Cosmology and Nongalactic Astrophysics
Non-Primordial Contribution to the Cosmic Microwave Background
Akshith Asundi and Vikram Khaire
The
cosmic microwave background is interpreted as relic thermal radiation from the epoch of recombination at z~1090. Recent work by Gjergo & Kroupa (GK25) have challenged this assumption proposing that
dust-enshrouded starbursts in the progenitors of massive early-type
galaxies at z~15-20 contribute to the CMB at the percent level of the present-day CMB energy density. Existing test of this scenario rely on CMB monopole; here we present the first test against the CMB anisotropy power spectrum, which probes the dynamical imprint of the radiation content on the sound horizon and acoustic peaks. We introduce a single parameter $\varepsilon_{\rm CMB}$ that rescales the
primordial photon energy density above a
redshift (z=17). Constraining the model with the Planck 2018,
lensing likelihoods and BAO measurements, we find a percent-level
dust contribution to be fully consistent with the data. When we restrict $\varepsilon_{\rm CMB}\leq1$, the data place a 68 (95) per cent lower bound $\varepsilon_{\rm CMB}\gtrsim 0.971$(0.953), permitting a non-
primordial contribution of up to ~3 (~5) per cent of the CMB energy density. When sampled with $\varepsilon_{\rm CMB}$ as a free parameter, the data yield a well-resolved posterior with $\varepsilon_{\rm CMB} = 1.0104^{+0.025}_{-0.024}$. The 1.4 per cent contribution conservatively estimated by GK25 lies within the 1$\sigma$ region of both cases, whereas a contribution approaching the full CMB energy density is excluded at 42$\sigma$. Treating z as a free parameter returns a flat posterior across 5<z<50 indicating the anisotropy constrains the
dust contribution, but not when it occurs. The standard LCDM parameters are recovered without significant shifts, showing that current CMB precision cosmology has sufficient room to accommodate a
dust contribution at the level predicted by GK25 without detectable consequence for parameter inference.
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High Energy Physics (Phenomenology)
Dark matter in composite Higgs models with a scotogenic EFT
Yu Chen and Werner Porod
We discuss a class of Composite
Higgs models with a fermionic UV completion that can explain the dark matter relic density. The resulting low-energy theory resembles so-called scotogenic models. A residual $\mathbb{Z}_2$
symmetry implies that one of the pseudo-Nambu-Goldstone
bosons is stable and therefore is a viable dark matter candidate. As a concrete example, we take a model based on the $\mathrm{SU}(6)/\mathrm{Sp}(6)$ coset, which in principle contains four dark matter candidates. However, only three of them can produce a relic density consistent with observations. We perform a MCMC study focusing on dark matter observables to explore the available parameter space of the effective theory. In particular, we find that
spin-1 resonances play an important role in a substantial part of the parameter space. Finally, we comment on possible LHC signatures of this model class.
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Cosmology and Nongalactic Astrophysics
The topology of the magnetic field in Abell 2255 out to its virial radius. Results from the LOFAR Galaxy Cluster Ultra-Deep Field
A. Botteon, R. J. van Weeren, Y. Hu et al. (+14 more)
We present the LOFAR
Galaxy Cluster Ultra-Deep Field, in which 336 h of LOFAR observations at 120$-$168 MHz have been collected on the nearby ($z=0.080$) cluster Abell 2255. This massive and merging system is known to host spectacular
radio emission from both cluster
galaxies and the intracluster medium. Previous LOFAR observations revealed pervasive diffuse synchrotron emission extending from the cluster center to its dynamically active outskirts, tracing relativistic electrons propagating in large-scale
magnetic fields. In this work, we present a set of new ultra-deep images at the central frequency of 144 MHz based on the 224 h of data with the best quality, which reach a sensitivity of 24 $\mu$Jy beam$^{-1}$ at 7.1" $\times$ 4.3" resolution. These images represent the deepest
radio observations of a
galaxy cluster obtained to date and provide a glimpse of what should be routinely observed in clusters with SKA-Low in the near future. Using these data, we investigate the
topology of the cluster
magnetic field out to its virial radius by applying the synchrotron intensity gradient technique. We find that the inferred
magnetic field exhibits preferential orientations in distinct regions of the cluster, such as in the
radio halo extensions (bridges) and in the relics, suggesting that the dynamics of the cluster formation process is shaping the large-scale
magnetic field. This interpretation is supported by the comparison with the
magnetic field orientation obtained from cosmological magnetohydrodynamic simulations. This work provides the first indication of a coherent, large-scale
magnetic field
topology across an entire
galaxy cluster, from core to outskirts, and demonstrates the unique power of ultra-deep, low-frequency observations to trace the structure of cluster
magnetic fields on megaparsec scales, thereby probing the magnetization of the large-scale structure of the Universe.
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All authors A. Botteon, R. J. van Weeren, Y. Hu, F. Vazza, G. Brunetti, K. Rajpurohit, A. Lazarian, T. W. Shimwell, E. De Rubeis, M. Balboni, A. Bonafede, R. Cassano, G. Di Gennaro, F. Gastaldello, M. J. Hardcastle, A. Ignesti, H. J. A. Röttgering
Solar and Stellar Astrophysics
The Open Cluster Chemical Abundances and Mapping Survey: IX. Measuring the Effects of Stellar Diffusion in the Open Clusters NGC 752 and Ruprecht 147 using APOGEE
Diogo Souto, Taylor Spoo, Peter M. Frinchaboy et al. (+4 more)
A growing understanding of
stellar processes that alter surface chemical abundances over time has opened new avenues for using these changes as probes of
stellar properties. On the main sequence and near the turnoff,
stellar surface abundances are affected by gravitational settling and radiative acceleration, collectively known as atomic
diffusion. In this work, we use SDSS/APOGEE DR17/DR19 data to investigate atomic
diffusion in the open clusters NGC~752 and Ruprecht~147, thereby constraining how these signatures vary with age. From the analysis of Fe, C, N, Na, Mg, Al, Si, S, K, Ca, Ti, V, Cr, Mn, Co, and Ni, we find significant abundance differences between
stars near the turnoff and the cooler main-sequence, where warmer
stars are depleted relative to the cooler main-sequence
stars at the $\geq1\sigma$ level for all elements available in the analysis. These abundance differences are consistent with the signatures expected from atomic
diffusion and are further supported by comparisons with
stellar models that include
diffusion. By fitting the observed $T_{\rm eff}$–[Fe/H] patterns with MIST isochrones, we obtain best-fit ages of 1.0~Gyr for NGC~752 and 2.5–3.2~Gyr for Ruprecht~147. Carbon is a key diagnostic, as it shows both atomic
diffusion and extra-mixing signatures associated with first-dredge-up. For NGC~752, the coolest
stars in our sample, which provide the best proxy for the initial cluster composition, yield [Fe/H]$_{\rm CS} = 0.01~\pm~0.02(\pm~0.05)$ dex. For Ruprecht~147, we obtain [Fe/H]$_{\rm CS} = 0.17~\pm~0.00(\pm~0.05)$ dex. Our findings further constrain atomic
diffusion models, suggesting that atomic
diffusion affects age estimates of
stars near the main-sequence turnoff.
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All authors Diogo Souto, Taylor Spoo, Peter M. Frinchaboy, Katia Cunha, Jamie Tayar, Alessa Ibrahim Wiggins, Natalie Myers
Cosmology and Nongalactic Astrophysics
Measuring satellite galaxy subhalo masses in redMaPPer clusters with UNIONS weak lensing data
Roman Akhmetshyn, Jack Elvin-Poole, Michael J. Hudson et al. (+13 more)
In this work, we present the observed
galaxy-
galaxy lensing signal of satellite
galaxies in rich clusters obtained from the Ultraviolet Near-Infrared Optical Northern Survey (UNIONS). Such observations are crucial for understanding dark matter
halo physics and interaction dynamics in the cluster environment. Our goal is to investigate the
tidal stripping of cluster subhalos. Theoretical predictions, supported by recent studies, suggest that as satellite
galaxies fall into clusters, their dark matter
halos are stripped and dispersed into the cluster's main
halo, while their
stellar mass remains relatively intact. A robust method to probe this phenomenon is through statistical measurements of the excess surface mass density of satellite
galaxies at different cluster-centric distances. Our results reveal a significant
lensing signal, with strong statistical power from the large number of lens-source pairs. A simple model used in the fitting process to constrain subhalo masses effectively reproduces the observed
lensing signal at relevant satellite-centric distances. However, it lacks the complexity to accurately fit the excess surface density at larger distances, where the host cluster
halo dominates. We measure the subhalo-to-
stellar mass ratio as a function of cluster-centric radius and find a strong positive trend. These results confirm
tidal stripping or other environmental processes that impact the relative masses of a satellite
galaxy's
stellar component and its dark matter
halo.
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All authors Roman Akhmetshyn, Jack Elvin-Poole, Michael J. Hudson, Isaac Cheng, Thomas de Boer, Sébastien Fabbro, Sam Farrens, Sacha Guerrini, Axel Guinot, Stephen Gwyn, Hendrik Hildebrandt, Martin Kilbinger, Charlie T. Mpetha, Calum Murray, Ludovic Van Waerbeke, Anna Wittje
Cosmology and Nongalactic Astrophysics
Simulation-Based Priors for HI Bias from Halo Occupation Physics
Debanjan Sarkar and Simon Foreman
Full-shape analyses of 21 cm intensity maps with the effective field theory of large-scale structure will require priors on HI bias parameters, and the standard choice of broad uninformative priors can lead to cosmological constraints that are unnecessarily conservative. We present a simulation-based framework that replaces these broad priors with informative priors based on learning the conditional distribution $p(\bm{\theta}_{\rm EFT}\mid\bm{\theta}_{\rm HOD})$ between effective-field-theory-based bias parameters and the parameters of a model for HI clustering in the nonlinear regime. Specifically, we train a conditional normalizing flow on field-level measurements of the lowest-order local bias parameters $(b_1,b_2,b_3)$ and the
tidal bias $b_{\mathcal{G}_2}$ by applying a simple HI
halo occupation distribution (HOD) to the Hidden Valley simulations. We find that the resulting HOD-to-bias mapping is highly structured, displaying a strong dependence on the power of
halo mass in the HOD model. Propagating CHORD-like
telescope sensitivity forecasts for the 21 cm power spectrum on nonlinear scales through this mapping produces non-Gaussian, correlated priors on the bias parameters that are substantially tighter than conventional flat priors across $z=1$–$3$, with the improvement most dramatic at high
redshift. By repeating our analysis using
halo catalogs from the IllustrisTNG simulations, we find non-negligible differences from the Hidden Valley results, indicating that future applications of simulation-based HI priors will need to carefully account for the dependence of these priors on the simulations used to construct them. Our framework provides an initial step toward informative EFT priors for current and forthcoming HI intensity mapping surveys, including CHIME, CHORD, and MeerKLASS.
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Mathematical Physics · Cross-listed from math.DG
A Self-Dual Frame Formalism of the SO(3) Yang-Mills Theory
Hanwen Liu
For a closed oriented Riemannian $4$-
manifold $(M,g)$, we consider $\operatorname{SO}(3)$ connections on the bundle $\Lambda^+$ of self-dual $2$-forms. On the open locus where the self-dual
curvature is an orientation-preserving frame, pointwise polar decomposition removes the gauge freedom and replaces the connection by a positive self-adjoint endomorphism field $h$ of $\Lambda^+$. Using the classical reconstruction of the compatible connection $A(h)$, we obtain a global formulation of the Yang–Mills equation as the determined second order system $$ \Phi_g(h):=F_{A(h)}^+h^{-1}-\operatorname{Id}=0. $$ Here, the tensor $F_{A(h)}^+$ is the self-dual
curvature of $A(h)$, regarded as an endomorphism of $\Lambda^+$, and $\operatorname{Id}$ is the identity of $\Lambda^+$. We establish a variational formulation, automatic irreducibility,
elliptic regularity, and a Fredholm index
theorem for the linearized operator $D_h\Phi_g$. For fields of the form $h=e^{2\omega}\operatorname{Id}$, where $\omega$ is a smooth real-valued function on $M$, the equation $\Phi_g(h)=0$ is equivalent to anti-self-duality and constant scalar
curvature $6\sqrt{2}$ of the conformal metric $\hat g=e^{2\omega}g$. Consequently, every anti-self-dual conformal class of positive Yamabe constant gives a global solution of $\Phi_g(h)=0$.
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History and Philosophy of Physics
The orientation of the Amazonian geoglyphs as a clue for their interpretation
Giulio Magli
Amazonian earthworks, also called geoglyphs, are thousands of man-made earthen structures, mostly of geometrical shape, which progressively emerged from the tropical forest due to progressive deforestation. They were probably built between the fifth century BC and the end of the first millennium AD, but archaeological investigation on the culture of their builders is yet at the beginning. Nevertheless, a ceremonial rather than practical function seems likely, at least for those having a very regular shape. In the present paper, simple remote-sensing technique, combined with the methodological approach of modern Archaeoastronomy, are applied to study for the first time their orientation. The analysis takes in consideration virtually all known squared and rectangular structures for a total of 326 earthworks. The results show without doubts a non-random choice for their orientation and a clear interest of their builders for the annual cycle of the Sun.
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Instrumentation and Methods for Astrophysics
Development and characterization of a millimeter-wave cold load prototype
Ruya Cong, Junjie Zhou, Yu Xu et al. (+7 more)
Superconducting transition-edge sensors (TESs) are crucial detectors for
cosmic microwave background (CMB) observations and require stable and tunable millimeter-wave cold loads for optical-efficiency calibration. This work presents the design, fabrication, and preliminary characterization of a 4-20 K millimeter-wave cold load prototype intended for integration into the 1 K stage of a dilution refrigerator and subsequent 40/90 GHz CMB TES calibration experiments. Two absorber prototypes based on commercially available CR-110 and a Stycast 2850FT composite were fabricated and studied. Simulation results show that both absorber structures exhibit small predicted steady-state temperature gradients and low normal-incidence reflectance in the target frequency bands. Room-temperature S11 measurements were used only to screen low-reflectance cold load prototype, and the measured results generally agree with the electromagnetic simulations. The measured S11 of the Stycast 2850FT composite is comparable to that of the commercial absorber TK RAM. Additionally, to explore a more readily obtainable alternative absorber material, TIE280-25AB was preliminarily evaluated by measuring its electromagnetic parameters. Based on the measured parameters, the simulated S11 of the TIE280-25AB pyramidal absorber structure is comparable to those of CR-110 and the Stycast 2850FT composite over 33-110 GHz. These results identify CR-110 and the Stycast 2850FT composite as promising absorbers for subsequent cryogenic evaluation. The absolute low-temperature emissivity, effective radiation temperature, and TES calibration performance remain to be established through future cryogenic radiometric and TES based optical-power measurements.
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All authors Ruya Cong, Junjie Zhou, Yu Xu, Xuefeng Lu, Jianrong Cai, Haoxuan Gao, Kang Zhang, Xingyuan Hou, Zhengwei Li, Shaoliang Wang
Atmospheric and Oceanic Physics
OCELOT: Direct Atmospheric Forecasting from Heterogeneous Earth Observations Using a Graph-Transformer Hybrid Model
Azadeh Gholoubi, Ronald McLaren, Mu-Chieh Ko et al. (+7 more)
This study presents OCELOT (Observation-Centric Estimation and Learning for Outlook Trajectories), a global machine-learning
forecasting system that predicts future Earth observations directly from heterogeneous satellite and in-situ measurements. Unlike data-driven weather models trained on gridded reanalysis states, OCELOT operates natively in observation space, preserving instrument-specific sampling, viewing geometry, and measurement characteristics. The system combines per-instrument graph-
attention encoders, a shared spherical icosahedral latent mesh, a hybrid sliding-window
Transformer/spatial graph neural network processor, and metadata-conditioned decoders to produce forecasts up to 12 h ahead. OCELOT is trained on observations for the years 2015 through 2023, validated on the year 2024, and evaluated out of sample on 2025 observations across satellite radiances, radiosondes, aircraft, and surface networks. In the 2025 evaluation, OCELOT produces spatially coherent +12 h forecasts across independent observing systems: microwave temperature-sounding channels show RMSE values of 1.24-1.87 K, while the more surface- and cloud-sensitive AVHRR infrared window channel shows a higher RMSE of 3.95 K. Vertical profile diagnostics show physically consistent radiosonde and aircraft temperature structure. Surface forecasts remain stable through 12 h, with 2-m air-temperature RMSE increasing from about 3.2 K at +3 h to about 3.6 K at +12 h. In paired observation-space comparisons, OCELOT remains less accurate than operational GFS but substantially outperforms persistence at longer lead times for 2-m temperature and 10-m wind components. These results demonstrate that observation-space
forecasting can recover large-scale atmospheric structure and provide meaningful short-range skill without reanalysis supervision.
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All authors Azadeh Gholoubi, Ronald McLaren, Mu-Chieh Ko, Xin Jin, Nicholas Esposito, Andrew Collard, Cory Martin, Russ Treadon, Daniel Holdaway, Daryl Kleist
Medical Physics · Cross-listed from stat.ML
Operator-Informed Gaussian Processes for Complex Helmholtz Wavefields: From Synthetic Benchmarks to In Vivo Brain Elastography
Boyuan Deng, Kshitiz Upadhyay and Michael Shields
The Helmholtz equation governs time-harmonic wave propagation, and in dissipative media a complex modulus renders its squared wavenumber $\kappa^2$ complex. Inferring such fields from sparse, noisy data calls for solvers that also quantify their own uncertainty. Physics-informed Gaussian-process (GP) regression supplies this by returning a posterior over the solution, yet operator-conditioned formulations have been developed almost exclusively for real-valued fields. We extend operator-informed GP regression to complex-valued Helmholtz problems by realifying the complex operator into an equivalent coupled real block, which enables inference with standard real-valued GP conditioning. The construction admits a family of priors, from a proper diagonal prior to coregionalized and multiscale variants, and conditions on PDE residuals and boundary traces. On
benchmark problems in one to three dimensions, the solver is competitive with finite-difference and neural-network baselines at a far smaller interior-constraint budget. Unlike those deterministic baselines, it returns a posterior over the complex wavefield rather than a point estimate. Applied to in vivo
brain magnetic resonance elastography, a proper multiscale prior reconstructs the shear curl field to a correlation of $0.77$ with measurement, above a $0.75$ target. The gain arises from the multiscale kernel rather than from real–imaginary coupling. We further identify a low-frequency accuracy ceiling set by model mismatch and a posterior uncertainty that is not yet calibrated. Calibrated uncertainty therefore emerges as the central next step for probabilistic wavefield inference in dissipative media.
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General Relativity and Quantum Cosmology · Cross-listed from math.AG
Sheaves for spacetimes: a survey
Pierre Schapira
On a spacetime endowed with a time function (such as a globally
hyperbolic manifold) we solve the global Cauchy problem for
hyperbolic D-modules in the framework of Sato's hyperfunctions, illustrating the effectiveness of microlocal-sheaf theoretic methods in linear problems.
Quantum Physics
Transducer leakage error suppression using invariant-based shortcut
Shi-Qiang Qiao, Zheng Shan, Xue-Ke Song et al. (+3 more)
We present a method for suppressing transducer leakage errors in
spin-superconducting hybrid
quantum systems with the theory of optimal invariant-based shortcut. By mediated virtual
photons as a transducer to exchange the energy between the
spin qubit and a transmon
qubit, the fidelity of the population of the final state features a broad range above 99% under the influence of leakage error. The leakage probability from computational subspace to non-computational subspace can be effectively suppressed at a lowest value with $0.01$. Based on the optimized pulse control designed by the invariant-based inverse engineering, the high-fidelity
quantum iSWAP gate operations and
entanglement state preparation within the computational subspace are achieved. {Compared to the traditional $\pi$ pulse, derivative removal by adiabatic gate, counter-diabatic shortcut schemes, and limited-
memory Broyden-Fletcher-Goldfarb-Shanno gradient ascent pulse engineering, the optimized shortcut scheme can still achieve a high fidelity with 99% in the presence of decoherence and control error.} When taking into account the possibility of leakage errors in actual situations, our solution can still largely resist the influence of control errors. The results provides a feasible path for precisely manipulating the
quantum state of hybrid
quantum systems.
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All authors Shi-Qiang Qiao, Zheng Shan, Xue-Ke Song, Shi-Lei Su, Liu Ye, Dong Wang
General Relativity and Quantum Cosmology
Novel topological subclass in Bardeen-AdS-class black holes
Yu-Die Wan, Peng Zhao and Zheng-Wen Long
Based on the $\phi$-mapping topological current theory, we systematically investigate the thermodynamic
topology of regular Bardeen-AdS-class black holes coupled to nonlinear electrodynamics, a class of singularity-free geometries whose topological classification remains underexplored. We implement numerical calculations at two typical AdS radii $L=1$ and $L=15$. Within the fundamental $W^{0-}$ topological family, we identify a novel inner secondary subclass $\widetilde{W}^{0-}$. This result only refines and enriches the internal branch structure of the $W^{0-}$ family under the established classification scheme of five topological classes and four topological subclasses for black hole thermodynamics. This new subclass has a vanishing global topological charge $W=0$ with an inner-outer horizon winding-number signature $[-,+]$. Unlike standard $W^{0-}$ solutions that realize topological extension via embedded $(+,-)$ winding pairs, $\widetilde{W}^{0-}$ arises from attaching an extra stable branch to the end of the base solution sequence. Two critical coupling parameters $\hat{m}_{01}$ and $\hat{m}_{02}$ divide the full parameter space into distinct topological phases: Type I black holes with $m_0\ge\hat{m}_{01}$ and Type II solutions with $\hat{m}_{02}<m_0<\hat{m}_{01}$ belong to $\widetilde{W}^{0-}$, while the parameter region $0<m_0\le\hat{m}_{02}$ corresponds to the conventional $W^{0-}$
topology. Our numerical results verify the self-consistency of the thermodynamic topological formalism when applied to singularity-free regular black holes, refine the topological discrimination criteria tailored to nonlinear-electrodynamics regular black holes, and provide theoretical references for subsequent topological investigations of higher-dimensional rotating regular black holes under the same formalism.
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General Relativity and Quantum Cosmology
Probing Quantum Gravity through Chaotic Orbits and Strong-Field Effects in Kerr Black Holes Embedded in Perfect Fluid Dark Matter
Shubham Kala, Sara Saghafi, M. Yousaf et al. (+4 more)
We study the nonlinear
photon dynamics in
quantum improved rotating black hole surrounded by perfect fluid dark matter (PFDM) using several methods of analysis, including Poincaré sections, Lyapunov exponents, Kolmogorov-Sinai (KS)
entropy and weighted Birkhoff averages (WBA). In particular, we examine the effect of
quantum-improved parameter $(\tilde{\omega})$ and PFDM parameter $(\zeta)$ on the null geodesic motion hence stability of circular orbit. Poincaré sections illustrate the transition from regular to chaotic motion as these parameters increase, characterized by the deformation and fragmentation of invariant
tori and the emergence of scattered chaotic regions in phase space. The stability properties of null circular orbits are quantified through the Lyapunov indicators, revealing that both the
quantum improvement parameter and the PFDM parameter enhance the sensitivity of
photon trajectories to initial conditions. The KS
entropy provides an independent measure of dynamical complexity and confirms the growth of chaotic behavior with increasing
quantum and PFDM corrections. Additionally, the WBA method offers a robust quantitative criterion for distinguishing regular and chaotic orbits and allows a detailed mapping of the phase-space structure. The results demonstrate that the combined effects of
quantum gravity corrections and PFDM significantly modify the effective potential governing
photon motion, leading to a rich mixed phase-space structure with coexisting regular and chaotic regions. These findings underscore the crucial role of
quantum and dark matter contributions in shaping
photon dynamics near rotating black holes and suggest possible observational implications on black hole shadows and gravitational
lensing in strong-field regimes.
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All authors Shubham Kala, Sara Saghafi, M. Yousaf, Hemwati Nandan, Ahmadjon Abdujabbarov, Chengxun Yuan, G. Mustafa
General Relativity and Quantum Cosmology
Breaking the Degeneracy: Spectral Hardening of Accretion Disks around Rotating Hayward Black Holes in Dark Matter Halos
Sandip Dutta
We investigate the thermodynamic and observable signatures of thin
accretion disks surrounding rotating, regular Hayward black holes embedded within a macroscopic dark matter (DM) envelope. The spacetime is rigorously modelled as a three-region composite: an inner Hayward core regularised by a de~Sitter limit, an intermediate DM shell modelled as a pressureless
dust envelope governed by an exponential sphere density profile, and an asymptotically flat outer
vacuum. By matching these regions via the mass profile, we compute the explicit modifications to the Innermost Stable Circular Orbit (ISCO), radiative efficiency, local thermal flux, and multi-colour blackbody spectral luminosity. A systematic comparison across four distinct configurations (Kerr
vacuum, Hayward
vacuum, Kerr\,+\,DM, and Hayward\,+\,DM) reveals a strict hierarchical compression of the ISCO. We demonstrate that the
quantum-inspired core regularity and the macroscopic DM
halo exert an additive enhancement on the radiative efficiency, reaching $\sim 14.4\%$ for highly spinning black holes ($j=0.8$). However, this additive behaviour introduces a profound macroscopic degeneracy between purely
geometric (Hayward
vacuum) and purely astrophysical (Kerr\,+\,DM) configurations at low-to-intermediate frequencies. We establish that this degeneracy is structurally broken only in the extreme Wien tail of the multi-wavelength spectrum, providing a critical diagnostic footprint for future high-frequency spectropolarimetry to distinguish non-singular black holes from classical dark matter environments.
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Quantum Physics
Pair-Partition Constructions for CPM-Based Quantum LDPC Codes
Koki Okada and Kenta Kasai
We introduce the pair-partition (PP) construction of binary Calderbank–Shor–Steane
quantum low-density parity-check codes from circulant permutation
matrices. A square array of pair partitions imposes linear paired-difference equations on the CPM exponents and thereby guarantees CSS orthogonality. Pairing graphs derived from this array allow the combinatorial design to be screened before exponent search. We further give and prove a complete
algorithm for verifying lower bounds on the
quantum minimum distance of a fixed CSS lift. The
algorithm searches for zero-syndrome vectors outside the opposing stabilizer row space, uses only rigorously valid
pruning rules, and finds no vector through a prescribed weight if and only if the corresponding distance exceeds that weight. For fixed column weight, row weight, and search limit, cyclic
symmetry makes the combinatorial support-enumeration bound independent of the lift size, although
matrix preprocessing and row-space tests can still depend on the lift size. Thus the construction stage and the distance-verification stage are both specified by directly checkable finite procedures.
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Astrophysics of Galaxies
Cold Stream Penetration of Virial Shocks: Fragmentation, Coagulation, and Disruption in the Hot Circumgalactic Medium
Zhiyuan Yao, Nir Mandelker and S. Peng Oh
Cold streams penetrating virial shocks of massive
halos along
cosmic web filaments are expected to fuel
galaxy growth at high
redshift, yet the physical processes governing their penetration remain uncertain. We investigate cylindrical cold streams penetrating a hot circumgalactic medium (CGM) using idealized three-dimensional simulations. We systematically vary the stream radius, Mach number, and initial stream-to-CGM pressure contrast across three density contrasts, while controlling stream properties after pressure
equilibrium is re-established. We identify three evolutionary regimes: coagulation, fragmentation, and disruption, plus a borderline regime in which the stream core marginally survives while detached fragments are disrupted. At modest pressure contrast, survival depends primarily on the competition between velocity shear and radiative cooling. Increasing pressure contrast produces a transient response during pressure restoration, temporarily enhancing or suppressing cold-gas mass and cold-hot interfacial area before
evolution converges to a shear-dominated state. At larger pressure contrasts, the oblique shock steepens into a bow shock, and the final outcome is determined by the ratio of post-shock cooling time to virial crossing time. In all survival cases, post-equilibration
evolution is well described by turbulent radiative entrainment at the stream-CGM interface: cold-gas mass flux increases while mean streamwise momentum flux remains approximately conserved. Applying these results to a
galaxy evolution framework, we find that cold streams are expected to penetrate virial shocks around massive
halos at $z>2$, though they may fragment into multiphase structures within the hot CGM at $M_\mathrm{v}\gtrsim2\times10^{12}\,\mathrm{M}_\odot$. Toward lower
redshift, bow-shock heating and inefficient post-shock cooling can suppress cold-stream penetration.
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Quantum Physics
Sail membranes for optomechanical accelerometry
Atkin D. Hyatt, Mitul Dey Chowdhury, Mahir Chowdhury et al. (+2 more)
Strained membrane resonators have emerged as a promising platform for optomechanical accelerometry; however, the desired combination of low frequency and high $Q$-mass product requires a rethinking of their dissipation dilution engineering. Applying
Bayesian optimization to a Si$_3$N$_4$ membrane, we discover a class of sail-like trampoline resonators in which the frequency is decreased by an order of magnitude while preserving the $Q$-mass product. We demonstrate centimeter-scale sails with kHz frequencies, $Q\sim10^7$ and $Q\times\text{mass}\sim$ 10 g. Vertically integrating a 7 kHz device with a nanoribbon, we realize a monolithic cavity optomechanical accelerometer with a room temperature thermal noise of $40\;\text{n}g_0/\sqrt{\text{Hz}}$, sufficient to resolve $\mu g_0/\sqrt{\text{Hz}}$ ambient vibration over a bandwidth of 4 kHz with a displacement imprecision of $10^{-14}\;\text{m}/\sqrt{\text{Hz}}$. Cryogenic arrays of sail membranes may be attractive for new physics searches and distributed
quantum sensing experiments.
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All authors Atkin D. Hyatt, Mitul Dey Chowdhury, Mahir Chowdhury, Mohamed J. Ahamed, Dalziel J. Wilson
Quantum Physics
Trigonometric Continuous-Variable Quantum Gates: Realization with Trapped Ions and Nonperturbative Wigner Negativity
Tommaso Rainaldi, Jake Montgomery, Christopher G. Yale et al. (+8 more)
We experimentally realize trigonometric continuous-variable gates on a trapped-ion processor, for which a motional mode acquires a phase proportional to the cosine of its position quadrature, and, for the first time, implement the two-mode generalization, coupling two modes through a single nonlinear phase. Such gates provide an experimentally accessible, nonpolynomial primitive for periodic interactions acting on both compact and noncompact degrees of freedom, including rotor models, sine-Gordon-type systems, and
lattice gauge theories. Scanning gate strength, spatial frequency, and
circuit depth, we resolve via blue-sideband spectroscopy the parity selection rule that fingerprints the exact cosine
evolution, and find that an open-system model incorporating residual thermal occupation and motional dephasing reproduces the data. We then derive the asymptotics of the Wigner negativity generated by these gates and find three scaling regimes. The negativity is beyond all algebraic orders in the gate strength while the negative regions sit in far phase-space tails, becomes linear once they reach the bulk, where it saturates a first-order bound we establish, and logarithmic at strong gate strength. These results expose a general mechanism, first identified here through the cosine gate, by which every finite-order perturbative estimate of a non-Gaussian resource can vanish even though the resource itself remains nonzero. Together, our results establish trigonometric gates as controllable, experimentally realizable building blocks for bosonic
quantum simulation, expanding the class of nonlinear dynamics accessible to continuous-variable
quantum processors.
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All authors Tommaso Rainaldi, Jake Montgomery, Christopher G. Yale, Brian K. McFarland, Melissa C. Revelle, Daniel Lobser, Edward C. Tortorici, Susan M. Clark, George Siopsis, Matt Grau, Felix Ringer
Astrophysics of Galaxies
Investigating anomalous microwave emission near G107.2+5.20 in Ku-band with the Green Bank Telescope
Jordan E. Shroyer, Bradley R. Johnson, Dillon J. Bass et al. (+5 more)
Anomalous microwave emission (AME) is 30 GHz-peaking continuum emission thought to arise from spinning
dust grains. Observations suggest that the local environment shapes the AME spectral energy distribution (SED), so building a spatially resolved sample of AME regions is a key step towards understanding its emission mechanism. Using the Green Bank
Telescope Ku-band receiver, we obtained a ~1 arcmin resolution map of radius 1.25 deg centered on G107.2+5.20. Our first objective was to constrain the low-frequency side of the AME SED with 13 GHz data. Using matched-resolution aperture photometry, we measure the SED from 408 MHz-3 THz and fit two emission models: one including spinning
dust, the other optically thick free-free emission. We find that the spinning
dust model is superior, with an amplitude of $14.1\pm1.1$ Jy and a peak frequency of $27\pm2$ GHz. Our second objective was to spatially locate excess 13 GHz emission consistent with spinning
dust. We compare our Ku-band map to multi-wavelength gas and
dust tracers at ~4 arcmin resolution. We observe two sources of 13 GHz excess at 3$\sigma$ significance consistent with spinning
dust emission, though potential contributions from optically thick free-free emission remain ambiguous. “Region A” (G106.95+5.19) is spatially coincident with peak
dust radiance. “Region B” (G107.08+4.90) is spatially coincident with peak PAH abundance. If regions A and B are indeed sources of spinning
dust emission, they are a resolved example of how AME-
dust correlation varies with environment.
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All authors Jordan E. Shroyer, Bradley R. Johnson, Dillon J. Bass, Anna Dignan, Stuart E. Harper, Brian S. Mason, Andrey Moore, Eric J. Murphy
Quantum Physics
Cluster-configurational study of G-center in Silicon
Narayan Pokhrel, Kyungwha Park and Vsevolod Ivanov
Understanding the properties of defects is imperative for proper use for variety of applications including
quantum computing. In this paper, we use the multiconfigurational self consistent field (MCSCF) combined with DFT optimized geometry in order to investigate the
spin and optical properties of G centers in Silicon. By utilizing
quantum chemistry based methods, we show excellent agreement with the Zero
Phonon Line and Zero Field Splitting Tensor components of the G center. We also calculate the theoretical
spin decoherence time of the G centers using Cluster Correlation Expansion (CCE) methods.
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Quantum Physics
Building Shor's Algorithm in Lean: An Agentic Formalization of Quantum Attacks on RSA-2048 and P-256
Lei Zhang, Yusheng Zhao, Hongshun Yao et al. (+1 more)
Large
language models are increasingly assisting with demanding formal
theorem-proving tasks, particularly when grounded in machine-checked libraries such as Lean. Agentic systems further amplify this process by searching, reusing, and extending existing formal developments to uncover new discoveries. In
quantum computing, Shor's
algorithm and its variants present such a demanding case for Lean formalization. In this work, we formalize this
algorithm family in Lean through agentic formalization: software
agents analyze sources, write Lean code and repair proofs, with human review of the scientific claims and machine checking of the resulting formal proofs. Our formalization develops the mathematical foundations for analyzing
quantum attacks in two cryptographic settings: a 2048-bit modulus in the RSA-2048 and the standardized
elliptic curve over a 256-bit
prime field (P-256). To support these analyses, the formalization ranges from
quantum algorithms for order finding to reversible
quantum circuits for modular and
elliptic-curve arithmetic. Based on [
Quantum 5, 433] and [ASIACRYPT 2017, 241–270], we formalize the logical resource estimates for RSA-2048 and P-256, respectively, and provide additional estimates of classical operations. We expect the results pave the way for broader machine-checked
quantum cryptanalysis and represent a step toward AI-assisted design and verification of
quantum algorithms.
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All authors Lei Zhang, Yusheng Zhao, Hongshun Yao, Xin Wang
General Relativity and Quantum Cosmology
Entropy release from Minkowski breaking in regular Schwarzschild black holes
Francisco S. N. Lobo and Manuel E. Rodrigues
The classical formation of a Schwarzschild black hole from a regular, non-singular configuration has recently been shown to be impossible within general relativity: the geometry inevitably develops a discontinuity at the origin, a phenomenon termed Minkowski breaking by Ovalle, Casadio, and Kamenshchik [PRD 113 (2026), 064042]. This obstruction signals that the transition to the Schwarzschild point mass must be a discrete,
quantum event. We uncover the thermodynamic footprint of this transition. Using the explicit family of regular Schwarzschild black holes with a de Sitter core, we show that the inner Killing horizon carries a formal Bekenstein-Hawking
entropy $S_{\rm inner} = A_{\rm inner}/4$ that is absent in the singular Schwarzschild state. This
entropy is hidden from external observers in
equilibrium but, assuming the generalized second law, must be released when the inner horizon disappears. As the collapse parameter $n$ decreases, the inner horizon shrinks and its
entropy is gradually released during classical
evolution, until the horizon finally vanishes at $n=0$ with the Minkowski breaking. The surface
gravity diverges as $n\to0^+$, with the semiclassical description breaking down at $n \sim 1/\ln(h/\ell_P)$; the final disappearance is therefore a deep
quantum process. For the $n=3$ regular black hole, the stored
entropy is approximately $59\%$ of $A/4$; in the semiclassical limit $n\gg1$, it approaches the full $A/4$. The integer nature of $n$ implies a quantized
entropy spectrum, with the Schwarzschild black hole as the ground state within the OCK family. We discuss how the classical mass-inflation instability may be circumvented by the
quantum disappearance of the Cauchy horizon, and clarify the continuous vs. discrete nature of the collapse.
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Lattice Field Theory
Renormalizing a three-flavor lattice calculation of the two-photon contribution to $K_L\to\mu^+\mu^-$
En-Hung Chao, Norman Christ and Ceran Hu
The Standard Model prediction for the rare $K_L\to\mu^+\mu^-$ decay depends critically on the long-distance contribution coming from the exchange of two
photons. Such a contribution can be computed using
lattice QCD and an effective three-
flavor theory including only the $u$, $d$ and $s$
quarks, provided terms falling as the inverse square of the omitted charm
quark mass, $1/m_c^2$ are neglected. Because of the missing Glashow-Iliopoulos-Maiani cancelation, this three-
flavor theory contains additional low-energy constants that depend on $m_c$. Here we show how these constants can be determined from a practical four-
flavor lattice QCD calculation performed on a small volume with $u$ and $d$
quark masses that are heavier than physical.
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Mesoscale and Nanoscale Physics
Quantum Transport and Apparent Work Function Distributions of Atomic Contacts via a 3D-Printed High-Vacuum Platform
G. Pellicer and C. Sabater
We present a low-cost, 3D-printed high-
vacuum platform integrating a mechanically controllable break-junction system and a custom logarithmic amplifier for room-temperature
quantum transport measurements. Using copper as a highly reactive test case, we successfully resolve the $1G_0$ conductance
quantum under both high
vacuum and anhydrous glycerol, demonstrating the effectiveness of these environments against rapid atmospheric oxidation. In parallel, utilizing gold as a robust
benchmark, we systematically extract the apparent work function ($\phi$) from thousands of tunneling traces across ambient air,
vacuum, and glycerol. Our analysis demonstrates that the statistical distribution of $\phi$ rigorously follows a non-central chi-square distribution. The obtained gold work functions match existing literature across all environments. Although lower than bulk values, they perfectly align with theoretical models accounting for atomic-scale roughness, apex geometry, and environmental adsorbates. Ultimately, this methodology establishes an accessible and reproducible framework for systematic nanoscale research on reactive materials.
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Statistical Mechanics
An exactly solvable macroscopic fluctuation theory of single-file diffusion
Sandeep Jangid, Soumyabrata Saha, Kapil Sharma et al. (+4 more)
Single-file
diffusion is a ubiquitous phenomenon in low-dimensional systems, arising in transport inside narrow channels. Its natural continuum model is a one-dimensional gas of extended Brownian hard rods (BHR). Perhaps owing to the perceived intractability of this problem, much of the literature has traditionally focused on
lattice exclusion models, where integrability methods have yielded remarkable, albeit limited, exact results. A major recent advance comes from a formal solution of macroscopic fluctuation theory (MFT) for the exclusion process. Yet, despite the formal solution, only a handful of properties have been made explicit. We show that the corresponding MFT of the extended BHR gas is in fact exactly solvable through a canonical transformation. We demonstrate this by explicit computation of the large-deviation statistics of the tracer-position and integrated-current in both annealed and quenched ensembles. We further show that an analogous canonical transformation applies to the MFT of
lattice gases with finite-volume exclusion, yielding corresponding tracer and current statistics. We validate our results using rare-event simulations for both the continuum and the
lattice models.
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All authors Sandeep Jangid, Soumyabrata Saha, Kapil Sharma, Jitendra Kethepalli, Benjamin Guiselin, Jacopo De Nardis, Tridib Sadhu
Materials Science
Orbital Hybridization Induces Giant Cubic Rashba Effect at Cu/WO$_{3}$ Interface
Md Aktar Hossain and Saikat Das
Harnessing Rashba
spin-orbit interaction and related spintronic functionalities has traditionally relied on metallic surfaces or interfaces containing elemental heavy metals. Here, using first-principles calculations and Cu(001)/WO$_3$(001) as a model
heterostructure, we show that interfacing a light metal, Cu, with a band
insulator, WO$_3$, yields an interface state that exhibits a robust Rashba
spin splitting arising from the interplay between linear and cubic Rashba effects. The
spin splitting is driven by the strong
spin-orbit coupling of W atoms and enabled by W-Cu orbital hybridization at the interface. The cubic Rashba contribution asymptotically grows with Cu thickness and can be explained in terms of cross-coupling between the
vacuum/Cu and Cu/WO$_3$ interfaces. This interfacial cross-coupling, however, diminishes at larger Cu thicknesses, allowing us to extract the intrinsic cubic Rashba parameter, which has a
giant value of approximately -1.93 eV $\r{A}^3$. In contrast, the linear Rashba parameter is only weakly affected by this cross-coupling and varies from approximately 0.30 to 0.49 eV Å. We further show that sizable linear and cubic Rashba effects persist across several interface geometries and Cu surface orientations, including (110) and (111). Our work identifies the Cu/WO$_3$ interface as a novel light-metal/heavy-element-based
oxide platform for exploring the rich spectrum of Rashba physics, including linear and nonlinear
spin-orbit phenomena.
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Astrophysics of Galaxies
Magnesium isotope ratios in Milky Way and dwarf galaxy stars
M. McKenzie, S. Monty, D. Yong et al. (+8 more)
Under the assumption of hierarchical
galaxy formation,
dwarf galaxies are the closest existing analogues to the high-
redshift protogalaxies that merged to form the Milky Way. These low-mass systems serve as unique laboratories for studying nucleosynthetic channels, given that the chemical compositions of their
stars play a pivotal role in constraining their chemical enrichment history. To date,
stellar abundances in
dwarf galaxies have focused almost exclusively on elemental abundance ratios. While important, elemental abundances omit critical information about the isotopic composition. Here, we compute the Mg isotopic ratios of six accreted
dwarf galaxy stars (low-alpha) and seven Milky Way
stars (high-alpha) using a set of high-resolution (65000 < R < 160000) and high signal-to-noise ratio (S/N > 250) optical spectra. We show, for the first time, that at a given [Fe/H],
stars born in a
dwarf galaxy differ in their Mg isotopic ratios from
stars born in the Milky Way. However, when comparing isotopic ratios at a given [Mg/H] rather than [Fe/H], a powerful diagnostic emerges that suggests nucleosynthesis processes are consistent across different
stellar environments. This universality of Mg isotopic abundances provides additional dimensionality for chemical
evolution models and helps to constrain massive-
star nucleosynthesis across
cosmic time.
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All authors M. McKenzie, S. Monty, D. Yong, C. Kobayashi, A. I. Karakas, P. E. Nissen, J. E. Norris, A. Rains, A. Mura-Guzmán, E. X. Wang, S. Martell
Astrophysics of Galaxies
The complex stellar system M 22: constraining the chemical enrichment from AGB stars using magnesium isotope ratios
M. McKenzie, D. Yong, A. I. Karakas et al. (+8 more)
The complex
star cluster M 22 (NGC 6656) provides a unique opportunity for studying slow
neutron-capture (s-process) nucleosynthesis at low
metallicity due to its two
stellar groups with distinct iron-peak and
neutron-capture element abundances. Previous studies attribute these abundance differences to pollution from 3-6
solar-mass asymptotic
giant branch (AGB)
stars, which produce significant quantities of the
neutron-rich Mg isotopes 25Mg and 26Mg. We report the first-ever measurements of Mg isotopic abundance ratios at [Fe/H] approximately -2 in a globular-cluster-like system using very high-resolution and high signal-to-noise spectra (R = 110000, S/N = 300 per pixel at 514 nm) from the VLT/UVES spectrograph for six
stars, three in each s-process group. Despite the presence of
star-to-
star variations in 24Mg, 25Mg, and 26Mg, we find no correlation with heavy-element abundances, implying that the nucleosynthetic source of s-process enrichment must not influence Mg isotope ratios. Instead, a key result of this work is that we identify correlations between 26Mg/24Mg and some light elements. Using a custom suite of AGB nucleosynthesis yields tailored to the
metallicity of M 22, we find that low-mass AGB
stars of approximately 1-3
solar masses are capable of reproducing the observed s-process abundances of M 22 and that the absence of any difference in Mg isotope ratios between the two s-process groups precludes AGBs with masses above approximately 3
solar masses. This places tighter constraints on possible formation scenarios and suggests an age difference of at least approximately 280-480 Myr between the two populations that is independent of isochrone fitting.
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All authors M. McKenzie, D. Yong, A. I. Karakas, E. Wang, S. Monty, A. F. Marino, A. P. Milone, T. Nordlander, A. Mura-Guzmán, S. Martell, M. Carlos