Quantum Physics
GWPTools: An extensible Wolfram Language framework for time-dependent Gaussian wave packet dynamics
Jeremy B. Maddox, Ismail Giliani, Carter M. Heck et al. (+1 more)
Gaussian wave packets provide an exact analytical foundation for modeling time-dependent
quantum phenomena, effectively bridging the gap between classical trajectories and full
quantum mechanics. We introduce GWPTools, a highly extensible Wolfram
Language framework designed to compute exact time-dependent Gaussian wave packet dynamics using a unified symbolic-numeric architecture. Built upon a robust “parameter bus” and polymorphic dispatch, the software serves as an interactive pedagogical tool for exploring
quantum theory and an exact algebraic engine for rigorously benchmarking numerical grid-based and trajectory methodologies. Version 1.0.0 focuses on exact time
evolution in driven one-dimensional quadratic potentials. Native extensions into
quantum hydrodynamics and phase space representations enable exact energy decompositions, analytical Bohmian trajectories, and symbolic derivations of quasi-probability distributions and information metrics. We demonstrate the framework's modular scalability by prototyping interference in superpositions, open-system decoherence, and coupled two-dimensional oscillators. Ultimately, these capabilities establish a versatile foundation for maximizing the reach of exact analytical modeling toward increasingly complex driven
quantum systems.
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All authors Jeremy B. Maddox, Ismail Giliani, Carter M. Heck, Connor S. Mattingly
Quantum Physics
Enhanced weak-field sensing using detuned squeezing
Li-Wen Zhang, Yang Liu, Han-Jie Zhu et al. (+1 more)
Achieving measurement precision beyond the standard
quantum limit (SQL) is a fundamental object in
quantum metrology. In this manuscript, we propose a streamlined protocol for weak signal sensing in a trapped-ion
spin-oscillator system that simultaneously exploits detuned motional squeezing and
spin-oscillator
entanglement. By combining these two
quantum resources, the phase accumulation in this
spin system is significantly accelerated, as a result achieving an exponential improvement in the sensitivity over unsqueezed cases. Remarkably, we show that the significant metrological gain provided by our protocol persists in noisy environments, with the sensitivity remaining below the SQL. In particular, our protocol retains a distinct advantage in the short interrogation time regime, thus demonstrating the practical potential in
quantum-enhanced sensing.
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All authors Li-Wen Zhang, Yang Liu, Han-Jie Zhu, Wei Qin
High Energy Physics (Theory) · Cross-listed from math.QA
On quasi-lisse affine vertex algebras $L_{-1-h/6}(\mathfrak{g})$ from rank-one Argyres-Douglas theories
Drazen Adamovic, Xuanzhong Dai and Kaiwen Sun
We study certain simple affine vertex
algebras $L_{-1-h/6}(\mathfrak{g})$ from rank-one Argyres-Douglas theories, where $\mathfrak{g}$ is a non-simply-laced simple Lie
algebra and $h$ is its Coxeter number. For $L_{-3}(F_4)$, we determine the maximal ideal of $V^{-3}(F_4)$, Zhu's
algebra, and the associated variety. We also classify the irreducible highest-weight $L_{-3}(F_4)$-modules and determine the characters of its irreducible ordinary modules. The associated variety is $\overline{\mathbb{O}}_{\widetilde A_1}$, and the level $-3$ is totally collapsing for the orbit $\mathbb{O}_{\widetilde A_1}$. The Poisson coinvariants of the $C_2$-
algebra of $L_{-3}(F_4)$ are isomorphic to $\mathbb{C}[\ell]/(\ell^5)$, where $\ell$ is induced by the conformal vector. Consequently, the characters of ordinary $L_{-3}(F_4)$-modules satisfy a fifth-order modular linear differential equation. We also give modular linear differential equations of orders five and eleven satisfied by the characters of ordinary modules for $L_{-2}(B_3)$ and $L_{-2}(G_2)$ respectively.
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High Energy Physics (Experiment)
New results from electron-positron heavy-flavor factories
Xiaodong Shi
The electron-positron heavy-flavor factories — BaBar, Belle, Belle~II, and BESIII — continue to deliver a broad and sensitive physics program. I report selected highlights presented at ICHEP 2026, covering neutral- and charged-current $B$ processes, tests of lepton-flavor universality in $b\to c\ell\nu$ transitions, precision measurement of Cabibbo–Kobayashi–Maskawa
matrix elements, and
hadron spectroscopy.
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Earth and Planetary Astrophysics
Experimental evidence for physical alteration of fine regolith on near-Sun asteroids
Jooyeon Geem, Mikael Granvik, Georgios Tsirvoulis et al. (+5 more)
The surfaces of airless bodies evolve through processes such as (micro)meteoroid impacts and thermal fatigue, which modify physical properties such as grain size, porosity, and mineral texture. These properties provide clues to surface
evolution and are necessary for interpreting telescopic observations. Near-Sun asteroids (NSAs), which reach heliocentric distances of $\lesssim$0.2 au, are notable targets, as their surfaces are likely modified by intense solar radiation. However, experimental studies of how radiative heating modifies the physical properties of carbonaceous asteroid surfaces remain scarce compared with studies of thermally induced compositional and spectral changes. We investigate these modifications experimentally. Near-Sun conditions at heliocentric distances $0.09<r<0.19$ au are simulated using the Space and High-Irradiance Near-Sun Simulator. CM-type carbonaceous chondrite simulants are irradiated under
vacuum. Brightness is monitored in situ with a
video camera during heating, and morphological changes are examined using a stage microscope and a scanning electron microscope (SEM). The irradiated samples show initial darkening followed by brightening, consolidation, and morphological modifications from sub-micrometer to millimeter scales. The observed brightness modifications are more consistent with changes in the absorption properties of the sample than with variations in surface roughness. SEM imaging of the heated samples shows structures similar to those formed by sintering, which are completely absent in unheated samples. These results suggest that sintering is a likely candidate for the mechanism responsible for the observed consolidation and morphological changes. This work provides experimental evidence to help constrain the surface
evolution of NSAs in general, and supports sintering as a possible mechanism proposed for (3200) Phaethon in particular.
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All authors Jooyeon Geem, Mikael Granvik, Georgios Tsirvoulis, Leonard Schirner, Marianna L. Kemell, Antti Penttila, Axel Hagermann, Athanasia Toliou
Quantum Physics
Nearly Optimal Quantum Sample Complexity of Learning Fourier-Sparse Boolean Functions
Zekun Ye
We study the number of uniform
quantum examples needed to exactly learn a Boolean function with at most $k$ nonzero
Fourier coefficients. We give a learner with near-optimal $\widetilde{O}(k)$ sample complexity independent of the input length $n$. The learner uses only separate measurements of individual examples. This improves the previous $O(k^{3/2}\log^2 k)$ upper bound (Arunachalam, Chakraborty, Lee, Paraashar, and de Wolf, 2021). The main ingredient is a candidate set formed by symmetric differences of subsets from independent groups of
Fourier samples. A multilinear majority
polynomial combines unbiased random approximations into an accurate witness whose
Fourier support lies in this set. Granularity then forces the set to contain the entire
Fourier support, including subsets never directly sampled. For comparison, we derive the tight classical sample complexity $\Theta(nk)$ by combining known sparse-recovery and lower-bound results.
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High Energy Astrophysical Phenomena
The Promise of Gravitational-Wave Astronomy
Parameswaran Ajith
We review the promise of upcoming gravitational-wave (GW) observations in addressing some of the important open questions in astrophysics and cosmology. A decade after the first direct detection of GWs, the field is entering a transformative phase driven by progressive detector upgrades and the anticipated advent of space-based and next-generation ground-based observatories. These instruments will not only push the distance horizon of GW observations to cosmological
redshifts, but will dramatically extend the accessible frequency band, opening entirely new source classes that lie beyond the reach of current detectors. The source landscape is rich enough that surprises are likely. This review surveys our current understanding across this landscape and offers some perspective on the discoveries that upcoming GW observations are poised to deliver.
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Quantum Physics
Toward Interpretable Quantum Generators for Financial Returns through Problem-Informed Circuit Design
Huijie Guan, Xuanhao Wang, Shengbin Wang et al. (+7 more)
When used as function approximators,
quantum circuits often lack interpretability and face a fundamental trade-off between expressivity and trainability. We propose a problem-informed framework for financial return generation that uses relational structure and
symmetry-inspired parameter sharing to guide the construction of
quantum circuits with few trainable parameters and empirically testable operator roles. We evaluate three
quantum generator architectures, referred to as ZZ, directed ZZ-CRX, and structured time
evolution, within a hybrid Wasserstein
quantum generative
adversarial network trained to generate 16-step Bitcoin return windows. Across
circuits with one to four layers and one to eight trainable coefficients, these generators recover meaningful marginal and temporal distributional features, while single-layer configurations remain competitive with deeper variants. Across matched depths, independently trained ZZ-CRX configurations exhibit a predominantly downward shift in median leverage relative to ZZ, consistent with the intended directional role of the controlled-rotation construction. The small number of coefficients also enables direct landscape analysis, revealing competing parameter preferences between marginal and temporal objectives and helping to explain the difficulty of finding parameter settings that perform well on both. These results provide an initial demonstration that structural assumptions can guide the design of compact
quantum generators and link
circuit architecture to observable statistical behaviour, motivating more systematic and parameter-efficient approaches to
quantum circuit construction.
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All authors Huijie Guan, Xuanhao Wang, Shengbin Wang, Jiale Zhang, Jian Ding, Shuxin Xie, Dongdong Li, Jianjian Gao, Hantao Sun, Wenhao Chu
General Relativity and Quantum Cosmology
Exact radial stability threshold for a Minkowski-Schwarzschild thin shell
Anuar Idrissov
We study the stability of a thin shell of ordinary matter that separates a flat interior from a Schwarzschild exterior, which is the simplest model of a subluminal warp drive. The matter content of the shell is fixed by the junction conditions and satisfies all the standard energy conditions except very close to the horizon. For a shell made of causal matter we find an exact radius below which it cannot be stable under radial perturbations. We then place a black hole inside the shell and show that this radius grows with the black hole mass, so that the flat interior is the most favourable case. Since such shells are known to be unstable to non-radial perturbations, our result marks the boundary of the region in which any stabilising mechanism would have to operate.
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General Relativity and Quantum Cosmology
Black holes with dark matter halos and a positive cosmological constant: Energy conditions and signatures
Long-Yue Li, Li-Ming Cao, Yungui Gong et al. (+3 more)
We study static, spherically symmetric black holes surrounded by dark matter
halos in the presence of a positive cosmological constant. Assuming vanishing radial pressure, we derive the constraints imposed by the null, weak, strong, and dominant energy conditions on the
halo matter. The
halo is confined to a finite radial interval separated from both horizons, and the total mass is bounded above by the Nariai value. We construct a Hernquist-type profile and study black hole images, showing that a positive cosmological constant can substantially change the images. We also compute scalar quasinormal modes of the Hernquist-type spacetime. When the dark matter mass is sufficiently small, the relative difference of a selected mode is approximately linear in the compactness of the matter
halo, i.e., the ratio of mass parameter $M_{\text{DM}}$ and scale parameter $a$, with a coefficient that depends on the cosmological constant.
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All authors Long-Yue Li, Li-Ming Cao, Yungui Gong, Xia-Yuan Liu, Liang-Bi Wu, Wenting Zhou
High Energy Physics (Phenomenology)
Octupole parton structure of spin-3/2 targets
Brandon B. Le and Dustin Keller
In
spin-$3/2$ targets, octupole polarization can reveal
quark and gluon correlations beyond those probed by vector polarization and quadrupole
alignment. Here, we construct the complete leading-twist gluon transverse-momentum-dependent distribution basis, with 32 independent coefficients for each specified Wilson-line and color structure. Fourteen of these describe octupole dependence in gluon number, helicity, and linear polarization. In heavy-
quark-pair leptoproduction at small, nonzero pair imbalance, comparing target states with opposite octupoles and identical lower moments isolates the octupole contribution. Beam-helicity reversal and joint angular projections in target orientation and pair-imbalance azimuth can then separate all fourteen gluon octupole responses at leading-power Born order. We also derive the incoming-target
quark responses in semi-inclusive deep-inelastic scattering and Drell-Yan production. Time-reversal relations between distributions remain valid under
symmetry-preserving renormalization and
evolution, while predictions across processes require factorization formulas connecting those distributions to scattering observables. Finally, we connect this framework to polarized $^{7}$Li through its collinear limits and nuclear
spin-orbital correlations.
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High Energy Physics (Phenomenology)
Kernel moments and thermodynamic stability in nonlocal Nambu–Jona-Lasinio models
Xiaozhu Yu and Xinyang Wang
We study thermodynamic consistency and stability in a covariant two-flavor nonlocal Nambu–Jona-Lasinio model at zero chemical potential in the homogeneous
quark mean-field approximation. A controlled large-source expansion gives a sufficient
entropy-sign criterion directly from Euclidean kernel moments, without locating propagator poles. At fixed couplings and kernel, every admissible positive Gaussian mixture develops negative total
entropy at sufficiently large source mass for each fixed positive temperature. In a separate light-source fit to pion observables and a subtracted condensate, one quartic-exponent kernel has positive
entropy and heat capacity for all $T>0$, while $dP/d\epsilon=s/C_V$ exceeds unity on a finite interval. This constructive example separates thermal positivity from the static EOS slope test. Numerical refits show that the enhancement weakens with the condensate input, and a certified counterexample excludes uniform thermal positivity over the adopted matching domain. The results provide diagnostics of the mean-field functional, rather than a preferred phenomenological kernel. Omitted thermal
mesons can change the low-temperature slope test, and the static derivative does not determine a real-time front velocity.
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High Energy Astrophysical Phenomena
Observational evidence of black hole event horizon from ultra-compact X-ray binaries
Qian-Qi Ma, Wei-Min Gu, Shan-Shan Weng et al. (+1 more)
The event horizon is the most crucial feature that distinguishes black hole (BH) from all other objects in the universe. However, since no radiation can escape from the event horizon, its direct observational evidence remains lacking. Although both are compact objects, the event horizon leads to differences in the radiative behavior between black hole and
neutron star (NS) X-ray binaries. Historically efforts to probe the existence of event horizons revealed that the BH X-ray binaries are fainter than NSs with similar orbital periods in their quiescent states. Here, we use a special class of X-ray binaries namely the ultra-compact X-ray binaries (UCXBs), to reveal the existence of the event horizon near stellar-mass black holes. In short-period UCXBs, gravitational radiation dominates the orbital angular momentum loss, allowing us to accurately determine their
accretion rates. Based on five UCXBs with orbital periods shorter than 40 min, located in globular clusters, and identified accretors (NS or BH), we obtained their
accretion rates. Combining their
accretion rates and X-ray luminosities, we calculated the X-ray radiative efficiencies of NS and BH. The radiative efficiency of BH is about two to three orders of magnitude lower than that of NS systems, indicating the
accretion energy is swallowed by the BH, thereby indirectly probe the presence of the event horizon.
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All authors Qian-Qi Ma, Wei-Min Gu, Shan-Shan Weng, Mouyuan Sun
Optics · Cross-listed from eess.IV
Background2Background: a self-supervised background removal framework for high dimensional microscopy
Guangrui Ding, Haonan Lin, Rong Tang et al. (+8 more)
High-dimensional microscopy captures features across space, time, and spectrum, but complex backgrounds obscure signals. We present Background2Background (B2B), a self-supervised background removal framework leveraging the backgrounds larger correlation relative to the signal. Local pixel shuffling disrupts signal correlations while preserving background structure, transforming signals into effective noise for Noise2Noise-based background removal. Across fluorescence, stimulated Raman scattering and mid-infrared photothermal imaging, B2B achieves over 40-fold background suppression and reveals hidden signatures.
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All authors Guangrui Ding, Haonan Lin, Rong Tang, Bethany Weinberg, Jianpeng Ao, Qing Xia, Guorong Hu, Dingcheng Sun, Jiaze Yin, Lei Tian, Ji-Xin Cheng
Quantum Physics
From Syndromes to Computation: A General Framework for Logical Operations in Quantum Error-Correcting Codes
Hunter Nelson, Arshag Danageozian, ChunJun Cao et al. (+2 more)
Fault-tolerant
quantum computation requires error-correcting codes that not only protect
quantum information but also support useful logical operations with practical physical realizations. Here we develop a general framework in which the stabilizer syndromes of commuting Pauli rotations directly organize logical-gate design. We derive an exact codespace-preservation condition valid at arbitrary rotation angles, providing a common stabilizer-level description for CSS and non-CSS codes and for both Clifford and non-Clifford operations. A particularly useful equal-syndrome specialization reduces Clifford gate design to stabilizer factorization, yields a general generator weight bound of $\lceil d/2\rceil$ for distance-$d$ codes, and systematically extends to logical rotations higher in the Clifford hierarchy. Applied to bivariate-bicycle (BB) and non-CSS Mirror qLDPC codes, the framework gives explicit low-weight Clifford and controlled-phase gates. Our implementations yield new low-weight gates, including an addressed $T$ gate on the $[[16,4,4]]$ BB code, $T$-type rotations on the $[[64,8,8]]$ BB code, and CCZ-, CS-, and $T$-type operations on the $[[36,6,6]]$ Mirror code. We also develop analytic constructions using Clifford
algebra bases, which turn the syndrome constraints into explicit algebraic relations and provide a systematic route to logical addressability. We use this approach to analytically construct addressed CNOT, SWAP, controlled, and CCZ-type gates on recursive hypercube codes. An independent construction on middle
quantum Reed–Muller codes yields C${}^r$Z gates that saturate the equal-syndrome weight bound. These results establish stabilizer syndromes as a constructive link between the stabilizer structure of a
quantum code, the logical computations it can directly support, and the fault-tolerance properties of their physical realizations.
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All authors Hunter Nelson, Arshag Danageozian, ChunJun Cao, Sophia E. Economou, Edwin Barnes
Materials Science
A grand potential for molten-salt electrochemical phase diagrams from first principles
Lorenzo Bastonero, Lucio Colombi Ciacchi and Nicola Marzari
The clean-energy transition is driving unprecedented demand for metals, whose extraction is among the largest industrial sources of carbon emissions. Molten-salt electrolysis offers a path toward carbon-free production of aluminum, iron, titanium, and critical metals. However, corrosive operating conditions and complex, multicomponent feedstocks make experimental development costly and challenging. Here, we introduce a first-principles framework for constructing electrochemical phase diagrams of multicomponent systems to accelerate electrode and electrolyte design and guide the selection of compatible materials and operating conditions for electrochemical
cells. We derive a grand potential that generates these diagrams at scale, and supply free energies using first-principles data obtained through a fine-tuned foundation machine-learned interatomic potential. For silicon in molten CaCl$_2$, the construction not only recovers the experimental diagram when using the first-principles framework on a limited set of structures, but also predicts further domains when extended to a larger set of
crystal structures. Finally, we demonstrate the predictive power of the approach by screening ten alkali and alkaline-earth halide electrolytes for aluminum electrowinning. Three thermodynamic criteria identify NaF, where cryolite emerges as the stable aluminum-bearing phase, recovering the chemistry that Hall and Héroult established empirically in 1886. The framework provides a first-principles basis for selecting compatible electrodes, electrolytes, and operating conditions toward low-carbon metal production from complex source materials.
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Quantum Physics
Fast charging of quantum batteries assisted by nonlinear couplings
Y.-J. Shen, Y.-C. Shen, C.-H. Chu et al. (+1 more)
Charger-mediated
quantum batteries offer promising opportunities for efficient energy transfer and storage at the
quantum level, with potential advantages beyond their classical counterparts. Here, we theoretically demonstrate that nonlinear charger-battery interactions can substantially accelerate the charging of
quantum batteries. In the weak-driving regime, sufficiently strong nonlinear coupling can dominate over the effect of dephasing and significantly reduce the charging time. In the strong- and optimal-driving regimes, where the optimal driving strength maximizes the steady-state ergotropy in the linear-coupling regime, nonlinear coupling gives rise to a new optimum in the charging time beyond that of the linear-coupling regime, accompanied by nearly critically damped dynamics. Remarkably, even in the absence of external driving, nonlinear coupling alone can substantially reduce the charging time, providing an alternative route toward fast battery charging. Our results establish nonlinear charger-battery coupling as an effective resource for accelerating
quantum-battery charging and broaden the scope of interaction-enabled
quantum advantages in energy transfer and storage.
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All authors Y.-J. Shen, Y.-C. Shen, C.-H. Chu, H. H. Jen
Fluid Dynamics
Gas radiation and the gravity limit of flicker in a co-flowing hydrogen jet diffusion flame
Tianfang Xie and Meng Wang
Although weak at normal
gravity, gas radiation sets the
gravity at which a co-flowing hydrogen jet
diffusion flame stops flickering. Flamelet-based simulations with unity Lewis numbers, which reproduce the flicker frequency measured by femtosecond coherent anti-Stokes Raman scattering within 4%, are combined with local stability analysis. At one tenth of normal
gravity, the adiabatic flame flickers, the radiating flame does not, and switching the emission off restores flicker. Radiation acts through two mechanisms that do not weaken at reduced
gravity. The hot outer layer loses buoyancy in proportion to the gas residence time, and a disturbance that displaces the flame also displaces its emission, which damps the disturbance on the lean flank (displaced-emission damping). Freezing the radiative source, which removes only its response to disturbances, slows the downstream recession of the oscillation more than tenfold. Both mechanisms slow the upstream spreading of disturbances. This spreading, competing with the co-flow, sets the onset location and the critical co-flow. Without radiation, the spreading speed scales with the square root of
gravity; its radiative reduction does not. At reduced
gravity, the flicker limit therefore becomes a straight line relating the square root of the co-flow Froude number to a radiation number, the ratio of buoyant to radiative time scales. The calibrated line places the critical
gravity for the experimental co-flow at 0.13 times normal
gravity, 2.6 times the adiabatic value. It correctly predicted whether two further flames keep flickering. Beyond the limit, transient wave packets can mimic flicker throughout a short drop-tower test.
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Plasma Physics
Effects of Coulomb Collisions on the Structures of Fast Magnetosonic Shocks
Michael B. Farnell III, Fan Guo, Yi-Hsin Liu et al. (+1 more)
We present fully kinetic particle-in-
cell simulations to demonstrate qualitative effects of binary Coulomb collisions on fast magnetosonic shocks. We find that with sufficiently high collisional frequencies, shock rippling and reformation can be inhibited, leading to stationary, laminar shock fronts. We observe that ion-ion collisions disrupt the motion of particles reflected back upstream that is the key for cyclical reformation. Meanwhile, the electron-ion collisions provide a Spitzer resistivity that can dissipate energy from the instability that causes shock rippling. This result helps us understand the role of collisions in laboratory shocks and possibly the outer heliosphere.
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All authors Michael B. Farnell III, Fan Guo, Yi-Hsin Liu, Xiaocan Li
Quantum Physics
Universal entanglement detection with geometrically optimal witnesses
Xuanran Zhu, Keyi Huang, Chao Zhang et al. (+3 more)
Constructing optimal
entanglement witnesses for arbitrary
quantum systems remains a formidable challenge, hindered by the structural complexity of high-dimensional
quantum state spaces. In this work, we overcome this barrier by introducing a unified framework for constructing geometrically optimal witnesses capable of identifying arbitrary
entanglement structures. By leveraging the
geometric properties of a target
quantum state relative to a specific
entanglement structure in
Hilbert-Schmidt space, these witnesses are constructed in an efficient and effective manner. Among all nontrivial witnesses, they provide maximal distinguishability between the target state and the set of states without the desired
entanglement structure. As a result, our approach enables the universal detection of bipartite, multipartite, and high-dimensional
entanglement. To demonstrate its experimental feasibility, we apply the framework to a four-
qubit nuclear
spin quantum system. Compared to existing methods, our approach offers enhanced noise robustness, broader detection universality, and improved construction efficiency, providing a powerful and versatile tool for advancing the characterization and understanding of
entanglement in
quantum systems.
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All authors Xuanran Zhu, Keyi Huang, Chao Zhang, Xinfang Nie, Qi Zhao, Dawei Lu
Optics
Inverse design of poles and zeros: tailoring phase control in metasurfaces
Junhe Zhang, Seoyoung Kim, Hyun Jung Kim et al. (+1 more)
We develop a physically interpretable inverse-design framework for generalized Huygens metasurfaces, using prescribed scattering poles and zeros to engineer resonance interference and transmission-phase control. Compared with direct optimization of transmission or reflection coefficients, this approach offers a physically transparent route to rationally controlling resonance properties, including linewidth and group delay, while reducing computational cost. The resulting designs demonstrate how near-unity transmission and $2\pi$ phase excursion can arise from resonance interference. These signatures of the Kerker effect extend beyond the conventional
alignment of electric and
magnetic dipole resonances to other mechanisms, including guided-mode resonances and quasi-bound states in the continuum. We further optimize the Kerker condition across a continuum of refractive-index states in a reconfigurable phase change material metasurface, enabling high-transmission $2\pi$ phase tuning. Our results establish a versatile and practical approach to metasurface phase control through the targeted design of scattering poles and zeros.
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All authors Junhe Zhang, Seoyoung Kim, Hyun Jung Kim, Juejun Hu
Quantum Physics
Coherent optical control of a thousand qubits in a three-dimensional trapped-ion crystal
Yue Li, Yuxiang Huang, Yi Li et al. (+8 more)
Leading
quantum platforms are largely limited to one or two dimensions, whereas three-dimensional Coulomb
crystals of trapped ions self-assemble into dense
qubit arrays with no rearrangement overhead. Coherent optical control of such
crystals has nonetheless been out of reach, because the optical transition couples to nearly all $3N$ collective modes, i.e., a thermally occupied quasi-continuum bath. Here we cool about 3,600 modes of a
crystal of over 1,200 ions below single-
phonon occupation, using a continuous cooling band that spans more than five octaves in vibrational spectrum, from about 50 kHz to 2.1 MHz. The
crystal then serves as a register of optical
qubits, allowing global initialization, coherent manipulation and collective detection. We demonstrate ensemble optical coherence of 21.6 milliseconds and reduce the optical-transition frequency uncertainty from 389 Hz for a single ion to 12 Hz for over a thousand ions, approaching the expected projection-noise scaling. Our approach could be extended to even larger
crystals with
phonon-mediated many-body couplings, opening a route towards
entanglement-enhanced precision metrology and three-dimensional
quantum simulation, particularly with spatial-shaped illumination for region-resolved collective control.
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All authors Yue Li, Yuxiang Huang, Yi Li, Xu Cheng, Zihan Xie, Qingyuan Mei, Chang-Ling Zou, Ya Wang, Xinhua Peng, Yiheng Lin, Jiangfeng Du
Astrophysics of Galaxies
Non-equilibrium chemistry and radiation hydrodynamics in metal-poor and metal-rich interstellar gas
Shyam H. Menon, Piyush Sharda, Blakesley Burkhart et al. (+1 more)
We present a flexible implementation of non-
equilibrium chemical networks with the $\texttt{KROME}$ framework, coupled to a nonlocal variable Eddington tensor-closed radiation transport scheme ($\texttt{VETTAM}$). Our fiducial network is designed to explicitly capture the formation pathways of important molecular species such as CO, OH, and $\rm H_2O$, intermediaries like $\rm H_3^+$, and the destruction of these species through
photon and
cosmic-ray dissociation. We validate our scheme through
benchmark tests, and demonstrate its success in 1D and 3D problems covering a broad range of
metallicities ($0 \leq Z \lesssim \rm Z_{\odot}$) and densities ($n \lesssim 10^{17} \, \rm cm^{-3}$). We confirm earlier works that suggest that OH and $\rm H_2O$ are the key molecular species in dense gas ($n \gtrsim 10^{5} \, \rm cm^{-3}$) for $Z\lesssim 0.01 \rm Z_{\odot}$, dominate the cooling at these densities, and demonstrate that our scheme can reproduce their abundances with similar accuracy as dedicated static photo-dissociation region (PDR) codes. We also find that the dominant fine-structure coolant in dense ($n \gtrsim 10^3 \, \, \rm cm^{-3}$) PDRs transitions from CI to CII to OI at increasingly lower $Z$. Finally, we find that in turbulent media, rapid mixing at PDR interfaces renders the chemical species out of
equilibrium, and show that this could potentially alleviate the long-standing problem of (static) PDR models producing excess CI in the diffuse ISM over UV absorption-line measurements. We conclude by presenting and comparing with alternative implementations of reduced but faster chemical networks in our scheme, discussing the problem-dependent performance-accuracy tradeoffs and future prospects.
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All authors Shyam H. Menon, Piyush Sharda, Blakesley Burkhart, Tommaso Grassi
Astrophysics of Galaxies
Mergers may not be the main channel for galaxy stellar mass growth at redshift $z\gtrsim5$: Predictions from cosmological hierarchical models and simulations
Hao Fu, Mohammadreza Ayromlou, Francesco Shankar et al. (+13 more)
Mergers are a crucial channel of
galaxy growth, but their role relative to
star formation remains uncertain at high
redshift. Here we investigate merger rates and merger-driven stellar mass assembly for
galaxies with stellar mass $M_\star \gtrsim 10^8 \, {\rm M_{\odot}}$ at $z\simeq 5-11$, by combining complementary theoretical approaches within $\Lambda$CDM. These include the DECODE semi-empirical model, the TNG100 and EAGLE hydrodynamical simulations, and the L-
Galaxies semi-analytical model, together with the Millennium and TNG100-Dark simulations used to examine dark matter subhalo statistics and merger timescales. This compares models with different treatments of baryonic physics and
galaxy-
halo connections. We find that dark matter-only simulations predict merger timescales $\sim 30\%$ longer than those inferred from cosmological simulations including baryons.
Galaxy major merger ($M_{\rm \star,sat} / M_{\rm \star,cen} > 0.25$) rates are high at
cosmic dawn and increase towards earlier epochs, reaching $\sim 1/{\rm Gyr}$ at $z\sim 5$ and peaking at $\sim 3/{\rm Gyr}$ at $z\sim 8$. Despite these high rates, mergers contribute only $\lesssim 10\%$ of the total
cosmic stellar mass density
evolution. The ex-situ stellar mass fraction ranges from a few percent to $\sim 20\%$ for all
galaxies at $z\gtrsim 5$, across different models and simulations. Their broad agreement implies that stellar mass assembly at
cosmic dawn is dominated by in-situ
star formation rather than mergers. These findings suggest that the high pair fractions identified by JWST may not directly trace efficient ex-situ stellar mass growth, highlighting the need for physically motivated merger timescales to interpret
galaxy assembly in the early Universe.
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All authors Hao Fu, Mohammadreza Ayromlou, Francesco Shankar, Lars Hernquist, Andrea Lapi, Daniel Roberts, Feng Yuan, Maulik Bhatt, Evgenii Chaikin, Simona Gallerani, Luca Graziani, Antonio La Marca, George Mountrichas, Yingjie Peng, Haocheng Wang, Kai Wang
Earth and Planetary Astrophysics
Elastic Properties of Titan Tholins Revealed by Brillouin Spectroscopy
Mark A. Johnson, Jose R. Montes-Bojorquez, Adis Husic et al. (+7 more)
Titan tholins, complex organic solids synthesized by simulating photochemical processes in Titan's atmosphere, are widely regarded as analogs to organic surface materials on the Saturnian moon. Their mechanical properties are critical for understanding the
evolution of Titan's geomorphology and crustal layering. Here, we report the first direct experimental determination of the complete set of aggregate elastic moduli of tholins using Brillouin spectroscopy. Measurements conducted on tholin powder samples yielded a bulk modulus of 11 (2) GPa and a shear modulus of 3.9 (5) GPa, from which we derive a Young's modulus of 11 (1) GPa and a Poisson's ratio of 0.34 (3). Thin-film samples synthesized under slightly different conditions yield similar results. Compared with other Titan-relevant organic compounds, tholins exhibit the highest elastic stiffness measured to date, exceeding even H2O ice in both bulk and shear moduli. These results support the interpretation that complex organics contribute significantly to the mechanical stability and transport behavior of Titan's equatorial dune sediments. Measurements following prolonged atmospheric exposure reveal persistent stiffening of tholins that remains after
vacuum treatment, likely associated with minor chemical modification and physical reorganization, highlighting the importance of controlled sample handling for future laboratory investigations. This study also demonstrates the effectiveness of Brillouin spectroscopy as a non-destructive technique for characterizing planetary organic materials and provides new constraints relevant to future seismic and geophysical investigations by the Dragonfly mission.
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All authors Mark A. Johnson, Jose R. Montes-Bojorquez, Adis Husic, Xinting Yu, Wenhao Su, Jia-Sen Hu, Ryan Blase, Edward Patrick, Alan Whittington, Jin S. Zhang
Atmospheric and Oceanic Physics
The hypervariational method: a general, automated technique based on innovations to tune the parameters of the Hybrid covariance matrix
Francesco Sardelli and Craig H. Bishop
The Hybrid forecast covariance model is an operationally successful way to build a background error covariance
matrix. It is constructed as a weighted sum, with scalar weights, of the climatological covariance
matrix and a localized ensemble covariance
matrix, with a localization
matrix typically depending on a localization length. For best performance, the Hybrid needs to be optimized by tuning those weights and, possibly, other parameters, such as the localization length. Here, a systematic and automated method for this tuning operation is introduced. This technique is referred to as hypervariational method, and it is formulated in terms of a cost function, built using a time series of innovations as an essential ingredient. This cost function, which depends on the parameters, is minimized when they have optimal values. Equations for its minimization, based on Newton's method, are derived. Besides the aforementioned, commonly used Hybrid, the hypervariational method is applicable to any known Hybrid (and to any set of parameters on which it depends analytically), including recently developed Hybrids, not necessarily constructed as weighted sums. Here, the hypervariational method is applied to tune the ensemble covariance
matrix weight in the seminal-formulation Hybrid (which does not feature localization). This is done in a synthetic experimental setting where a theoretically-derived expression for the optimal value for that weight is known. Moreover, in that experimental setting, a further method, based on a linear fit procedure, to determine that optimal value is possible. Both the hypervariational method and that linear fit procedure are shown to produce an optimal weight value matching (up to a tolerance of $0.1$) the optimal value known from the theory. Furthermore, Newton's minimization in the hypervariational method is shown to converge immediately (at the first recursive step).
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Astrophysics of Galaxies
A radio counterpart of the local little-red-dot J092359+415736
Tao An, Ruqiu Lin and Ailing Wang
Little red dots (LRDs) are compact red sources at z>~4. Broad lines suggest accreting black holes, yet
radio and X-ray measurements are usually weak. Local LRDs allow multi-frequency, multi-epoch
radio studies that are inaccessible at high
redshift. We search archival
radio images for a counterpart to the local LRD J092359+415736 at z~0.323, quantify its long-term
radio variability, and identify the plausible origin of the
radio emission. Flux densities at the optical position are measured in FIRST, LoTSS, RACS, VAST, and VLASS products spanning 0.144-3.0 GHz and 1994-2024. A compact 144 MHz counterpart is detected at 42sigma in LoTSS, coincident with the Gaia position, and is recovered in FIRST, RACS, VAST, and VLASS. LoTSS and ASKAP give a spectral index alpha ~ -0.30 +/- 0.11. The source varies on multiple timescales: FIRST at 1.4 GHz (1994) is a factor of ~2.6 below ASKAP (2021-2024) and below the extrapolated LoTSS-ASKAP spectrum, indicating long-term brightening over 26 yr; the 3 GHz flux density rises by 2.3sigma between VLASS epochs 2.2 and 3.2. A
star-formation-only origin would require ~200 Msun/yr, against an unobscured H-alpha upper limit of 3.3 Msun/yr, implying an extreme obscured starburst. Ordinary
radio supernovae and tidal disruption events are strongly disfavoured by the luminosity and 30-yr recovery, while refractive scintillation would itself require an ultracompact nuclear emitter. The persistent
radio counterpart is best explained by
accretion onto the central black hole. Among the three
radio-detected local LRDs, this source is intermediate in luminosity and the only one with reported multi-year variability, adding a temporal dimension to the
radio diversity of the class.
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Accelerator Physics
A modern particle-in-cell code for beam-beam simulations of future colliders
Arianna Formenti, Remi Lehe, Axel Huebl et al. (+10 more)
A key challenge in the design of next-generation
colliders is predicting the effects of beam-beam interactions and using these predictions to optimize machine performance. Beam-beam interactions are characterized by strong focusing forces, radiative effects, and the generation of background particles. While analytical formulas provide insight into the dynamics of beam-beam interactions, these nonlinear, coupled effects are most accurately described with numerical methods. In this paper, we introduce the open-source particle-in-
cell code WarpX as a modern tool for modeling the interaction point in future lepton
colliders. WarpX provides high-performance execution on distributed GPU architectures within an open-source and actively maintained code base. We present convergence scans and
benchmarks against the established beam-beam codes GUINEA-PIG (v1.2.2) and CAIN (v2.42) for luminosity spectra,
photon emission, and secondary-particle production under a wide range of beam parameters corresponding to different
collider concepts. Our results show that WarpX (v26.09) reproduces the
benchmark beam-beam observables while enabling GPU-portable, extensible simulations. These results establish WarpX as a scalable platform for high-fidelity beam-beam modeling in future
collider studies.
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All authors Arianna Formenti, Remi Lehe, Axel Huebl, Stepan S. Bulanov, Jens Osterhoff, Andrew Myers, Weiqun Zhang, Spencer Gessner, Peter Kicsiny, Anna Kinderman, Bao Nguyen, Jinseo Park, Jean-Luc Vay
Astrophysics of Galaxies
Sulphur-bearing molecule survey towards prestellar and starless cores in the Perseus molecular cloud
J. Ferrer Asensio, S. Scibelli, A. Pokorny-Yadav et al. (+7 more)
Sulphur is drastically depleted from the gas phase in dense starless and prestellar cores, creating the long-standing "missing sulphur problem". Observations of sulphur-bearing molecules are crucial to understanding sulphur chemistry, core-environment relationships, and the physical
evolution of
star-forming regions. We present a survey of four sulphur-bearing molecules, HCS+, OCS, H2CS, and SO, towards 15 starless and prestellar cores in the Perseus molecular cloud using the Yebes 40m
telescope. The HCS+ 1-0, OCS 3-2 and 4-3, H2CS 1_{0,1}-0_{0,0}, and SO 3_2-2_2 transitions were observed, fitted with Gaussian profiles, and column densities were calculated assuming local thermodynamic
equilibrium (LTE). We also compare these with observations of CS, CCS, and CCCS from a previous study. HCS+, OCS, H2CS, and SO are detected in 100%, 93%, 100%, and 73% of the sample, respectively. Derived column densities are (2.2-17.0)x10^11 cm^-2 for HCS+, (1.9-25.0)x10^12 cm^-2 for OCS, (1.0-15.0)x10^12 cm^-2 for H2CS, and (0.3-17.0)x10^13 cm^-2 for SO, spanning over an order of magnitude. HCS+ and SO abundances strongly correlate (inversely and directly, respectively) with core volume density, reinforcing their early- and late-type status. Correlations indicate a differentiation between carbon and oxygen chemistry for sulphur-bearing molecules, with CS showing the strongest correlations as expected. Cores in protostellar outflow paths do not show consistently higher abundances. The chemical age (SO/CS) correlates with physical age (volume density), except for Per752, an outlier likely linked to an enhanced
cosmic ray ionization rate. These results provide a robust observational baseline constraining chemical models of sulphur chemistry in early
star formation.
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All authors J. Ferrer Asensio, S. Scibelli, A. Pokorny-Yadav, L. Steffes, B. Kulterer, Y. Shirley, A. Megías, I. Jiménez-Serra, A. Fuente, G. Esplugues
Physics and Society
Hurricane recovery gaps lie in reconnection, not local restart
Angelina Liu, Mengqiu Cao, Sen Pei et al. (+1 more)
Climate-intensified hurricanes disrupt urban mobility, yet whether recovery is equitable across the rural-urban gradient is unclear. Analyzing device-based mobility for Hurricanes Helene and Milton, we find local activity restarted within approximately 4.5 days in both storms, whereas reconnection to the outside world took 5 days in coastal-urban Florida but 11 in inland-rural Appalachia. The gap lies in external reconnection, not local restart, implying planners should target rural isolation.
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All authors Angelina Liu, Mengqiu Cao, Sen Pei, Qing Yao