Cosmology and Nongalactic Astrophysics
Probing inflationary particle production with the CMB power spectrum
Hidde T. Jense, Luca H. Abu El-Haj, J. Colin Hill et al. (+1 more)
Particle production is common to many microphysical models of inflation and can imprint observable features in the
cosmic microwave background (CMB) anisotropies. We consider a scenario in which the inflaton couples to an extremely massive field ($m_\chi \gtrsim \mathcal{O}(100 H_I)$, where $H_I$ is the inflationary Hubble scale). In this model, particle production happens in a burst at a characteristic conformal time, $\eta_*$, which sources localized features in the CMB. In this paper, we compute the full temperature and polarization two-point functions for this model. We then search for these features in CMB power spectrum data from Planck and the Atacama Cosmology
Telescope (ACT), with the latter allowing access to features on smaller angular scales. In the joint analysis of Planck and ACT data, we find a mild $\sim 2 \sigma$ hint for a signal induced by this inflationary model on scales $3 \,\, \text{Mpc}\leq\eta_*\leq 10 \,\, \text{Mpc}$, though this hint is not present at a statistically significant level in either
dataset when analyzed individually. Using a Fisher forecast, we find that these features should be observable at the $3-5\sigma$ level for a Simons Observatory-like experiment, if they are indeed real. We also compare our power-spectrum-based constraints to previous matched-filter-based bounds on this model. For sufficiently light particles ($m_\chi \lesssim 200 H_I$), the power spectrum yields tighter constraints by more than an order of magnitude, but in the higher-mass regime where particle production is rare, the matched-filter approach provides stronger bounds.
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All authors Hidde T. Jense, Luca H. Abu El-Haj, J. Colin Hill, Oliver H. E. Philcox
Instrumentation and Methods for Astrophysics
Characterizing robotic positioners under the influence of changing gravity vectors for future spectroscopic surveys
Johannes Wüthrich, Guandi Zhao, Banan Yamani et al. (+5 more)
Future (Stage V) spectroscopic surveys intend to accurately map billions of
galaxies. To accomplish this goal, these surveys will employ highly multiplexed focal planes composed of robotic fiber positioners to accurately place individual optical fibers on targets of interest. The ambitious science objectives place stringent requirements on the mechanical performance of these positioners. Experience from previous surveys has shown that testing positioners under conditions closely resembling those on the
telescope is of utmost importance during the prototyping and quality assurance phases of construction. We present an automated
telescope simulator test stand that characterizes the performance of these positioners at different orientations, reproducing the changing
gravity vectors encountered during
telescope operations. The test stand aims to verify position stability down to 1 um, focus stability down to 5 um, as well as tilt variations lower than 0.4 deg. We discuss the design of our setup, along with early characterization of image quality due to
turbulence and the compensation of the enclosure deformation via calibration using fixed spots. Finally, we present initial results of positioning stability tests using a prototype module built by Orbray Co., Ltd. This test setup fulfills an important need for integrated testing of advanced focal plane prototypes under conditions similar to on-
telescope conditions.
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All authors Johannes Wüthrich, Guandi Zhao, Banan Yamani, Léonard Lebrun, Sean MacBride, Andrin Fazan, Felipe Andrade-Oliveira, Marcelle Soares-Santos
Solar and Stellar Astrophysics
Investigating the System Configuration of Kepler-451 through Orbital Period Variations: Dynamical and Magnetic Interpretations
Huseyin Er, Aykut Ozdonmez, M. Emir Kenger et al. (+5 more)
We present an analysis of eclipse timing variations in Kepler-451 using data spanning 2004-2024 from both ground- and space-based observations. Using two
datasets, DS-A and DS-B, we constructed updated O-C diagrams. By modeling both
datasets with various LTT configurations, we tested for the presence of circumbinary companions. For DS-A, the two-companion model (LTT34) provides the best fit with RMS = 3.23 s and chi^2_nu = 1.23, while inclusion a fifth body (LTT345) does not improve the fit (RMS = 3.24 s, chi^2_nu = 1.28). For DS-B, the three-companion model (LTT345) yields the best fit (RMS = 2.31 s, chi^2_nu = 1.01), although the semi-amplitude of the inner companion (1.34 s) is smaller than the systematic error (1.81 s), suggesting that it may originate from observational or calibration systematics. Applegate-mechanism tests indicate that most signals exceed the available energy budget, while the outer LTT terms in both
datasets remain consistent with the Standard model and may have a
magnetic origin. Removing these
magnetic terms yields dynamically stable configurations for at least 10^7 yr. These findings support the presence of a second-generation circumbinary
planet at 3.4 AU around Kepler-451, while the origin of the remaining LTT signals remains uncertain.
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All authors Huseyin Er, Aykut Ozdonmez, M. Emir Kenger, B. Batuhan Gurbulak, Ilham Nasiroglu, Murat Tekkesinoglu, Ergun Ege, Nazli Karaman
Astrophysics of Galaxies
Santanu Mondal, Ankit Patel, Mar Mezcua et al. (+5 more)
Feeding and feedback regulated by supermassive black holes (SMBHs) play a central role in
galaxy growth and
evolution, yet these processes remain poorly understood in low-mass
galaxies. In particular, the presence, properties, and role of ultra-fast
nuclear outflows (UFOs) in low-mass
galaxy systems are largely unexplored. We analyze available NuSTAR X-ray observations of Arp 151 and find a possible evidence ($\sim 2\sigma$ confidence) for a fast
outflow with a velocity of $\sim0.18c$ from the central BH. Furthermore, we have also detected an optical
galaxy-scale
outflow in MaNGA Integral Field Unit data. The estimated
nuclear and
galaxy-scale mass
outflow rates are $\sim0.015$ $M_\odot$/yr from NuSTAR and $\sim0.43$ $M_\odot$/yr from MaNGA, respectively. Our estimates suggest that such
outflows may significantly regulate the feedback process in the
galaxy. Comparing the kinetics of the UFO and the
galaxy-scale
outflow indicates that they are in the momentum-conserving phase. This tentative detection implies that
dwarf galaxies are also able to generate UFOs, which so far have been detected in massive
galaxies. Thus, the AGN feedback may also be important for the
evolution of the
dwarf galaxies.
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All authors Santanu Mondal, Ankit Patel, Mar Mezcua, Ravi Joshi, Yerong Xu, K. Aditya, Smitha Subramanian, Victor Rodriguez Morales
Chaotic Dynamics
Emergence of Gamma-Type Upward-Phase Statistics in the Collatz Map: An Effective Poisson Process Mechanism
Weicheng Fu, Xiaobin Liu and Yisen Wang
The Collatz map is a simple deterministic transformation whose orbit structure remains highly nontrivial. A recent direction-phase decomposition partitions each orbit into upward and downward steps, and numerical observations indicate that the number of upward phases, $N_{\uparrow}$, follows an approximate Gamma distribution. In this work, we provide a mechanistic explanation for this statistical regularity by modeling the occurrence of upward phases in the odd-compressed, or Syracuse, version of the Collatz map as a homogeneous Poisson process. From the mean-field logarithmic balance and the
geometric distribution of $2$-adic valuations, we derive closed-form expressions for the Gamma parameters: the scale parameter $\theta = 2/(2-\log_2 3)^2 \approx 11.61$ is constant, whereas the shape parameter $K$ grows logarithmically with the maximal initial value $X_0=2L+1$. We also analyze the closure conditions for periodic orbits, showing that nontrivial cycles are severely constrained, which supports the plausibility of the statistical framework. Numerical validation for $L$ ranging from $10^5$ to $10^{15}$ confirms the theory with relative errors below $3\%$, and a bias-corrected mean estimate reduces the error to $10^{-3}$–$10^{-2}\%$. These results establish a quantitative link between the arithmetic properties of the Collatz map and Gamma-type statistics, and suggest possible extensions to generalized Collatz-type problems.
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Materials Science
Giant and Broadband Circular Dichroism from Particle-Hole Symmetry Breaking in Weyl Semimetals
Xiangyu Jiang, Zeping Shi, Yuhan Du et al. (+14 more)
Circular dichroism originates from
symmetry breaking of material structure, leading to differential absorption of left- and right-circularly polarized light. However, circular dichroism in most materials is inherently weak and spectrally narrow, especially in the mid-to-far infrared. Here, we uncover
giant infrared circular dichroism in the
magnetic-field-forced Weyl semimetal Mn(Bi,Sb)2Te4, driven by extreme particle-hole
symmetry breaking. Helicity-resolved magneto-infrared spectroscopy reveals circular dichroism exceeding 3000 mdeg (~130 mdeg/nm) with above-degree response extending over the 6-13 {\mu}m spectral range. The optical resonances are enhanced by a strong band nesting effect intrinsic to the Landau levels of type-II Weyl dispersion. A
symmetry-based kp model reproduces these magneto-infrared responses and demonstrates that magnetization-induced asymmetric
spin-orbit coupling generates particle-hole
symmetry breaking, suppressing
spin-up, parity-even wavefunction components in the valence Landau band and thereby producing pronounced optical helicity selectivity. Our findings establish particle-hole
symmetry breaking as an effective route toward helicity-resolved optical control in
quantum materials.
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All authors Xiangyu Jiang, Zeping Shi, Yuhan Du, Haonan Chen, Jiayu Wang, Wenbin Wu, Guangyi Wang, Congming Hao, Mingfan Yao, Mingsen Zhou, Xin Chen, Chenyao Xu, Zhongbo Yan, Cheng Zhang, Hai-Zhou Lu, Junhao Chu, Xiang Yuan
High Energy Physics (Phenomenology)
Stochastic gravitational wave spectrum from cosmic string emitting gauge bosons and Majorana fermions
Nobuchika Okada and Osamu Seto
The effect of particle radiation on the spectrum of the
stochastic gravitational wave background (SGWB) from
cosmic strings is studied. We consider
cosmic strings in an Abelian-
Higgs model coupling with Majorana
fermion whose mass is generated by the
Higgs field, motivated by a gauged $U(1)_{B-L}$ model, in which the Majorana
fermions are identified with right-handed
neutrinos. Taking the energy loss by particle radiation into account, we evaluate the resultant SGWB spectrum and demonstrate the emergence of very high frequency cutoff due to the particle radiation.
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General Relativity and Quantum Cosmology
From Holst to Carroll Gravity, a Hamiltonian point of view
J. Fernando Barbero G, Juan Margalef-Bentabol, Valle Varo et al. (+1 more)
The Carrollian regime of
gravity provides a useful ultrarelativistic framework for studying asymptotically flat spacetimes, horizon dynamics, and condensed matter systems. In this paper, we present a comprehensive
Hamiltonian analysis of the most general Carroll-invariant Lagrangian that can be derived from the Holst action. To guide the analysis, Cartan geometry tools are used. We identify the full constraint structure of the theory, characterize its gauge
symmetries, obtain the explicit form of the
Hamiltonian vector fields and introduce Ashtekar-like variables for the
magnetic Carrollian regime. We also discuss in detail an analog of the time gauge employed in the
Hamiltonian analysis of the Holst action for general relativity.
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All authors J. Fernando Barbero G, Juan Margalef-Bentabol, Valle Varo, Eduardo J.S. Villaseñor
Quantum Physics
Nonadiabatic Holonomic Single-Qubit Gates in Non-Hermitian Systems
Wei Li, Yue Zhang, Yu Kun Chen et al. (+1 more)
Holonomic
quantum computation offers a promising route to robust
quantum gates, but decoherence remains a central obstacle in realistic implementations. Here we develop a nonadiabatic holonomic scheme for a driven three-level system in the no-jump regime described by an effective non-Hermitian
Hamiltonian. Within a biorthogonal framework, tailored complex pulses enforce exact closure of the computational-subspace
evolution at the final time despite the underlying nonunitary dynamics, enabling arbitrary single-
qubit holonomic gates without requiring cyclic
evolution in its orthogonal complement. In contrast to existing non-Hermitian treatments, which either neglect the overall exponential prefactor or, in adiabatic settings, include dissipation only on the auxiliary excited level, our scheme incorporates decay and dephasing of all bare eigenstates directly into the pulse design, so that dissipation does not reduce the no-jump gate fidelity.
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All authors Wei Li, Yue Zhang, Yu Kun Chen, Jia Yao Liang
Astrophysics of Galaxies
Validating the ICCF-Cut Method with Simultaneous Photometric and Spectroscopic H$\alpha$ Reverberation Mapping of NGC 4151 and UGC 3374
Chi-Zhuo Wang, Hai-Cheng Feng, Sha-Sha Li et al. (+2 more)
Photometric reverberation mapping (RM) provides an efficient alternative to spectroscopic RM for probing the broad-line region (BLR) sizes in AGNs. In our previous work, we proposed the ICCF-Cut method, which extracts H$\alpha$ emission-line variability from broadband photometric light curves and measures the lags to estimate the BLR sizes. To further assess the reliability of this method, we conduct simultaneous photometric and spectroscopic monitoring of two nearby Seyfert
galaxies, NGC 4151 and UGC 3374, over multiple observing seasons using the Lijiang 2.4 m
telescope. By directly comparing the photometric and spectroscopic RM results in each season, we find that the extracted H$\alpha$ light curves using the ICCF-Cut method closely resemble those derived from spectroscopy. The photometric H$\alpha$ lags are also generally consistent with the spectroscopic H$\alpha$ lags within the uncertainties. For several seasons where the photometric H$\alpha$ lags are slightly underestimated, we find that the discrepancy may be caused by residual He\,i contamination in the extracted H$\alpha$ light curves. After correcting for this contamination, the photometric lag measurements become more consistent with the spectroscopic results. We further explore the performance of the ICCF-Cut method using the simulated light curves with different filter bandwidths. For our observational and simulated cases, the method can successfully recover the emission-line variability and lag measurements broadly consistent with the spectroscopic results. This provides further support for the applicability of the ICCF-Cut method in photometric RM.
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All authors Chi-Zhuo Wang, Hai-Cheng Feng, Sha-Sha Li, Xue-Bing Wu, Qinchun Ma
Atmospheric and Oceanic Physics
Spectral condensation in a finite nonequilibrium atmospheric transition
Dan Zhao, Yongwen Zhang, Teng Liu et al. (+3 more)
Order parameters are difficult to define in high-dimensional nonequilibrium systems that lack a
Hamiltonian, a thermodynamic limit or an observed control coordinate. Here we show that such transitions can be diagnosed from the spectrum of occupations over data-derived eigen-microstates. We combine Eigen Microstate Theory with a Marchenko–Pastur random-
matrix baseline to isolate an emergent sector, whose
entropy quantifies competition among statistically significant collective states. As a finite atmospheric realization, we analyse 51 sudden stratospheric warmings in ERA5. The event-aligned ensemble undergoes spectral condensation, decondensation and recondensation: a polar-
vortex state dominated by a few eigen-microstates gives way to a high-
entropy regime of competing emergent states before selecting a reorganized weak-
vortex state. A
stochastic wave–mean-flow model, in which upward wave-activity flux provides a reduced control coordinate, reproduces the same
entropy maximum, collapse and top-down timing. These results identify emergent-sector
entropy as an order-parameter-like, state-based spectral diagnostic for non-
Hamiltonian transitions and place polar-
vortex breakdown within a broader class of finite nonequilibrium phase reorganizations.
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All authors Dan Zhao, Yongwen Zhang, Teng Liu, Wenqi Liu, Jingfang Fan, Xiaosong Chen
Materials Science
Hydrogen segregation around a straight screw dislocation in bcc iron
Margot Lucas, Marie Landeiro Dos Reis, Sylvain Queyreau et al. (+1 more)
The interaction between hydrogen and screw dislocations in bcc iron is central to understanding hydrogen embrittlement. A major challenge lies in the high-dimensional parametric landscape governing this interaction. In this work, we perform a comprehensive set of molecular simulations using a reliable neural network interatomic potential, systematically exploring hydrogen binding across dislocation core structures (easy and hard cores), site types, and concentrations. From these energetics, we construct a thermodynamic framework that quantifies the statistical relevance of the various trapping configurations, thereby significantly reducing the complexity of the problem. Our results show good agreement with the limited density functional theory data available in the literature. We further delineate the validity domain of an elastic dipole description of hydrogen-dislocation interactions, providing a simplified yet physically grounded modeling approach. Finally, we demonstrate that the easy-core configuration plays a key role in rationalizing experimental hydrogen solubility limits. These findings establish a consistent multiscale foundation for incorporating hydrogen-dislocation interactions into larger-scale models of plasticity and embrittlement.
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All authors Margot Lucas, Marie Landeiro Dos Reis, Sylvain Queyreau, Xavier Feaugas
Space Physics
Magnetic Cloud Boundary Identification Using a Local-Normalized Magnetic Field Parameter
Ziwei Huang, Zhenjun Zhou, Wei Su et al. (+2 more)
Due to the lack of quantitative and reproducible criteria for identifying
magnetic cloud (MC) boundaries, we propose a parameter that characterizes short-timescale variability in
magnetic field strength. The parameter, referred to as the Local-Normalized
Magnetic field parameter (LNM), is defined as $\mathrm{LNM}(t)=\log_{10}\left(B(t)/\langle B \rangle_{\mathrm{5m\text{-}med}}(t)\right)$, where $B(t)$ is the total
magnetic field strength and $\langle B \rangle_{\mathrm{5m\text{-}med}}(t)$ is its 5-minute running median ending at time $t$. This parameter measures the deviation of the
magnetic field magnitude from its local background and reveals a clear contrast between the coherent
magnetic structure inside MCs and the more variable ambient
solar wind. Based on this parameter, we develop a semi-automated method for MC boundary identification, supported by Time Series Scalogram visualization. We further analyze 76 MC events using power spectral density (PSD) and slab fraction diagnostics. The results show that the dissipation-range spectral index inside MCs ($\sim f^{-2.21}$) is systematically smaller than that outside ($\sim f^{-2.59}$ and $f^{-2.89}$), and the slab fraction is reduced, indicating suppressed small-scale variability and enhanced anisotropy. These results support the applicability of the proposed parameter for MC boundary identification.
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All authors Ziwei Huang, Zhenjun Zhou, Wei Su, Yudong Ye, Yuming Wang
Astrophysics of Galaxies
Semi-empirical Predictions for Ultra-deep Radio Counts of Star-forming Galaxies with the SKAO
M. Giulietti, I. Prandoni, L. Bisigello et al. (+4 more)
Star-forming
galaxies (SFGs) dominate the faint
radio sky at flux densities below 0.1 mJy. Identifying these systems through a multiwavelength approach is essential to tracing the
cosmic history of
star formation. Upcoming surveys with the Square Kilometre Array Observatory (SKAO) in its AA4 configuration for the Mid array will probe these faint populations, offering unprecedented insights into the
star formation activity of
galaxies across
cosmic time. Semi-empirical models, built on minimal assumptions and empirical
galaxy relations, provide an efficient framework to study
galaxy evolution using recent
radio and optical/near-infrared (NIR) data. We developed SEMPER (Semi-EMPirical model for Extragalactic
Radio emission) to predict the
radio luminosity functions and number counts of SFGs. SEMPER combines
redshift-dependent
stellar mass functions from deep NIR surveys with empirical relations such as the
galaxy main sequence and the IR/
radio correlation, to characterise the
radio properties of massive, high-
redshift galaxies. The model shows excellent agreement with recent deep
radio observations and naturally predicts a substantial population of massive,
dust-obscured
galaxies already in place at early epochs. In this chapter, we extend the SEMPER framework to SKA surveys by including an evolving starburst fraction and computing differential number counts at 1.4 GHz for both lensed and unlensed SFGs. Furthermore, we predict the
cosmic star formation rate density (SFRD) traced by
radio-emitting
galaxies up to $z\approx10$. Our results show that SKA surveys will probe the faintest flux-density regimes, dominated by
galaxies powered by
star formation, and that <20 hours of SKA-Mid Band 2 observations will recover at least $\approx$20% of the total SFRD predicted by SEMPER, including contributions from optically/NIR-dark systems up to $z\approx 6$.
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All authors M. Giulietti, I. Prandoni, L. Bisigello, M. Bondi, M. Massardi, M. Bonato, A. Lapi
Materials Science
Controlled chemical vapor deposition for synthesis of emerging Mo(W)Te2 systems
Ya Deng, Zi-Yi Han, Yao Wu et al. (+6 more)
The Group-VI transition metal ditellurides offer a rich platform for correlated and topological phenomena, yet their structural polymorphism and instability complicate the creation of single
crystals and heterointerfaces. Here, we introduce a confined-space chemical vapor deposition (CVD) strategy that lowers the growth temperature window and, when combined with tailored precursor configurations and stepwise thermal ramps, enables the deterministic synthesis of high-quality single
crystals,
alloys, and lateral/vertical
heterostructures. High-resolution aberration-corrected STEM provides atomic characterization of
lattice-matched Mo(W)Te2 lateral
heterostructure, revealing nearly atomically sharp, compositionally well-defined seamless boundaries. This approach avoids the thickness nonuniformity and structural limitations commonly associated with exfoliated samples, enabling reproducible fabrication of clean heterointerfaces and establishing a nearly ideal in-situ experimental system. Furthermore, scanning tunneling microscopy and spectroscopy (STM and STS) enable direct imaging of the seamless boundaries in Mo(W)Te2 lateral
heterostructures, while uncovering their distinct real-space distributions of the local density of states. Our results establish a scalable pathway for engineering crystalline Te-based structures with controlled geometry and stacking, providing an essential step toward
quantum and topological device platforms based on the transition metal ditellurides family.
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All authors Ya Deng, Zi-Yi Han, Yao Wu, Kongyang Yi, Ya-Ning Ren, Dundong Yuan, Chao Zhu, Lin He, Zheng Liu
Quantum Physics
Non-Hermiticity of an anomalous superradiant phase
You-Qi Lu, Jun-Ling Wang, Qing-Hu Chen et al. (+1 more)
We present a Hermitian squeezing-Dicke model as a minimal closed-system setting for non-Hermitian many-body physics. Squeezing generates an effective parity-time ($\mathcal{PT}$)
symmetry and exchanges gainy and lossy eigenmodes without dissipation. We identify an anomalous dynamical superradiant phase (DSRP) that exhibits by a mean-field superradiant order in the $\mathcal{PT}$
symmetry-breaking regime, accompanied by a $\mathbb{Z}_2$-
symmetry-breaking ground-state
quantum phase transition. Additionally, it undergoes a $\mathcal{PT}$-breaking dynamical phase transition at an exceptional point (EP). The excitation energy vanishes near both boundaries, giving critical slowing down. The
vacuum photon number is divergent at the ground-state transition but is finite and nonanalytic at the EP, distinguishing the DSRP from the conventional superradiant phase and from a standard dynamical instability. Squeezing causes the coupling phase to act as an artificial
magnetic flux, which yields flux-controlled nonreciprocal
quantum amplification in the DSRP. Our results offer an alternative pathway to non-Hermitian many-body physics and nonreciprocal
quantum amplification in closed Hermitian systems.
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All authors You-Qi Lu, Jun-Ling Wang, Qing-Hu Chen, Yu-Yu Zhang
Chemical Physics
An Iterative Dual-Channel Neural Quantum State Algorithm for Selected Configuration Interaction
Jen-Yu Chang, Yi-Chun Chang, Yu-Jui Lin et al. (+6 more)
Accurately solving the electronic Schrödinger equation for strongly correlated systems remains a central challenge in
quantum chemistry, where the exponential growth of configuration space limits the applicability of exact methods. Selected Configuration Interaction (SCI)
algorithms address this challenge by adaptively constructing compact determinantal expansions, yet their efficiency depends critically on the quality of the sampling strategy used to identify chemically important configurations. Here we introduce the Handover Iterative Neural
Quantum State (HI-NQS)
algorithm, which embeds a classically trained autoregressive
Transformer neural
quantum state within the iterative sample–diagonalize–update framework of Sample-Based
Quantum Diagonalization. A dual-channel
Transformer architecture with explicit
spin-up/
spin-down cross-
attention encodes fermionic
spin structure as an architectural inductive bias, enabling expressive and physically informed wavefunction representations. After each subspace diagonalization, the resulting eigenvector is distilled back into the network through a factorized
spin-marginal teacher signal, establishing a closed feedback loop between generative sampling and exact diagonalization.
Benchmarks across a range of small molecules and a systematic nitrogen active-space series demonstrate that HI-NQS achieves chemical accuracy on all systems tested, with determinant-count scaling substantially more favorable than conventional CIPSI-based SCI for all but the smallest active spaces. All calculations are performed on GPU hardware without
quantum computing resources, establishing HI-NQS as an efficient and scalable purely classical approach to the selected configuration interaction problem.
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All authors Jen-Yu Chang, Yi-Chun Chang, Yu-Jui Lin, Ming-Chun Yang, Hsiu-Chi Tsai, Tai-Yue Li, Nan Yow Chen, Tsung-Wei Huang, En-Jui Kuo
High Energy Physics (Phenomenology)
Magnetic moments of decuplet baryons in isospin asymmetric magnetized strange matter
Hrishika P, Manpreet Kaur, Suneel Dutt et al. (+2 more)
We investigate the in-medium masses and
magnetic moments of decuplet
baryons $(\Delta,\Sigma^*,\Xi^*,\Omega^-)$ in isospin asymmetric magnetized strange matter at finite temperature within a unified
chiral effective framework. Medium modifications of
baryons are implemented using the
chiral SU(3)
quark mean-field (CQMF) model, where constituent
quarks interact via scalar ($\sigma$, $\zeta$, $\delta$) and vector ($\omega$, $\rho$, $\phi$)
meson fields considering the Dirac sea effects. The external
magnetic field is incorporated through Landau quantization of charged particles together with anomalous
magnetic moments (AMM) of
baryons. The resulting in-medium mass of constituent
quarks and decuplet
baryons obtained from the CQMF model are subsequently employed as input to the
chiral constituent
quark model ($\chi$CQM) to evaluate
magnetic moments of
baryons. Contributions from valence
quarks, sea
quark spin polarizations, and orbital angular momentum of the
quark sea are taken into account. Our results provide a systematic understanding of how dense, hot, and magnetized environments influence the
magnetic properties of decuplet
baryons.
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All authors Hrishika P, Manpreet Kaur, Suneel Dutt, Harleen Dahiya, Arvind Kumar
Astrophysics of Galaxies
NO molecule in massive star forming regions
Shaomin Su, Junzhi Wang, Rui Luo et al. (+7 more)
Context. Among diatomic molecules composed of the abundant elements C, N and O, NO has been detected far less than the well studied CN and CO, making it a crucial yet under-observed component in nitrogen-containing chemical networks. NO was thought to serve as a potential tracer of shocks, as evidenced with orders abundance enhancements reported in literature. Aims. Large-sample observations for NO molecule in widespread interstellar environments are needed to confirm if the enhancement of NO is due to shock chemistry or not. Methods. Single-point survey for NO lines around 150 GHz was carried out by Arizona
Radio Observatory 12-meter
telescope towards a sample of 36 massive
star forming regions containing SiO emission, which include three evolutionary stages: 4 IRDCs, 6 protostars and 26 H II regions. Results. The NO emission was detected in 28 sources with a detection rate of 78%. Beam-averaged NO column densities and abundances relative to H2 were derived from integrated intensities of two main hyperfine lines. Correlations between NO and SiO in integrated intensity and relative abundance are similar to the corresponding correlations of c-C3H2, indicating that NO enrichment may not significantly involve pronounced shock activities, which coincides with the trend in line widths: NO is close to c-C3H2, both smaller than H2CO and far smaller than SiO. Conclusions. Observational evidence does not strongly support significant NO enhancement by shock chemistry in the observed sources, indicating that the formation of NO does not necessarily require shocks.
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All authors Shaomin Su, Junzhi Wang, Rui Luo, Yani Xu, Fu Mo, Yijia Liu, Chang Ruan, Yingxue Kang, Yuqiang Li, Siqi Zheng
High Energy Physics (Phenomenology)
Global analysis of a minimally extended scotogenic model
Huchan Lee and Sin Kyu Kang
We perform a global analysis of a minimally extended scotogenic model motivated by observed non-zero
neutrino masses, viable dark matter (DM) candidates, and the instability of the Standard Model (SM)
vacuum at high-energies. We examine the bounded-from-below conditions,
vacuum stability, and RG-driven perturbativity bounds arising from the extended scalar sector, alongside a comprehensive set of
flavor and electroweak (EW) precision observables - including the
muon anomalous
magnetic moment $\Delta a_{\mu}$, the radiative decays $\ell_{\alpha} \rightarrow \ell_{\beta} \gamma$ and $\ell_{\alpha} \rightarrow 3\ell_{\beta}$, and the $\mu \rightarrow e$ conversion rate, the oblique parameters, and leptonic decays of $Z$ and $H$
bosons. A numerical scan reveals four notable features: the DESI BAO bound would rule out the inverted hierarchy if confirmed by other experiments; the oblique parameters are projected to be within the reach of future precision measurements; the viable fermionic DM candidate mass lies in the range $120-350 \operatorname{GeV}$, while the CP-odd scalar is constrained to $350-600 \operatorname{GeV}$; and our result on $Z \rightarrow \operatorname{Invisible}$ is compatible with the world average at the $3\sigma$ level and is favored by the recent ATLAS measurement at the $3\sigma$ level.
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Optics
Giant Second-Harmonic Generation in 3R-MoS2/MLM Hybrid Metasurfaces Cavities
Omar A. M. Abdelraouf
Nonlinear 2D materials such as 3R-phase molybdenum disulfide (3R-MoS2) offer strong second-order optical nonlinearities in an atomically thin platform, making them attractive for on-chip frequency conversion,
quantum light generation, and integrated nonlinear nanophotonics. However, the second harmonic generation (SHG) efficiency of monolayer or few-layer 3R-MoS2 deposited on planar substrates remains fundamentally limited by weak light-matter interaction, poor phase matching, and small interaction volumes. Here, we introduce NanoPhotoNet-PINL, a physics informed AI-driven inverse design framework based on a hybrid one-dimensional convolutional neural network and deep neural network autoencoder, tailored for nonlinear MLMs metasurfaces. The model directly maps target dual-resonant reflection spectra at the fundamental and second-harmonic wavelengths to the required multi-layer geometries and material compositions that maximize the effective nonlinear overlap with an embedded 3R-MoS2 sheet. By integrating Maxwell-based nonlinear electrodynamics into the inverse design loop, we compute the second-harmonic conversion efficiency and modal overlap factors for each predicted MLMs design, enabling physics-guided training and evaluation. Our approach achieves an inverse-design prediction efficiency exceeding ~99.2 % along the linear spectral
manifold, while the optimized dual-resonant MLMs yield more than three orders of magnitude enhancement in SHG intensity compared to a bare 3R-MoS2 flake on a planar substrate. NanoPhotoNet-PINL establishes a generalizable paradigm for intelligent inverse design of nonlinear multi-layer metasurfaces and phase-matched dual-resonant cavities for high-efficiency second-order processes.
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Statistical Mechanics · Cross-listed from cs.IT
Grouped Reverse Importance Sampling for the Partition Function
Neri Merhav
We introduce and analyze several grouped variants of the method of reverse importance sampling (RIS) for estimating a partition function from samples of the Boltzmann distribution $p(x)=e^{ \betaU(x)}/Z(\beta)$. Ordinary RIS weighs each sample separately. By contrast, our proposed grouped RIS (GRIS) methods are based on assigning the samples into groups (or batches) of size $k\ge 2$ and applying a joint weight function to each group. The focal point of the research is the quest for a tractable weight function that would yield the smallest possible mean squared error (MSE). A simple identity relates the normalized MSE to the chi-squared divergence between the joint-weight distribution and the distribution of the $k$-fold sum of independent energies. Our first theoretical finding is that any weight that improves on ordinary RIS ($k=1$) must couple the group components. In other words, it must not be a product-form function across those components, as product-form weight functions always worsen the MSE. Our second, and more important, finding is that, without loss of optimality, it is sufficient to seek weight functions that depend only on the total energy, $\sum_iU(x_i)$, of the group (group-energy weight functions); for the sliding-window variants, the analogous result is open. This finding simplifies both the theoretical analysis and the application of the method substantially. For $k=2$ and $k=3$, the MSE associated with non-overlapping (NOL) groups is reduced by $20$–$65\%$ across three examples. We then propose two additional variants of GRIS, both based on sliding-window grouping (as opposed to NOL grouping). The first applies a fixed weight sliding window (FSW) across all (cyclic) shifts of the sliding window, and the second allows a variable-weight sliding window (VSW). The FSW scheme improves on the NOL one, and the VSW improves even further, as will be demonstrated numerically.
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Astrophysics of Galaxies
SKA VLBI survey of the Southern sky for astrometry, geodesy, and astrophysics
M. H. Xu, L. Y. Petrov and Y. Y. Kovalev
The development of SKA will open the opportunity to run dedicated VLBI surveys of the Southern sky and observe sources not visible at
radio telescopes located in the Northern hemisphere. These surveys will allow for doing geodesy with a Southern hemisphere-centered network, increase the density of compact
radio sources that can be used as calibrators, further extend the celestial reference frame to deep south, and facilitate high-precision differential astrometry for a wide range of applications. Achieving a deep completeness level and determining the parsec-scale properties of extragalactic
radio sources is crucial for multi-wavelength and multi-messenger astrophysics. This includes supporting Cherenkov and
neutrino telescope science cases, as well as joint VLBI-
Gaia studies of active
galaxies.
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High Energy Physics (Phenomenology)
Coherent collective response in many-qubit systems for dark matter detection
Ryuichiro Kitano and Ryoto Takai
We propose an array of Ramsey-type interferometers using $N$ superposition states, $(\vert 0 \rangle + \vert 1\rangle)^{\otimes N}$, as a sensor to detect wave-like dark matter. After exposure to the dark matter wave, which induces coherent
qubit transitions, the signal is the imbalance between the numbers of 0 and 1 outcomes. The signal-to-noise ratio in this scheme is proportional to $N \alpha^2$, where $\alpha$ is the coupling of dark matter to the
qubits, and thus the sensitivity to the coupling scales as $\delta \alpha \sim 1 / \sqrt{N}$. For comparison, in the detection scheme based on the Rabi-type transition, $\vert 0 \rangle \to \vert 1\rangle$, this scaling is achieved only when $N$ highly entangled
qubits are used. Since the Ramsey-type measurement does not require entangled states, one can consider much larger $N$ by simply placing a large number of
qubits within the de Broglie wavelength of the dark matter. We demonstrate that, using trapped-ion
qubits in linear Paul traps as the sensor, the projected sensitivity to the coupling matches or surpasses existing laboratory, astrophysical, and cosmological bounds for $N \gtrsim 10^6$-$10^8$. We also evaluate its sensitivity to high-frequency gravitational waves. Our general framework should, in principle, be useful for other
quantum sensing platforms.
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Adaptation and Self-Organizing Systems · Cross-listed from q-bio.NC
Surviving by Serving: Functional Relevance Drives Self-Organization in Complex Adaptive Systems
Claus Metzner, Ali Ghebleh, Achim Schilling et al. (+3 more)
Complex adaptive systems often develop organized structures without centralized control. Yet the local mechanisms by which functional organization emerges and persists remain incompletely understood. Here we propose Surviving by Serving (SBS) as a general principle of self-organization: components persist as long as their outputs are utilized by other components, whereas prolonged non-utilization promotes adaptation and exploration. To investigate this idea, we introduce a minimal multi-
agent model in which
agents transform shared resources and receive only local feedback when their outputs are subsequently utilized elsewhere in the system. Despite the absence of global objectives, the system spontaneously self-organizes into functional interaction networks. We observe the emergence of stable transformation chains, core-periphery organization, and the generation of novel states that enable previously inaccessible target conditions to be reached. Remarkably, self-sustaining interaction networks can arise even without external selection pressures, creating a pre-adaptive search phase from which later functional solutions emerge. These findings suggest that functional utilization may provide a simple, substrate-independent mechanism for the emergence and stabilization of organized structure in complex adaptive systems.
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All authors Claus Metzner, Ali Ghebleh, Achim Schilling, Andreas Maier, Thomas Kinfe, Patrick Krauss
Instrumentation and Detectors
Development and Characterization of Low-Scattering Vanadium Nanoparticle Targets for Short-Range Interaction Searches
Masayuki Hiromoto, Tatsushi Shima, Christopher C. Haddock et al. (+8 more)
We developed high-purity vanadium-based nanoparticle targets for
neutron scattering experiments aimed at exploring
gravity-like short-range new interactions in the submicron regime. Vanadium and V-Ni nanoparticles were fabricated using top-down and bottom-up methods and quantitatively characterized by SEM-EDS, ICP-AES, NDIR and SAXS. Through the performance tests, an RF thermal
plasma method was found to be the best from viewpoints of the reproducibility, dispersion of the radius, and contamination of metallic elements. The oxygen incorporation during fabrication was quantified, and its impact on the effective coherent scattering length was evaluated, leading to a minimum average coherent scattering length of $\mathrm{0.719(23)\,fm}$, comparable to that of natural vanadium. These results demonstrate that vanadium-based nanoparticle targets with controlled composition and nanostructure can be systematically designed and fabricated to suppress
nuclear scattering backgrounds, thereby enabling experimentally viable coherent
neutron scattering measurements for short-range interaction searches.
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All authors Masayuki Hiromoto, Tatsushi Shima, Christopher C. Haddock, Katsuya Hirota, Masaaki Kitaguchi, Ryota Kondo, Rintaro Nakabe, Kenji Mishima, Hirohiko M. Shimizu, Yuki Yoshikawa, Tamaki Yoshioka
Chaotic Dynamics
One-shot prediction of noise-induced bifurcations with reservoir computing
Nozomi Akashi, Takayuki Watanabe, Masato Hara et al. (+4 more)
Dynamical systems can exhibit complex responses when noise is injected. In particular, dynamics can be qualitatively altered by dynamic noise, a phenomenon known as noise-induced bifurcation. Predicting noise-induced bifurcations is a critical challenge in nonlinear physics. Recently, it has been reported that reservoir computing, a machine learning framework, can reconstruct the unseen global structure of a dynamical system, including bifurcations, from limited time series data. However, learning global structures in random dynamical systems has not yet been systematically addressed. In this study, we report that a simple reservoir computing framework can predict the noise-induced bifurcation structure from the time series at a single noise condition. We demonstrate dynamic noise cancellation and the reconstruction of entire noise-induced bifurcation structures, including noise-induced chaos and noise-induced order, in representative dynamical systems. Additionally, we provide a theoretical explanation for noise cancellation and demonstrate noise cancellation of a neuromorphic spintronics device. Our results provide significant insights into understanding and harnessing real-world noisy complex dynamics.
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All authors Nozomi Akashi, Takayuki Watanabe, Masato Hara, Takao Namiki, Hiroshi Kokubu, Ichiro Tsuda, Kohei Nakajima
Soft Condensed Matter
Solid-to-solid transition in dense assemblies of elongated cells
Shao-Zhen Lin and Jean-François Rupprecht
Cell shapes in confluent tissues range from nearly isotropic epithelial morphologies to highly elongated endothelial ones. In standard vertex models, tissue
rigidity is controlled by a target shape index; increasing this index drives
cell elongation and ultimate tissue fluidization. Here, we consider the case where
cell elongation emerges autonomously by assigning an intrinsic, passive elastic preference for anisotropic shape. This distinction reverses the usual expectation:
cell elongation does not fluidize the tissue, but drives a solid-to-solid transition from an ordered isotropic solid to a disordered anisotropic solid, with finite yield stress and shear
rigidity on either side of the transition. These results decouple
cell shape from tissue rheology and caution against inferring fluid-like mechanics from elongated
cell morphologies alone.
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Optics · Cross-listed from cs.AI
Socratic agents for autonomous scientific discovery in high-dimensional physical systems
Xianrui Zeng, Pengfei Liu, Yirui Zang et al. (+5 more)
The automation of scientific discovery has reached an inflection point. While AI systems now operate instruments, optimize parameters and generate hypotheses, most remain procedural: they execute workflows fixed by human designers. True autonomous science demands epistemic autonomy–the capacity to construct, challenge and revise physical explanations in response to evidence. Here we introduce AHOIS, a multi-
agent AI scientist that embeds Socratic midwifery into closed-loop experimentation. A physics-critic
agent interrogates hypotheses through causal questioning, constraint checking, counterexample generation and falsification-criteria formulation. We evaluate AHOIS on a real multimode-fibre optical platform, a high-dimensional system with complex wave transformations, indirect detection, environmental drift and multi-modal acquisition. Without prior encoding schemes, classifiers or speckle models, the system autonomously proposed and validated a random-interference encoding hypothesis, discovered task-adaptive sparse-measurement strategies, diagnosed distinct failure modes (encoding instability, fluorescence contamination and detector noise) and translated a published imaging protocol into an executable workflow on a non-original configuration. The discovered encoding yielded 16x16 measurements with effective rank 56.9 and classification accuracies of 76.97% on MNIST and 83.17% on Fashion-MNIST. Ablations show that Socratic interrogation improves physical consistency, hypothesis completeness, uncertainty calibration and experimental-plan validity. These results establish a route from workflow automation towards evidence-grounded, self-correcting autonomous discovery in complex physical environments.
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All authors Xianrui Zeng, Pengfei Liu, Yirui Zang, Yang Shen, Fei Yu, Chunlei Yu, Minghao Liu, Yang Du
High Energy Physics (Phenomenology)
RG Running of Multiple Neutrino Mixing Parameters at Oscillation Experiments
Peter B. Denton, Shao-Feng Ge, Chui-Fan Kong et al. (+1 more)
If the new physics scale is within the energy scale of
neutrino oscillation experiments, it may lead to a renormalization group (RG) running effect between the production and detection processes as well as between different experiments. It is then possible to use multiple
neutrino oscillation experiments to disentangle the multiple RG running parameters. We investigate this effect in a general model-independent sense for a variety of
flavor structures in the context of upcoming experiments DUNE-ND, JUNO-TAO, and FASER$\nu$2 that span a large range in
neutrino energies and many different
flavor combinations. We find strong sensitivity to the running effects of new physics with combination of these experiments, especially the possibility of addressing the non-trivial degeneracies.
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All authors Peter B. Denton, Shao-Feng Ge, Chui-Fan Kong, Pedro Pasquini