZr0.2Ti0.8O3 ceramics
Nicholas V. Morozovsky, Yuriy O. Zagorodniy, Mykola Yelisieiev et al. (+9 more)
BaxZr1-xTiO3 ceramics with 0.15 < x < 0.25, which have high dielectric permittivity, small leakage currents and low dissipation factor, are promising materials for tunable capacitor devices, multilayered ceramic capacitors and piezoelectric actuators. These materials reveal relaxor properties due to the local chemical strains caused by the isovalent substitution of Ti4+ ions by Zr4+ ions with a larger ionic size. However, to the best of our knowledge, the pyroelectric properties of BaxZr1-xTiO3 ceramics with x~0.2 have not been studied. To fill the gap in knowledge, we perform the pyroelectric thermo-wave probing of BaZr0.2Ti0.8O3 ceramics prepared by the solid-state synthesis. Results of the thermo-wave probing of the most interesting polar states, namely polarized, depolarized, relaxed and restored polarized states, reveal the pronounced pyroelectric response that can be strongly asymmetric with respect to the opposite surfaces of the ceramics. The asymmetry and profiles of pyroelectric response depend significantly on the pre-history of the electric field cycling indicating possible non-ergodic relaxor-type polar states in the ceramic sample. X-ray diffraction spectrum, recorded at room temperature, reveals the virtual absence of the macroscopic tetragonality and the weak asymmetry of the (200) peak, which indicate the small tetragonality inside the Ti-enriched polar nanoregions. Decrease of the relative intensity of the Raman band at 714 cm-1 occurring upon heating evidences the diffuse ferroelectric-paraelectric phase transition between 30 C and 40 C. The temperature dependence of the dielectric permittivity obeys modified Curie-Weiss law with power 1.4, indicating that both ordered ferroelectric and relaxor states coexist in the BaTi0.8Zr0.2O3 ceramics.Results can be useful for elaboration of lead-free relaxor ferroelectric ceramics for advanced pyroelectric applications.
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All authors Nicholas V. Morozovsky, Yuriy O. Zagorodniy, Mykola Yelisieiev, Oleksandr S. Pylypchuk, Mykola O. Semenenko, Iryna V. Kondakova, Lesya P. Yurchenko, Viktor Bovtun, Valentin V. Laguta, Eugene A. Eliseev, Volodymyr M. Dzhagan, Anna N. Morozovska
Instrumentation and Methods for Astrophysics
Accelerating massive ensembles of ordinary differential equations
Lawrence Berry, Will Handley, Oliver Hahn et al. (+1 more)
Solving large ensembles of small, independent ordinary differential equations (ODEs) is a common task in computational science and engineering, arising for example in
Bayesian parameter estimation, Monte Carlo uncertainty quantification, and the integration of uncoupled physical systems such as the linearised Einstein-Boltzmann equations of cosmology. Modern graphics processing units (GPUs) with thousands of cores are well suited to such parallel workloads, but realising this potential requires careful
attention to GPU-specific architectural constraints. We present modax, a Python library of GPU-accelerated ODE solvers specifically optimised for solving large ensembles of low-dimensional, independent problems. Our solvers are compatible with the JAX ecosystem but are written in a low-level, thread-based programming paradigm better suited to ensembles of highly divergent trajectories than their pure-JAX counterparts.
Benchmarks on the Lorenz, Robertson and van der Pol
lattice systems compare modax against diffrax, DiffEqGPU$.$jl and torchdiffeq across ensemble size, dimensionality, and trajectory divergence. Our explicit Tsit5 solver achieves 30x speed-up over diffrax on Lorenz systems, and our implicit Rodas5P solver achieves over 700x speed-up on Robertson systems, demonstrating the superiority of linearly implicit Rosenbrock-Wanner methods on GPUs. Our implicit solver scales well to higher dimensions thanks to the use of sparsity-exploiting techniques and data structures. We conclude by applying modax to three examples from the field of cosmology -
Bayesian parameter estimation from
primordial abundances, Monte Carlo uncertainty quantification of the global 21cm signal, and the computation of uncoupled
Fourier modes in the
primordial power spectrum - and demonstrate significant efficiency improvements in our ability to model physical phenomena described by low-dimensional (<200D) ODEs.
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All authors Lawrence Berry, Will Handley, Oliver Hahn, Nils Schöneberg
Quantum Physics
Carlos Bravo-Prieto, Aram W. Harrow and Robin Kothari
In the
quantum linear systems problem (QLSP), we are given query access to a $d$-sparse $N\times N$
matrix $A$ with condition number $\kappa$, and the ability to prepare a
quantum state proportional to a vector $\vec b$. The goal is to output an $\epsilon$-approximation to the
quantum state proportional to the solution $\vec x$ of $A\vec{x}=\vec{b}$. Following a long line of work, the best previously known
quantum algorithms for the QLSP had query complexities $O(\kappa d\log(1/\epsilon))$ and $\kappa\sqrt d(\kappa d/\epsilon)^{o(1)}$, while the best known lower bounds were $\Omega(\kappa\log(1/\epsilon))$ and $\Omega(\kappa\sqrt d)$. We improve these bounds and show that the complexity of the QLSP is $\Theta(\kappa\sqrt d\log(1/\epsilon))$. We also resolve an open problem of Berry and Childs by showing that any $N\times N$
unitary can be implemented with bounded error using $O(\sqrt N)$ queries to its
matrix entries.
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Quantum Physics
The power of oracle access: Optimal sample and query complexity of the abelian state hidden subgroup problem
Yuhan Liu, Jose Carrasco, Jens Eisert et al. (+1 more)
In the quest to identify further
quantum algorithms exhibiting superpolynomial speed-ups, a recurring theme is that the complexity of a problem is largely shaped by the input access model. Here, we study this phenomenon for the state hidden subgroup problem (StateHSP), a
quantum generalization of the hidden subgroup problem in which the goal is to identify the
symmetries of an unknown
quantum state. For finite abelian groups, existing
Fourier-sampling
algorithms use $O(\log(|G|)/\epsilon)$ copies of the state, but whether this scaling is optimal has remained open. We settle the complexity of the abelian StateHSP in both the previously studied sample model and a new query model, which is a stronger and operationally natural generalization that provides access to the state-preparation
unitary and its inverse. In the query model, we give a time-efficient
quantum algorithm using $O(\log(|G/H|)/\sqrt{\epsilon})$ forward and inverse queries, and prove a matching $\Omega(\log(|G/H|)/\sqrt{\epsilon})$ lower bound which holds even in the stronger conjugate-query and controlled-query settings. By contrast, we show that in the sample model, $\Theta(\log(|G/H|)/\epsilon)$ copies are both sufficient and information-theoretically necessary, even if one allows for arbitrary collective measurements. Thus, the quadratic improvement in $\epsilon$ genuinely arises from coherent access to the preparation
circuit. As applications, we obtain faster
algorithms for learning stabilizer groups, locating unentanglement, and identifying hidden translation
symmetries.
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All authors Yuhan Liu, Jose Carrasco, Jens Eisert, Armando Bellante
Quantum Physics
Optimal performance in a chaotic Floquet quantum battery
Lakshmija N K and Uma Divakaran
We study a
quantum battery consisting of $N$
qubits interacting uniformly with each other. Starting from its ground state, the battery is charged by introducing periodic kicks in the transverse direction along with adding disorder in the interaction direction. Although the battery
Hamiltonian along with the initial state preserves the permutation
symmetry, the dynamics in presence of disorder during the charging phase takes the system out of the permutation symmetric subspace, resulting to a larger amount of stored energy as compared to that without disorder. In the limit of large disorder, this interplay brings in a possibility of a chaotic charging phase when stored energy can be exactly calculated using random
matrix theory. More importantly, we also find that the energy fluctuations decrease and become negligible in the limit of large disorder, which is also when the energy stored is maximum, a condition highly desirable for the optimum functioning of the battery. We complete the battery cycle by considering the storage phase in the presence of dephasing noise. We find that for larger disorder strengths, the ergotropy remains close to the stored energy, indicating nearly complete energy extractability with an efficiency approaching unity.
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High Energy Physics (Phenomenology)
Factorization and virtuality evolution of jet functions in heavy-ion collisions
Carlos Lamas, Carlos A. Salgado and Bin Wu
We develop a new framework to perform a virtuality-resolved description of jet propagation in heavy-ion collisions using perturbative techniques. The role of virtuality is rigorously identified by first deriving a factorized jet cross section that defines an in-medium jet function. This new definition allows to extend the usual BDMPS-Z formalism to include the virtuality-differential transverse momentum broadening distribution and medium-induced soft
gluon spectrum. We study both the cases of a medium which is created with some delay time $\tau_0$ after the hard collision as well as the case in which $\tau_0\to 0$. Integration over the complete virtuality range recovers the standard BDMPS-Z results, while finite virtuality reveals the interplay between
vacuum-like
evolution and medium-induced dynamics. We identify the ratio between the medium formation time and the jet formation time as the variable controlling which initial virtualities contribute appreciably to the jet function.
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High Energy Physics (Phenomenology)
The LZ event with a two-state dark matter halo
Vinicius Oliveira
The LUX-ZEPLIN (LZ) experiment has reported a single
nuclear-
recoil candidate at $E_R \simeq 248$keV. LZ interprets it in terms of inelastic dark matter that scatters endothermically from its ground state, $\chi_1 N \to \chi_2 N$. In pseudo-Dirac models the excited state $\chi_2$ can survive to the present day, and exothermic scattering, $\chi_2 N \to \chi_1 N$, is then also open. The published LZ intervals do not describe this case. We rebuild the LZ statistical inference and validate it against the published intervals. We then apply it to a
halo that contains a fraction $f$ of $\chi_2$. For $f \gtrsim 10^{-5}$–$10^{-2}$, depending on the mass splitting, the exothermic contribution dominates. For $f=1/2$ the cross section required by the candidate drops by factors of $80$ to $1.6\times10^4$ for $\delta = 250$–$350$~keV, and the kinematic cutoff of the endothermic signal disappears. A
benchmark that explains the event with $\chi_1$ alone lies a factor of $30$ above the upper limit when half of the
halo is $\chi_2$.
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