Instrumentation and Methods for Astrophysics
CCAT: Design and Characterization of the 350 GHz Instrument Module
Ben Keller, Jordan Wheeler, Cody J. Duell et al. (+23 more)
The CCAT Collaboration's
Prime-Cam instrument will soon be deployed to the Fred Young Submillimeter
Telescope (FYST) in Chile's Atacama Desert. Featuring prominently in
Prime-Cam's calibration and early science observations will be the 350 GHz instrument module, a broadband camera that will field more than 10,000 microwave kinetic inductance detectors (KIDs) across three detector arrays. Forecasts show this module will be capable of making the most sensitive to-date measurements of polarized
dust emission over a large fraction of the sky at this frequency, enabling new
galactic polarization science and improved understanding of cosmological foregrounds. In this work we discuss the design of the 350 GHz instrument module, covering aspects of the optics, readout, and detector arrays. We then report on the results of in-lab testing of the fully-integrated module, achieving stable cryogenic performance with a 100 mK focal plane, high detector yield, and a passband comparable to designed specifications. Upon completion of these tests, this module was shipped to the
telescope site in Chile for integration in
Prime-Cam.
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All authors Ben Keller, Jordan Wheeler, Cody J. Duell, Darshan A. Patel, Jason Austermann, Baird D. Bankovic, James Burgoyne, Scott Chapman, Steve K. Choi, Rodrigo Freundt, Min Gao, Eliza Gazda, Anthony I. Huber, Johannes Hubmayr, Lawrence T. Lin, Quintin Meyers, Paul Malachuk, Alicia Middleton, Michael D. Niemack, Tilak M. Patel, Anna Vaskuri, Eve Vavagiakis, Michael R. Vissers, Samantha Walker, Yuhan Wang, Ruixuan Xie
General Relativity and Quantum Cosmology
Correlation-based Modeling of Seismic Newtonian Noise in Half-Space and Full-Space Media
Mohamed Samy, Jan Harms and Tomislav Andric
Seismic Newtonian noise, arising from fluctuating gravitational forces on detector test masses due to ambient seismic activity, represents a fundamental sensitivity limit for low-frequency gravitational-wave observatories such as the Einstein
Telescope. Effective mitigation of Newtonian noise requires detailed knowledge of the statistical correlations between the Newtonian acceleration perturbation at the test mass and the seismic displacement field measured by surrounding sensor arrays. In this work, the gravitoelastic correlation tensors (the cross-correlations between the Newtonian acceleration perturbation and the seismic displacement field) are derived and numerically validated for Rayleigh waves and body waves in half-space and full-space media, considering test masses located above and below ground, with and without a spherical cavity. The analytical solutions provide exact and asymptotic
benchmarks for validating a Cartesian numerical integration framework, which reproduces the corresponding gravitoelastic tensors across Rayleigh-wave and body-wave models, establishing a unified tool for Newtonian-noise modeling and sensor-array design in future gravitational-wave detectors.
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Materials Science
The crossmetric tensor and the geometrical meaning of the imaginary numbers
Cyril Cayron
The product of two Cartesian quaternions can be written as a quadratic form based on a 4x4
matrix made of the imaginary numbers i,j,k introduced by Hamilton. We generalized this
matrix to non-Cartesian bases, and showed that the
matrix is made of the metric and the cross tensors. We called it crossmetric tensor. Its symbols are ia,ib,ic; they are the elementary crystallographic quaternions. We determined the crossmetric tensors for the six
crystal families. We also showed that any unit crystallographic quaternion can be geometrically represented by an infinity of pairs of oriented planes intersecting along the vectorial component of the quaternion such that the angle between them is the semiangle of the rotation. The composition of quaternions follows the intuitive source-target rule. The elementary quaternions ia,ib,ic are geometrically represented by pair of perpendicular and oriented planes intersecting along the axis a,b,c, respectively. Three other complementary quaternions were also introduced. They are the pairs of planes ma, mb, mc. The elementary quaternions follow Hamilton rules on the squares of imaginary numbers. The complementary quaternions follow Hamilton rules on the bi and tri-products. For Cartesian basis, the quaternions i,j,k appear as a specific case of crystallographic quaternions. They are formed by the pairs of perpendicular faces of the cube mx, my, mz.
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Quantum Physics
Representational separation between unitary and channel quantum generative models via shared classical randomness at shallow depth
Arunava Majumder, Marius Krumm, Hendrik Poulsen Nautrup et al. (+1 more)
Near-term
quantum hardware limits
circuit depth and often imposes geometrically local connectivity for
quantum generative models, restricting the output distributions accessible to shallow
unitary Born models. Introducing stochasticity into a
unitary quantum Born model can improve the empirical generative performance of the resulting channel model and, for a restricted small-scale architecture, has been proven to represent a strictly larger family of distributions than its
unitary counterpart. However, whether such randomness provides a provable separation at fixed shallow depth for arbitrarily large systems has remained open. Here, we show that shared classical randomness, a comparatively weak resource from
entanglement theory, is sufficient to establish such a strict scalable representational separation over the corresponding shallow
unitary Born model. More specifically, we augment bounded-connectivity shallow
unitary circuits, followed by computational-basis measurements, with spatially separated local Pauli operations, whose joint application is controlled by a single classically sampled random bit. The resulting shallow-depth channel model generates long-range correlations in the classical output distribution that no purely
unitary shallow-depth model with bounded connectivity can reproduce. For one-dimensional nearest-neighbour architectures, reproducing such distributions with a purely
unitary model can require depth $\Omega(N)$ in the worst case. We further show that measurement-based
quantum computation (MBQC) provides a natural implementation of the required shared classical randomness through suitable adaptation of the random measurement outcomes. Numerical experiments on MBQC-based generative models support the analytical results.
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All authors Arunava Majumder, Marius Krumm, Hendrik Poulsen Nautrup, Hans J. Briegel
Optics · Cross-listed from eess.IV
AI-based single-shot structured-light depth reconstruction for real-time laparoscopic surgical guidance
Wayne Wonseok Rodgers, Xiangyi Le, Seonghoon Jang et al. (+5 more)
Significance. Accurate intraoperative depth perception is important for autonomous and semi-autonomous robotic laparoscopic surgery. Conventional fringe projection profilometry can achieve millimeter-scale accuracy but often requires multi-shot acquisition, digital-micromirror-device projection, and projector-camera synchronization, complicating integration into compact laparoscopic systems. Aim. To develop a synchronization-free, single-shot depth-sensing platform using a passive LED-illuminated binary mask and a VQ-VAE prior with a custom U-Net depth head. Approach. A compact projection module was coupled to one channel of a dual-channel laparoscope, while the second channel imaged the fringe-illuminated target. A Zivid 3D camera acquired reference depth for 722 paired phantom images. Zivid depth maps were reprojected into the SSLE image frame for supervised training and evaluation. The VQ-VAE encoded each input into a discrete latent representation, and a latent-space U-Net predicted depth without a separate mask-prediction branch. Results. Using a fixed train/validation/test split, the proposed model achieved an MAE of 3.70 mm, AbsRel of 0.0326, delta=1.1 accuracy of 0.962, and delta=1.1^2 accuracy of 0.970. It achieved lower MAE than the dual U-Net MaskNet + DepthNet baseline and outperformed off-the-shelf
monocular depth models in MAE, AbsRel, and threshold accuracy. The pipeline operated at 26.0 Hz over 301 consecutive frames on an NVIDIA A100 GPU. Conclusions. The LED-illuminated binary-pattern platform with latent-space depth reconstruction enables synchronization-free,
video-rate endoscopic depth estimation. Results demonstrate Zivid-referenced phantom reconstruction without an explicit
segmentation stage, while emphasizing the importance of
dataset size and SSLE-Zivid calibration accuracy.
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All authors Wayne Wonseok Rodgers, Xiangyi Le, Seonghoon Jang, Shuwen Wei, Justin Opfermann, Michael Kam, Axel Krieger, Jin U. Kang
High Energy Astrophysical Phenomena
Constraining Lorentz invariance violation from the depth of air-shower maximum
Nickolay S. Martynenko, Grigory I. Rubtsov, Petr S. Satunin et al. (+2 more)
Hypothetical Lorentz invariance violation (LIV) remains strongly constrained but has not been excluded as a possible manifestation of new high-energy physics. In subluminal
photon-sector LIV, suppressed Bethe$\unicode{x2013}$Heitler pair production modifies the electromagnetic component of extensive air showers. We present a simulation-based toy analysis of this effect using published Pierre Auger fluorescence-detector distributions of the reconstructed depth of air-shower maximum. The modified distributions of the depth of the shower maximum are folded with the Auger detector-response parametrizations and compared with the data using free composition fractions in each reconstructed-energy bin. Within this approach, the comparison gives a sensitivity to LIV compatible with that expected from ultra-high-energy
photon-induced showers. We obtain $M_{\rm LIV}>1.5\times 10^{21}\,\text{GeV}$ ($95\%$ confidence level). This result should not be interpreted as a detector-level experimental limit because the detector response and reconstruction are simplified, and the result remains composition dependent. However, the approach presented here opens the way for constraining LIV in hadronic air showers with more detailed analyses.
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All authors Nickolay S. Martynenko, Grigory I. Rubtsov, Petr S. Satunin, Andrey K. Sharofeev, Sergey V. Troitsky
Mathematical Physics · Cross-listed from math.PR
Cluster-Cluster model in $\mathbb{Z}^d$
Noam Berger, Eviatar B. Procaccia, Dominik Schmid et al. (+1 more)
We consider a
stochastic process on $\mathbb{Z}^d$ for $d \geq 1$. Given a translation invariant and ergodic starting configuration of finite clusters, each cluster $C$ performs a continuous time simple random walk with rate $|C|^{-\alpha}$. If it attempts to move to a vertex occupied by another cluster, it does not move, and instead the two clusters connect via a new edge. In all dimensions, we show that if $\alpha\ge 0$, there is almost surely no spontaneous creation of an infinite cluster within finite time. Moreover, for any $\alpha\le-1-2/d$ there is a finite-time blowup almost surely. In the regime $\alpha\in(-1,0)$ we show that the behavior greatly depends on the initial configuration. In addition, in dimension one, we establish the exact phase diagram.
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All authors Noam Berger, Eviatar B. Procaccia, Dominik Schmid, Daniel Sharon
Mathematical Physics · Cross-listed from cs.LG
Multimodal Spatiotemporal Atmospheric Data Assimilation with Latent Video Flow-matching
Dibyajyoti Chakraborty and Romit Maulik
Data assimilation (DA) uses
Bayesian inference to update the state of a numerical forecast model with observed data. In this study, we propose a fundamentally different, unified approach to atmospheric data assimilation. We use latent
video flow-matching to sample temporally consistent trajectories from a prior trained using ERA5 reanalysis (69 variables over an 8-day window). We also use posterior sampling to assimilate real observation sources, such as those from the NOAA Integrated Global Radiosonde Archive and the Integrated Surface Database. Because the prior generates a continuous trajectory, it naturally propagates information between observed and unobserved frames. Therefore, we can perform various DA tasks, such as filtering and smoothing, simply by changing the observed frames. Moreover, we generate full-state ensemble forecasts directly from sparse observations, achieving performance competitive with state-of-the-art observation-to-forecast models.
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Lattice Field Theory
From One to Eight: Supersymmetry Restoration in Lattice 3D ${\cal N} = 4$ Super Yang–Mills
Dario van den Berg and Anosh Joseph
Topological twisting provides a powerful framework for constructing
lattice formulations of supersymmetric gauge theories. In three dimensions, a twisted version of ${\cal N} = 4$ super Yang–Mills theory can be discretized so that one nilpotent scalar supersymmetry is preserved exactly at nonzero
lattice spacing. The remaining seven supersymmetries are broken by
lattice artifacts of ${\cal O}(a)$, where $a$ is the
lattice spacing. An important question is whether these supersymmetries are automatically restored in the continuum limit $a \to 0$, or whether fine-tuning of the
lattice couplings is required. In this work, we derive the additional twisted supersymmetries by combining discrete $R$-
symmetries of the continuum theory with the action of the scalar supercharge. This construction suggests that restoration of rotational
symmetry in the continuum limit implies restoration of $R$-
symmetry, leading to an automatic enhancement to the full ${\cal N} = 4$ supersymmetry without further tuning. These results may enable nonperturbative
lattice studies of three-dimensional supersymmetric gauge theories relevant to string theory and mirror
symmetry.
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High Energy Astrophysical Phenomena
Dissecting the Nuclear Structure of NGC 5548 with XRISM. I. Physical Properties of the Highly Ionized Outflows
Missagh Mehdipour, Jon M. Miller, Jelle S. Kaastra et al. (+21 more)
We present a detailed spectral analysis of an X-Ray Imaging and Spectroscopy Mission (XRISM) observation of the prototypical Seyfert 1
galaxy NGC 5548. XRISM's Resolve microcalorimeter reveals, for the first time, highly ionized
outflows in this active
galactic nucleus (AGN) through the detection of Fe XXV and Fe XXVI absorption lines in the Fe K band. Modeling the XRISM/Resolve spectrum alongside XMM-Newton Reflection Grating Spectrometer (RGS) data allows us to probe the ionization and kinematic structure of the
outflows in this AGN. We identify four distinct ionization components, with ionization parameters log $\xi$ ranging from 0.9 to 3.4. Three of these components are further resolved into two velocity sub-components, demonstrating the multiphase structure of the
outflows. The measured
outflow velocities span 240 to 2730 km/s. We find a trend of increasing column density with ionization parameter ($\xi$), along with a general pattern of increasing
outflow velocity with $\xi$. The XRISM/Resolve spectrum provides a far more detailed absorption measure distribution (AMD) than was previously possible, revealing two distinct slopes above and below $\log\xi \sim 2.6$. A comparison of the Fe XXV absorption line profile with UV absorption lines (C IV and Ly$\alpha$) observed with the Hubble Space
Telescope reveals both overlaps and deviations. The XRISM/Resolve results suggest a multiphase, clumpy
outflow in NGC 5548, consistent with a "hybrid wind" scenario in which the observed parameter trends arise from multiple origins and driving mechanisms.
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All authors Missagh Mehdipour, Jon M. Miller, Jelle S. Kaastra, Gerard A. Kriss, Keigo Fukumura, Liyi Gu, Doyee Byun, Xin Xiang, Ehud Behar, Laura W. Brenneman, Elisa Costantini, Maryam Dehghanian, Jacobo Ebrero, Massimo Gaspari, Anna Juráňová, Erin Kara, Chen Li, Junjie Mao, Hirofumi Noda, Anna Ogorzalek, Ioanna Psaradaki, Daniele Rogantini, Sascha T. Zeegers, Keqin Zhao
High Energy Physics (Phenomenology)
High energy probes of Higgs self-coupling via $W$ boson fusion at future lepton colliders
Amir Subba, Hrishikesh Deka, Subhaditya Bhattacharya et al. (+1 more)
We investigate the sensitivity to the
Higgs self-coupling through $W$
boson fusion di-
Higgs production at CLIC with a center-of-mass energy of $\sqrt{s}=3$~TeV. We study the interplay between the
Higgs self-coupling modifier ($\kappa_{\lambda}$) and
Higgs-gauge
boson coupling modifiers ($\kappa_{V}$ and $\kappa_{2V}$) within the $\kappa$ framework. To enhance the separation between signal and background, we develop a graph neural network (GNN) based classifier that achieves a signal significance of $\mathscr{Z}\approx 20~\sigma$ at $5~\mathrm{ab}^{-1}$, substantially exceeding projected HL-LHC sensitivity. Our results demonstrate that high-energy
lepton colliders, combined with graph-based machine learning, provide excellent sensitivity to the
Higgs self-coupling and offer a powerful probe of new physics in the electroweak sector, potentially disentangling underlying SMEFT-like and HEFT-like structures.
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All authors Amir Subba, Hrishikesh Deka, Subhaditya Bhattacharya, Abhik Sarkar
Accelerator Physics
Building a Start-to-End Model of the CESR Injector Linac
Ryland Goldman, Adam Bartnik and Jared Maxson
The CESR injector linac supplies positrons to the Cornell Electron Storage Ring in six stages: a thermionic cathode, a 150 kV DC gun, a prebuncher, four electron linac sections, a tungsten positron converter, and four positron linacs. We present a start-to-end model of the full chain, built in Python from open-source codes. WarpX is used for the space-charge-dominated cathode, gun, prebuncher, and electron linacs, Geant4 for positron production, and Impact-T for the positron linacs. The beam reaches the converter at 146 MeV and the recaptured positrons are accelerated to 250 MeV. Stage configurations are written in YAML to allow algorithmic adjustment by Xopt for ML optimization.
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Quantum Physics
Imaginarity as a necessary resource for trainability in QAOA
Syed Muhammad Ali Hassan, Kostas Blekos, Stefan Kühn et al. (+2 more)
The
quantum approximate optimization
algorithm (QAOA) tackles combinatorial problems by tuning a
quantum circuit in a classical loop, often guided by gradients. We show that the gradient used to tune the
circuit's final parameter is bounded by imaginarity, which weights phase relationships between candidate solutions by how strongly the
circuit connects them and how differently the problem scores them. Imaginarity is necessary but not sufficient for a nonzero gradient. We extend the bound to three common noise models and compare it numerically with the gradient in Max-Cut simulations.
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All authors Syed Muhammad Ali Hassan, Kostas Blekos, Stefan Kühn, Nikos Kollas, Karl Jansen
Quantum Physics
Perfect Games in Dimension-Bounded Communication
Emmanuel Zambrini Cruzeiro
Perfect prepare-and-measure games exhibit an all-or-nothing
quantum advantage: a
quantum system of dimension $d$ satisfies every prescribed winning constraint, whereas a classical $d$-level message cannot. We establish three structural results for such forbidden-output support constraints. First, every binary-output support game reduces exactly to a conflict graph: perfect classical realization with a $d$-level message is equivalent to $d$-colorability, perfect $d$-dimensional
quantum realization is equivalent to a $d$-dimensional orthogonal representation, and the minimum number of Bob inputs realizing a fixed conflict graph is its edge biclique-cover number. Second, for an arbitrary finite output alphabet, every perfect
qubit strategy admits a perfect classical-bit realization. Third, with at most two Bob inputs every perfect qutrit strategy admits a perfect classical-trit realization. An explicit seven-preparation qutrit game with three Bob inputs satisfies $C_3=20<Q_3=S=21$, so three Bob inputs are necessary and sufficient in dimension three. Conversely, a two-input, six-output game in dimension five satisfies $C_5=39<Q_5=S=40$. Thus the smallest dimension admitting a two-input perfect same-dimensional separation is either four or five; the four-dimensional case remains open. As a flagship binary application, the $13$-ray qutrit graph yields a compressed game $(X,Y,B)=(13,8,2)$ with $C_3=39<Q_3=S=40$, and eight Bob inputs are minimal among all binary-output realizations of that graph. Graph extensions demonstrate the mechanism in every dimension, while Torpedo and antidistinguishability games illustrate the genuinely nonbinary regime. These results connect exact communication, graph coloring, contextuality, state exclusion, and zero-error information theory.
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Solar and Stellar Astrophysics
Spherically Polarized Alfvén Waves and the Gosling Boost
Yuliang Ding, Marco Velli, Zesen Huang et al. (+6 more)
Alfvén waves are thought to play critical roles in
solar wind acceleration and
plasma heating in the
solar corona and inner heliosphere. Parker
Solar Probe (PSP) has highlighted the role of large amplitude Spherically Polarized Alfvén Waves (SPAWs), where the locally constant
magnetic field magnitude $|\mathbf{B}|$ together with outward propagation explains the observed one sided radial velocity enhancement - the Gosling boost. Starting from the MHD equations, we derive the modified wave pressure and Poynting flux under the SPAW condition, and demonstrate both are governed solely by the transverse
magnetic fluctuations. Using PSP data from Encounters 6–25, we define an unperturbed velocity baseline from the lower 10th-percentile running average and statistically characterize the radial
evolution of Alfvénic fluctuations. The background
solar wind velocity shows clear radial acceleration, while the velocity perturbation amplitude $\delta v$ decreases with heliocentric distance. This decay is anisotropic between the radial and perpendicular directions, which is a direct consequence of the growing
magnetic deflection angle related to the spherical polarization. Our results demonstrate that radial velocity enhancements in the young
solar wind arise naturally from SPAWs rather than from localized velocity jets, and provide direct observational evidence for the anisotropic radial
evolution of SPAWs in the inner heliosphere.
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All authors Yuliang Ding, Marco Velli, Zesen Huang, Chen Shi, Lorenzo Matteini, Nikos Sioulas, Stuart D. Bale, Anna Tenerani, Mingzhe Liu
Mathematical Physics · Cross-listed from math.PR
Correlation decay in area-tilted line ensembles
Shirshendu Ganguly and Vilas Winstein
Random surfaces on a hard substrate often exhibit entropic repulsion, wherein the surface is propelled upwards to allow entropically preferable downward fluctuations. A particularly rich class of examples arises from the low-temperature 3D Ising model. A powerful approach to studying such surfaces is through their level curves, which form a family of non-intersecting random curves. In [CIW18, CIW19], an ensemble of Brownian lines with geometrically increasing area tilts was proposed as a putative limiting model in this case. This model falls outside the scope of techniques based on integrable or SDE structures, which have been key ingredients in the study of the Airy line ensemble. A particularly intriguing question about such line ensembles concerns their mixing properties when viewed as a Markov process, and in particular the rate of decay of correlations in time. For the Airy line ensemble, this decay is known to be inverse quadratic. The first quantitative bound on the decay of correlations in the area-tilted model, established in [CG25], was slower than
polynomial in time. An earlier result [DLZ24] had established positivity of the spectral gap for the finite-line version of the ensemble, without quantitative bounds. This left open the important question of the true decay rate of correlations for the infinite ensemble. Settling this question for sufficiently large area-tilt strength, corresponding to sufficiently low temperature for the 3D Ising model, we prove exponential decay of correlations for the infinite ensemble and a uniform (in the number of lines) positive spectral gap for the finite ensemble. Our proof is based on establishing a precise form of separation of scales between curves of different indices, using a novel probabilistic approach involving
embedding supercritical branching processes in the line ensemble.
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Soft Condensed Matter
It Takes Two to Tribo: Stochastic Charge Evolution in Repeated Binary Collisions of Acoustically Levitated Particles
Tom F. O'Hara, Adrian C. Barnes, Nathan Croll Dawes et al. (+1 more)
The mechanisms governing triboelectric charging between insulating particles of the same material remain an open question in nonequilibrium physics, with several competing models proposed to explain observed charging behaviour. Here, we investigate charge
evolution in a minimal system consisting of two acoustically levitated particles undergoing repeated binary collisions. To quantify particle charge transfer, purpose-built Faraday cage picoammeters were developed and calibrated. The MultiLev acoustic levitation system was used alongside Ultraino simulations to generate transducer control signals, enabling controlled collision and separation of polystyrene (PS) particles. Although individual collision events exhibit
stochastic charge transfer, described by skew-normal distributions, we demonstrate for the first time that the cumulative charge
evolution of an individual acoustically levitated particle pair follows the saturation behaviour predicted by the condenser model of triboelectric charging, with fits achieving $R^2 > 0.99$. Under identical conditions, conductive graphite-coated PS particles also undergo charge transfer, but accumulate substantially less charge, consistent with the distinct charging behaviour expected for conductive materials.
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All authors Tom F. O'Hara, Adrian C. Barnes, Nathan Croll Dawes, Karen L. Aplin
High Energy Physics (Phenomenology)
Generalized Glauber theorem for dark-matter axion and graviton detection
Jakub Bręczewski, Ayuki Kamada and Akira Miyazaki
We revisit the generalized Glauber
theorem motivated by recent applications to dark-matter
axion searches and graviton production. For
Hamiltonian containing up to quadratic terms in annihilation and creation operators coupled to classical sources, the time-
evolution operator can be factorized into displacement, squeezing, and rotation operators. We derive the differential equations governing time
evolution of their parameters, reducing the
quantum dynamics to c-number equations that can be solved analytically or numerically. To compare another form of the time-
evolution operator, Dyson series, we demonstrate the essential role of time ordering. This formalism based on generalized Glauber
theorem provides a unified description of particle production from classical backgrounds.
Axion-
photon conversion in microwave haloscopes is recovered as the linear-interaction limit, while squeezed graviton production from black-hole mergers follows naturally from quadratic interactions. Extending the
theorem to thermal initial states yields a realistic
quantum description of microwave cavities used in
axion experiments. We show that higher-order
photon statistics exhibit nontrivial behavior, providing a rigorous foundation for Monte Carlo simulations of
quantum-enhanced
axion searches beyond heuristic noise estimates.
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General Relativity and Quantum Cosmology
Post-Inflationary Constraints on Nonminimally Coupled Quintessential Inflation
Min Gi Park, Seong Chan Park, Tomo Takahashi et al. (+1 more)
We investigate quintessential inflation in a nonminimally coupled scalar-tensor theory, parameterizing the post-inflationary radiation abundance independently of the reheating mechanism. The nonadiabatic inflation-kination transition generates a
stochastic gravitational-wave background whose contribution to $\Delta N_{\textrm{eff}}$ imposes a lower limit on the reheating temperature. Because this temperature dictates the duration of kination and the available scalar-field excursion, it directly constrains the present-day dark-energy equation of state. While a single-exponential coupling achieves the required post-inflationary potential drop, the same constant slope does not provide viable late-time acceleration. A double-exponential deformation resolves this tension by decoupling the average slope governing the total potential drop from the asymptotic slope driving
cosmic acceleration. Full numerical solutions confirm this picture, yielding a thawing quintessence regime with $w_{\varphi,0}\simeq (-0.90, -0.95)$ for our
benchmarks. Our results demonstrate that future dark-energy measurements can directly probe the post-inflationary reheating history of the Universe.
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All authors Min Gi Park, Seong Chan Park, Tomo Takahashi, José Jaime Terente Díaz
Optics
Mask-free fast patterning of organic light-emitting diode pixels using laser-assisted close-space sublimation
Subhamoy Sahoo, Jain Jose, Mani R et al. (+8 more)
Existing patterning processes for organic light-emitting diode displays offer micrometer-scale precision but are constrained by long processing times for large-area substrates. In this work, we study a fast growth method for patterned organic film deposition, aimed at applications including active-
matrix organic light-emitting diode displays. The approach employs a specially engineered donor substrate in a close-space sublimation configuration combined with
laser heating. The donor substrate incorporates spatially patterned absorber and reflector layers that enable selective, one-step or two-step transfer of organic material onto a receiver substrate. We analyze the optical response and heat-transfer dynamics that govern the selective transfer mechanism and demonstrate precise pixel patterning with micrometer-scale spatial fidelity. The reliability and practical applicability of the method are validated by fabricating light-emitting diode devices by using this rapid transfer process and benchmarking their performance against devices produced via conventional
vacuum thermal evaporation. The resulting devices exhibit comparable optoelectronic performance, confirming the robustness and technological relevance of the proposed strategy for scalable fabrication of patterned organic light-emitting diodes for display application.
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All authors Subhamoy Sahoo, Jain Jose, Mani R, Arghya Saha, Kanimozhi V, Dhruvajyoti Barah, R. Bairava Ganesh, Amitava Majumdar, Jayeeta Bhattacharyya, G Rajeswaran, Debdutta Ray
Instrumentation and Methods for Astrophysics
CCAT: Characterization of the first science-grade MKID array for the Prime-Cam 850 GHz module
Anthony I. Huber, Jordan Wheeler, James Burgoyne et al. (+15 more)
The Fred Young Submillimeter
Telescope (FYST) is a 6-meter crossed-Dragone
telescope developed by the CCAT collaboration. Sited at 5600 m on Cerro Chajnantor in the Atacama Plateau of Chile, FYST aims to provide superior atmospheric transmission and a wide field of view for submillimeter observations.
Prime-Cam is a first-generation instrument for FYST designed to house up to seven separate instrument modules. Among these, the 850 GHz module represents the highest-frequency band and is optimized for ultra-sensitive broadband polarimetry and imaging. This module is designed to deploy ~38,000 polarization-sensitive lumped-element titanium-nitride (TiN) microwave kinetic inductance detectors (MKIDs) across three arrays. Thus the 850 GHz module will have the most submillimeter MKIDs in a single instrument module to date. These detectors have adopted a novel two-octave design to maximize the multiplexing achieved using a RFSoC readout system. We review the design parameters and fabrication process for the first 850 GHz science-grade array. The preliminary measurements of the array show a fabrication yield of 99%, highlighting the successful application of the design and fabrication process. We further present the cryogenic characterization of the first full MKID array developed for the
Prime-Cam 850 GHz module. Multiple tests were performed on the devices including resonator frequency mapping, quality factor measurements, optical load sweeps and noise performance. From these measurements, we discuss the measured optical efficiency, sensitivity, and uniformity across the array and the expected on-sky performance of the module. The 850 GHz module will be deployed for observing in 2027.
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All authors Anthony I. Huber, Jordan Wheeler, James Burgoyne, Scott Chapman, Jason Austermann, James Beall, Steve K. Choi, Doug Henke, Johannes Hubmayr, Ben Keller, Matthew Koc, Jeff van Lanen, Tilak Patel, Adrian Sinclair, Anna Vaskuri, Eve M. Vavagiakis, Michael Vissers, Ruixuan Xie
High Energy Physics (Theory)
Generalized comodule tube algebras for boundary and domain wall defects of (2+1)D topological order
Zhian Jia and Sheng Tan
The tube
algebra, which carries the structure of a $C^*$ weak
Hopf algebra, is a fundamental tool for characterizing topological excitations in topological phases. In this work, we generalize the tube
algebra framework to codimension-2 defects in $(2+1)$D gapped phases described by Turaev–Viro–Barrett–Westbury TQFTs, with particular emphasis on Levin–Wen string-net models. We show that such codimension-2 defects are described by a defect tube
algebra, which naturally carries the structure of a comodule
algebra over the weak
Hopf tube
algebra associated with the topological excitations. Boundary and domain wall defects are then characterized by the representations of the corresponding boundary and domain wall defect tube
algebras. In particular, a domain wall defect tube
algebra can be regarded as a generalized Drinfeld double of the tube
algebras associated with the two adjacent boundary defects. More generally, for a domain wall joining $N$ bulk phases, the associated domain wall defect tube
algebra can be viewed as an $N$-tuple
algebra. This perspective extends naturally to general $k$-defects, namely codimension-2 defects joining $k$ codimension-1 defects, for which the resulting generalized tube
algebra carries the structure of a multicomodule
algebra.
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Materials Science
Effective single particle picture for anharmonic lattice dynamics: a Rosetta stone for electronic and ionic response
Giovanni Caldarelli and Francesco Mauri
We establish a theoretical framework for the dynamics of a
lattice of ions in a mean-field approach, where anharmonicity is included via self-consistency. In this picture, the many-body dynamics of a system of $N$ atoms in three dimensions is mapped onto two kinds of $6N$-dimensional vectors: the
phonon condensate, describing the
evolution of the average atomic positions, and the
phonon spinors, describing the
evolution of the atomic elastic constants. The
phonon spinors are classified by a
quantum number that behaves as a
spin: the
phonon pseudospin. The many-body Liouville equation is replaced by two wave equations equivalent to the time-dependent Schrödinger equation for the electronic wave function in density functional theory. Exploiting this parallelism, we formulate the response of the anharmonic
lattice in one-to-one correspondence with time-dependent density functional theory for electrons. In complete analogy with the electronic case, we express the ionic response in terms of
matrix elements of operators representing external fields and forces. We show how anharmonicity screens external perturbations through a
phonon analogue of the Hartree-exchange-correlation kernel. We provide expressions for the
lattice optical and thermal conductivity, showing how thermal conductivity depends on the
phonon pseudospin. By approximating the density
matrix as a Gaussian, we recover the equations of the time-dependent self-consistent harmonic approximation. In this case, the linear-response equations are formulated in terms of an anharmonic kernel including three- and four-
phonon scattering. By translating anharmonic
lattice dynamics into the
language of density functional theory, this work shows how theoretical and computational advances in modeling the dynamical response of interacting electrons can be directly applied to interacting ions.
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Atomic Physics
Diatomic molecular anions of alkali-metal and alkaline-earth-metal atoms
Sana Akkari, Hela Ladjimi, Wissem Zrafi et al. (+3 more)
Studies of anions are inherently more challenging than investigations of neutrals and cations because of the diffuse and weakly bound character of an anionic electron. Here, we present a comprehensive computational examination of ground-state diatomic molecular anions composed of alkali-metal (Li, Na, K, Rb, Cs, Fr) and alkaline-earth-metal (Be, Mg, Ca, Sr, Ba, Ra) atoms. We study 21 alkali-metal diatomic anions in the X$^{2}\Sigma^{+}$ electronic state and 36 alkali-metal–alkaline-earth-metal diatomic anions in the X$^{1}\Sigma^{+}$ electronic state. The calculations employ a hierarchy of the coupled cluster methods, combined with large Gaussian basis sets and small-core relativistic energy-consistent pseudopotentials for heavier elements. We compute potential energy curves, permanent electric dipole moments, and static polarizabilities, and we assess convergence and uncertainties of our results. Additionally, using the multireference configuration interaction and equation-of-motion electron-attachment coupled cluster methods, we investigate excited electronic states of alkali-metal molecular anions, including valence-bound and dipole-bound states. We predict crossings between ground neutral and excited anionic states, which may enhance resonant electron attachment and subsequent anion dissociation. This finding may be relevant for experiments with mixtures of ultracold ground-state alkali-metal molecules and Rydberg atoms.
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All authors Sana Akkari, Hela Ladjimi, Wissem Zrafi, Hamid Berriche, Marcin Gronowski, Michał Tomza
General Relativity and Quantum Cosmology
Multipolar static tidal response of Schwarzschild black holes in cubic gravity: a metric-action derivation of tidal running
Edilberto O. Silva
Static
tidal Love numbers of four-dimensional Schwarzschild black holes vanish in general relativity, whereas higher-
curvature interactions can generate a nontrivial response. We investigate the parity-even cubic Weyl correction directly in metric variables and derive the electric, static response for every integer multipole $\ell \geq 2$. Organizing the angular reduction through $L=\ell(\ell+1)$, we obtain exact radial actions and show that perturbative order reduction converts the three metric equations into a constrained two-dimensional first-order system. Eliminating one field yields a scalar equation whose homogeneous operator is precisely the general-relativistic static
tidal operator. A Frobenius and Green-function analysis gives the gauge-invariant Zerilli–Moncrief running coefficient $\beta_{\ell}^{\rm ZM}=\epsilon_{\rm e}\,7L^{2}(L-2)^{2}(L-4)(L-6)/12$ and identifies the factor $L-6$ as the reason why the quadrupole is the unique physical electric multipole without logarithmic running. We solve the quadrupole exactly, obtaining the fixed-integer branch ratio $-2400\,\epsilon_{\rm e}$ and explaining why it differs from the analytically continued canonical Love number $k_{2}^{E}=448\,\epsilon_{\rm e}$. For the octupole, we construct the complete horizon-regular global metric solution and exhibit the cancellation of horizon logarithms between the two Green-function channels. Finally, we derive the normalization map to the canonical electric beta functions and the corresponding running of finite-size worldline coefficients. The canonical result agrees with the modified-Teukolsky calculation, while the metric-action approach reveals the radial mechanism behind the exceptional quadrupole and provides the full metric reconstruction.
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Strongly Correlated Electrons
Direct Evidence for Robust Bulk Band Gap Across the Charge Density Wave Transition in TiSe2
Turgut Yilmaz, Anil Rajapitamahuni, Muhammad Awais Fiaz et al. (+7 more)
The mechanism driving the charge density wave (CDW) transition in TiSe2 has been debated for decades, with proposals ranging from an excitonic
insulator to a
lattice-driven instability. A central question remains whether the transition involves an opening or enhancement of the bulk band gap. Using high-resolution angle-resolved photoemission spectroscopy, we directly track the temperature
evolution of the bulk band edges across the CDW transition at TCDW = 200 K. Contrary to the expectation of a gap-opening transition, we find that the size of the fundamental band gap remains constant from the high-temperature normal phase down to 160 K. While the CDW induces clear band-folding signatures and spectral weight redistribution, the underlying band extrema are unperturbed. These results demonstrate that TiSe2 does not undergo a temperature-driven electronic gap opening. Instead, they support a scenario where the transition is governed by a
lattice symmetry-breaking reconstruction that folds, but does not gap, the electronic structure of a pre-existing band
insulator.
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All authors Turgut Yilmaz, Anil Rajapitamahuni, Muhammad Awais Fiaz, Zhenxian Liu, Jerzy T. Sadowski, Abdullah Al-Mahboob, Asish K. Kundu, Shawna M. Hollen, Boris Sinkovic, Elio Vescovo
Materials Science
HPHT growth of centimeter-sized cubic boron nitride crystals
Andrey Katrusha, Weihua Peng, Jianguo Peng et al. (+1 more)
Single
crystals of cubic boron nitride (cBN) exceeding 10 mm in size were grown by the high-pressure high-temperature (HPHT) temperature-gradient method using a Ni-Cr-based solvent catalyst. Compared with the previously reported maximum
crystal size of approximately 3 mm, this improvement was achieved by maintaining a stable precursor flux during one week of growth at a source temperature of 1950 {\deg}C. In contrast to diamonds, which were grown with the same HPHT
cell and showed nearly isometric shapes, the cBN
crystals had elongated shapes. We attribute this cBN morphology to a localized growth near the BN source due to the relatively low effective diffusivity of boron and nitrogen species in the metallic solvent.
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All authors Andrey Katrusha, Weihua Peng, Jianguo Peng, Konstantin Iakoubovskii
Earth and Planetary Astrophysics
MarsCast: Transfer Learning of AI Weather Foundation Models to Planetary Atmospheres
M.L. Carroll, J. Li, S.D. Guzewich et al. (+3 more)
We investigate the transferability of Earth weather foundation models to planetary atmospheres by adapting the GraphCast graph neural weather
forecasting model to Mars. While GraphCast achieves state-of-the-art performance for terrestrial
forecasting, its applicability to non-Earth environments remains unexplored. Using the Mars
Climate Database (MCD), which provides global atmospheric fields across vertical altitude levels (similar to Earth pressure levels), we evaluate zero-shot and fine-tuned GraphCast predictions of Martian temperature and wind fields. Zero-shot forecasts produce a surprisingly accurate depiction of current conditions but fail to reproduce diurnal variability and rapidly decay toward climatological mean states. To address this limitation, we fine-tune GraphCast using MCD variables and top-of-atmosphere
solar radiation forcing while holding humidity constant. Fine-tuning enables rapid learning of Martian thermal variability. Within as few as 10 training epochs, the model begins to capture the diurnal cycle and forecasts up to 10 days reproduce seasonal and vertical temperature structure. Prediction quality improves with training sample size and exhibits sensitivity to seasonal initialization. These results demonstrate that Earth-trained AI weather models can be adapted to simulate Martian atmospheric dynamics, providing a pathway toward rapid planetary weather prediction to support mission operations,
dust storm risk mitigation, and future human exploration.
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All authors M.L. Carroll, J. Li, S.D. Guzewich, G.Villanueva, J.A. Caraballo-Vega, M.J. Frost
Quantum Physics
Constructing Non-Hermitian Theories with Tunable Exceptional Points and Controlled State Purification
Soumya Kanti Pal, Rupak Majumder and Shamik Gupta
Exceptional points (EP's) are a hallmark of non-Hermitian
quantum systems. We show that momentum-space deformation provides a general design principle for creating and controlling EP's in quadratic many-body
Hamiltonians. We identify universal criteria for the momentum sectors to host EP's and the corresponding critical deformation strengths, while revealing that a single momentum-sector EP induces quite remarkably an exponential proliferation of many-body eigenvector coalescences. We further establish EP's as a universal mechanism for purifying arbitrary mixed
quantum states, uncovering distinct purification regimes and a fundamental odd-even system-size dichotomy in the thermodynamic limit. Our framework also provides a systematic reverse-engineering protocol for generating short- and long-range, reciprocal and nonreciprocal non-Hermitian
quantum matter, together with an explicit Lindblad
embedding. These results thus establish momentum-space deformation as a unified route to exceptional-point engineering and controlled design of many-body non-Hermitian
quantum systems.
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Materials Science
X-ray Thermal diffuse scattering from real-space displacement correlations
Benjamin Fahl, Jonathan Bulled, Artem Korshunov et al. (+3 more)
We introduce a method for calculating X-ray thermal diffuse scattering based on the three-dimensional difference pair distribution function (3D-dPDF). Within the harmonic approximation the method is exact, as it includes all orders of multi-
phonon scattering. A single
Fourier transform delivers the diffuse intensity over large volumes of reciprocal space. We tested the method against experimental diffuse scattering measured on a silicon single
crystal. With nothing refined beyond a scale and a background, the calculation reproduces the measured intensity to an R2 residual below 5%. Because the method uses the same pair-correlation
language as the established Yell program, thermal and static correlated disorder enter the analysis on equal footing.
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All authors Benjamin Fahl, Jonathan Bulled, Artem Korshunov, Dmitry Chernyshov, Yevheniia Kholina, Arkadiy Simonov