Quantum Physics
Ordered-Angle Coding for Exact Multiuser Unanimity Testing
Luis Adrián Lizama-Pérez
We introduce ordered-angle coding for binary-unanimity testing among $n$ transformation-only users in a serial
quantum architecture inherited from Loop-Back communication. User $B_i$ fixes one private sign across a logical word and applies $R(s_i\alpha_j)$ in trial $j$. If $w$ users choose the negative sign, serial composition gives $R[(n-2w)\alpha_j]$. We show that every fixed same-axis pulse that is deterministic for both unanimous inputs under the binary Bell readout has $\alpha_j=q_j\pi/(2n)$ with integer $q_j$. For a nonadaptive word $\mathbf q=(q_1,\ldots,q_m)$, a mixed Hamming weight imitates the unanimous signature with probability \[ M_{\mathbf q}(w)=\prod_{j=1}^{m}\cos^2\!\left(\frac{\pi q_jw}{n}\right). \] Within this complete deterministic-unanimity pulse family, a finite perfect word exists if and only if $n$ is a power of two. For $n=2^r$, the dyadic word $(1,2,4,\ldots,2^{r-1})$ is exact and pulse-minimal with $m_{\min}=r=\log_2n$ trials. It replaces the $O(n^2\log(1/\varepsilon))$ worst-case burden of repeated smallest-angle tests by exact $O(\log n)$ verification. Odd
primes instead admit balanced statistical words with uniform mixed-weight imitation $2^{-(p-1)}$. For actual operations $R(s_i\alpha_j+\delta_{ij})$, an ideal rejecting position is lifted to $\sin^2\Delta_j$, where $\Delta_j=\sum_i\delta_{ij}$. This yields explicit robustness bounds with angular and binary-readout errors. Bell
entanglement is not required for the additive
algebra, but it keeps the traveler locally maximally mixed in every honest trial. We therefore present the result as a coded multiuser relation primitive with optional raw conference-key-candidate use, not as a composably secure conference-key protocol.
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Quantum Physics
$N$-dimensional discrete Fourier transform via bosonic Hamiltonian
Edgar Barriga, Camila Muñoz, Alejandro Muñoz et al. (+4 more)
The discrete
Fourier transform (DFT) underpins many classical
algorithms and is a fundamental
unitary operator for
quantum information processing. Implementing the $N$-dimensional DFT in photonic integrated
circuits (PICs) is limited by the cascades of Mach-Zehnder interferometers that current architectures require. Here we propose bosonic
Hamiltonians that realize the $N$-dimensional DFT through a single stage of multimode
evolution, complemented only by phase shifters before and after the interaction region, in a geometry suited to 3D waveguides. Modeling the system as a graph, where edges correspond to couplings and the vertices are the waveguides, we obtain analytical solutions for complete graphs up to $N=6$ and numerical solutions up to $N=31$. For non-complete graphs, different propagation constants are required in the
Hamiltonian. We report all solutions for $N\leq 8$, partial exploration for $N=9$, and selected cases for $N=10$, together with three
conjectures that guide the numerical search for $N \geq 11$. These configurations circumvent the vanishing evanescent coupling strength imposed by the waveguide separation, and a closed-form sensitivity criterion selects those that are admissible as a waveguide layout and least sensitive to fabrication error. We also uncover the missing non-affine parameters of the $6$-dimensional DFT, and show that the scaling law for implementing the $N$-dimensional DFT with our building blocks is $\mathcal{O}(N\log\log{N})$. This allows assembling the $2520$-dimensional DFT with only $2625$ interferometers, in contrast to the $\approx 3\times 10^6$ of Reck and Clements architectures.
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All authors Edgar Barriga, Camila Muñoz, Alejandro Muñoz, Santiago Rojas-Rojas, Pablo Solano, Carla Hermann-Avigliano, Aldo Delgado
Materials Science · Cross-listed from cs.AI
The convergent laboratory: when AI reasoning, autonomous experiments, high performance and quantum computing reshape chemistry
Eliu Huerta, Xiaoyun Wang, Geetika Gupta et al. (+7 more)
This Comment emerges from TPC26 (https://tpc26.org), a conference convening leaders from academia, national laboratories, and industry who are reshaping materials science discovery. The meeting explored how AI, autonomous
agents, self-driving labs, higher performance and
quantum computing converge to amplify their individual impact on materials science discovery. The perspectives here reflect the firsthand experiences of researchers at these frontiers and capture the essence of this global endeavor. As AI-driven
reasoning, autonomous agentic frameworks, self-driving laboratories, and fault-tolerant
quantum processors mature simultaneously, we offer this Comment as a reference at what we believe is a tipping point of transformative advances and productive disruption in the chemical sciences.
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All authors Eliu Huerta, Xiaoyun Wang, Geetika Gupta, Edward H. Sargent, Cameron J. Owen, Victor Fung, Abhishek Mitra, Austin Cheng, Emma Bouchard, Shams Mehdi
Nuclear Experiment
Measurement of the $^{99}$Tc $\beta$ spectrum with Silicon Drift Detectors
Andrea Nava, Andrea Del Contrasto, Leonardo Bernardini et al. (+15 more)
The need for reliable calculations of
Nuclear Matrix Elements is compelling for the next generation of neutrinoless double-beta decay experiments. This requires
nuclear models to be validated against experimental data, such as non-unique forbidden $\beta$ decays, which have been found sensitive to details in
nuclear calculations, most importantly to the renormalization of the axial and vector currents. %, parametrized as a quenching of $g_A$ and $g_V$. We report here a measurement of the 2$^{nd}$ forbidden $^{99}$Tc $\beta$ spectrum performed for the first time with Silicon Drift Detectors, state-of-the-art
semiconductor detectors for low-energy spectroscopy. We designed a novel hybrid spectrometer using a LYSO
crystal read by a SiPM to precisely calibrate our main detector and to accurately measure the background. We then compared our measured spectrum with one obtained using cryogenic calorimeters, as well as with predictions from the Realistic Shell Model. Starting from Realistic Shell Model calculations performed with Bare decay operators, we carried out a
Bayesian analysis to extract the average quenching factors required to reproduce both the measured spectral shape and the experimental half-life, obtaining $q_{g_A}=0.40(1)$ and $q_{g_V}=0.47(1)$. These values quantify the average renormalization of the axial and vector currents, respectively, and were compared with those predicted by RSM calculations employing Effective decay operators, thereby providing a
benchmark for assessing the ability of the model to describe the second-forbidden $\beta$ decay of $^{99}\mathrm{Tc}$. More broadly, this comparison tests the reliability of the theoretical framework also used to predict $0\nu\beta\beta$
nuclear matrix elements.
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All authors Andrea Nava, Andrea Del Contrasto, Leonardo Bernardini, Matteo Biassoni, Tommaso Bradanini, Chiara Brofferio, Marco Carminati, Silvia Capelli, Francesco Cappuzzello, Manuela Cavallaro, Massimiliano Clemenza, Giovanni De Gregorio, Giulio Gagliardi, Giorgio Grosso, Nunzio Itaco, Irene Nutini, Alessia Pozzi, Nicola Zorzi
General Relativity and Quantum Cosmology
Effective Field Theory of Gravity in Relativistic Media
Beka Modrekiladze
We develop an effective field theory of
gravity in relativistic media. Integrating out the medium leaves
vacuum gravity with updated Feynman rules: a graviton propagator dressed by the stress-energy two-point function of the environment, medium-induced bulk graviton vertices from higher correlators, and generalized worldline couplings encoded in matched Wilson coefficients. The diagram
topologies are unchanged from
vacuum, so different media (perfect fluids, collisionless matter, coherent scalar fields such as wave dark matter) are not different theories but different correlators inserted into the same diagrams. We derive the in-medium rules for a relativistic fluid and obtain the full 1PN Einstein-Infeld-Hoffmann potential, the 1PN Stokes drag, the gravitational self-energy and a generalized Christodoulou
memory whose new tensor structure records the orientation of the medium's anisotropy, turning the permanent strain into an $\textit{astrophysical weathervane}$. The same rules activate phenomena forbidden in
vacuum: the sound pole converts the
symmetry-protected, non-running black-hole Love number into a resonant, running one, and graviton splitting $h\to hh$ is open into the longitudinal branch of the dressed propagator, and gives the transverse graviton a width, $\Gamma=G_N\omega^3(1-c_s^2)^2/120c_s^3$, a $\textit{gravitational opacity}$ set by the sound speed. The same vertex makes a graviton suffer dynamical friction. We assess observational prospects, from dephasing and
tidal resonances within reach of the Einstein
Telescope and LISA to proof-of-principle
memory and opacity signatures.
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Mesoscale and Nanoscale Physics
Fast universal parametric spin control in an acoustically modulated quantum dot
Mateusz Kuniej and Michał Gawełczyk
Quantum communication, distributed computing, and hybrid architectures rely on nodes enabling coherent control of
qubits and coupling to propagating
quantum modes. While
semiconductor quantum-dot (QD)
spins couple to microwave and optical
photons, weak interaction with mechanical waves has limited the integration of single-QD
spin qubits into on-chip, acoustically coupled hybrid systems. The existing theory of acoustic QD
spin control suffers from a limited range of rotation-axis angles, enforcing complex realizations of gate primitives and long gate times, leaving little margin against decoherence from trion decay and quasi-static
nuclear-
spin noise. We propose parametric control that overcomes these problems. We use far-detuned optical coupling to a trion state to dress and thus mix
spin states, combined with acoustic modulation of the optical transition energy. Instead of relying on direct acoustic resonance with the
spin splitting that leads to significant bottlenecks, we induce
spin rotations parametrically via resonance with the dressed-
spin splitting. We thus develop a
spin analog of the “swing-up” charge-state excitation. Our scheme provides fast universal
qubit control with nearly arbitrary rotation axes. Our ${\sim}$155 ps Pauli-$X$ gate duration is ${\sim}290\times$ faster than in the previous acousto-optical formulation and ${\sim}14\times$ faster than optical Faraday-geometry
spin rotation. The parametric scheme naturally enables higher-harmonic processes. Numerical simulations for ${\sim}44$ GHz acoustic driving show average gate fidelity $\ge99.9\%$ even for uncooled
nuclear-
spin environments of GaAs and InAs QDs for trion lifetime $\gtrsim1.25$ ns. These metrics suggest practically usable control and may introduce a
spin-
phonon interface with high interaction rates, versatility, and multi-
phonon processes, essential for future acoustically coupled hybrid architectures.
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Mesoscale and Nanoscale Physics
First principles calculations of electric-field-driven topological phase transitions in silicene, germanene and stanene
Julián Antonio Villarreal Murúa, Pablo Roura-Bas, Javier Daniel Fuhr et al. (+1 more)
The emergence of two-dimensional topological materials, particularly the group-14 monolayers known as silicene, germanene, and stanene has opened promising pathways for next-generation nanoelectronics and spintronics. Their buckled honeycomb structure and strong
spin-orbit coupling allow for bandgap engineering via a perpendicular electric field, leading to topological phase transitions (TPTs) from non-trivial to trivial insulating states. However, precise determination of the critical electric field $E_z^{\text{cr}}$ at which these transitions occur remains challenging, with tight-binding models often underestimating these values. Here, we present a first-principles framework that combines density-functional theory (DFT), maximally localized Wannier functions, and
evolution of the Wannier charge centers (WCC) to accurately characterize TPTs in silicene, germanene, and stanene through the $\mathbb{Z}_2$ topological invariant. In contrast to earlier work, at each electric-field strength we run fully self-consistent ab initio simulations to obtain the screened electronic structure, accounting for the material's dielectric response from both electrons and ions. From these converged results we construct a Wannier tight-binding
Hamiltonian at each electric field strength, which then enables a gauge-invariant calculation of the $\mathbb{Z}_2$ topological invariant. This methodology yields significantly more accurate numerical predictions of $E_z^{\text{cr}}$, $0.020$ and $0.250$ V/Å for silicene and germanene, respectively. Compared to previous approaches, our framework delivers a marked quantitative improvement for predicting topological phase boundaries, essential for guiding the design of topological field-effect transistors and electrostatically controlled
quantum devices based on two-dimensional materials.
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All authors Julián Antonio Villarreal Murúa, Pablo Roura-Bas, Javier Daniel Fuhr, Ricardo Faccio
Quantum Physics
Hawking Radiation in non-Hermitian Microscopic Analogues
Diego F. Munoz-Arboleda, Cristiane Morais Smith and Marcus Stålhammar
Non-Hermitian systems have recently emerged as a convenient platform to realize black-hole physics. Here, we propose a microscopic open
quantum system, namely a fermionic tight-binding chain coupled to Markovian reservoirs, which emulates black-hole properties. The resulting quadratic Lindbladian admits an effective non-Hermitian limit that produces a gain and loss
lattice model with a non-reciprocal next-nearest-neighbor hopping. The rapidity spectrum of the full Lindbladian forms tilted exceptional cones that define an effective Painlevé-Gullstrand geometry and separates into black-hole and white-hole sectors, while steady-state particle densities and currents retain clear signatures at the horizon positions. We then analyze the effective non-Hermitian
Hamiltonian that arise from the microscopic
quantum system. The biorthogonal flux identifies the outgoing exterior and interior channels. Finally, we introduce a fermionic Gaussian Nambu extension and formulate Hawking-pair witnesses through frequency-resolved scattering, nonlocal density-density correlations, and anomalous Hawking-partner amplitudes. The resulting correlations display analogue Hawking radiation signatures, while the frequency-resolved Hawking-partner correlations satisfy the fermionic covariance-positivity constraint. These results establish a connection between microscopic open-system dynamics, emergent non-Hermitian geometry, and fermionic many-body probes of analogue Hawking radiation.
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High Energy Physics (Theory)
Equation of State of a Strongly Coupled Perfect Fluid with Spin from Holography
Andres Anabalon and Horatiu Nastase
We derive the equation of state of a strongly coupled relativistic perfect fluid with finite
spin in $2+1$ dimensions using holography. The dual gravitational description is provided by a spinning black hole in $AdS_4$, whose Hawking temperature, angular velocity, and Bekenstein-Hawking
entropy determine the thermodynamic properties of the boundary fluid. We obtain the equation of state and analyze its local thermodynamic stability, finding a critical rotation above which the fluid becomes thermodynamically unstable providing a bound for the rotation of a strongly coupled
quark gluon plasma at temperature $T$ and angular velocity $\omega$ given by $\frac{4\pi T}{\omega}> 2.77239$. Remarkably, the same gravitational solution contains a second black hole associated with a second boundary. Although this black hole is non-spinning, its dual fluid rotates and possesses a distinct, “exotic” equation of state. Our results provide a
holographic equation of state for strongly coupled matter with finite
spin and establish a direct connection between black-hole rotation, intrinsic angular momentum, and the thermodynamic stability of relativistic fluids.
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Solar and Stellar Astrophysics
Calibration of the Next Generation Palomar Spectrograph as a Stellar Speedometer
Pranav Nagarajan and Kareem El-Badry
We calibrate the Next Generation Palomar Spectrograph (NGPS) for precision
stellar radial-velocity (RV) measurements using repeated observations of 24
Gaia-ESO RV standards spanning $G=11$-$18$. Because NGPS is mounted at the Hale
telescope's Cassegrain focus, changes in instrumental flexure produce wavelength-solution shifts of tens of km s$^{-1}$, with substantial time and wavelength dependence. We develop a pipeline that measures these shifts directly from each science exposure, using telluric absorption features in the R and I channels and the [O I] 5577 Å sky-emission line in the G channel. This approach eliminates the need for frequent on-sky arc calibrations. The resulting wavelength-dependent flexure corrections reduce the median absolute discrepancy relative to
Gaia-ESO RVs from tens of km s$^{-1}$ to 1.6 km s$^{-1}$. Telluric absorption provides substantially more reliable flexure calibration than sky emission lines, which do not track point-source illumination of the slit. The I channel, which contains both many telluric lines and strong photospheric lines across a range of spectral types, generally yields the most stable RVs. The achieved precision remains above the
photon-noise limit, indicating that NGPS RV performance is currently limited by calibration and modeling systematics. These results demonstrate that NGPS is well-suited for accurate and precise
stellar RV measurements across a wide range of astrophysical studies.
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High Energy Astrophysical Phenomena
Rapid radio variability in the $z\sim7$ blazar VLASS J0410$-$0139: Indication of a hidden population of weak radio jets at Cosmic Dawn
Silvia Belladitta, Eduardo Bañados, Anniek J. Gloudemans et al. (+7 more)
Doppler boosting allows blazars to be detected out to high-$z$, making them promising probes of the intergalactic medium through the 21 cm forest. We report 0.144$-$11 GHz observations of the most distant known blazar, VLASS J041009.05$-$013919.88 at z$\sim$7, obtained with the upgraded
Giant Metrewave
Radio Telescope (uGMRT), the LOw Frequency ARray (LOFAR) and the Very Large Array (VLA). The first uGMRT epoch (300$-$820 MHz, April 2023) revealed an inverted
radio spectrum which, combined with earlier (2021$-$2022) VLA data (1.5$-$11 GHz), unveiled a double-peaked spectrum potentially indicative of multi-epoch jet activity. A second uGMRT campaign (August 2023), simultaneous with new VLA observations (1.5$-$11 GHz), instead revealed a flat low-frequency and a peaked high-frequency spectrum, ruling out this interpretation. While limited by the two uGMRT epochs, variability analysis favors intrinsic jet processes, indicating a highly relativistic, closely aligned jet ($\theta<3$ deg, $\delta>19.3$, $\Gamma>9.7$). The equipartition
magnetic field ($> 1$ mG) exceeds the equivalent
Cosmic Microwave Background field at $z\sim7$ (0.2 mG), indicating synchrotron losses dominate. The inferred Doppler boosting ($\delta>19.3$) implies that J0410$-$0139 is intrinsically
radio-weak. As a blazar, it traces a much larger parent population of
radio quasars at $z\sim7$, detectable only with deep ($\leq \mu$Jy) next-generation
radio observations. LOFAR 144 MHz observations (April and July 2024) yielded $\sim$2 mJy, well below the $\sim$8 mJy predicted from uGMRT epochs, confirming strong variability at rest-frame $\sim$1 GHz. Low-frequency monitoring will be crucial for identifying high
radio intensity states suitable for future 21 cm forest studies.
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All authors Silvia Belladitta, Eduardo Bañados, Anniek J. Gloudemans, Timothy W. Shimwell, Emmanuel Momjian, Huib Intema, Chiara Mazzucchelli, Christian Fendt, Bhargav Vaidya, Fabian Walter
High Energy Physics (Phenomenology)
Macroscopic dark matter constraints for extended mass functions
Zachary S. C. Picker, Andrew Buchanan, Melissa Diamond et al. (+1 more)
We compile and recompute a subset of the landscape of constraints for macroscopic dark matter (macros), explicitly including the dependence on the fraction of dark matter in macros $f_{\rm dm}$. This allows us to map these constraints to scenarios with extended mass functions for the macros, which is a generic outcome for many of the assembly processes relevant to macro formation. We compute a number of examples of constraints for extended mass functions, finding that in many cases, wider mass functions can be severely constrained by just the interactions of the tails of the distributions. Finally, we present the code and data required for computing these limits and generating these plots in a publicly accessible repository.
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All authors Zachary S. C. Picker, Andrew Buchanan, Melissa Diamond, Joseph Bramante
Quantum Physics
Computing 256-bit elliptic curve discrete logarithms in 26 days on a fault-tolerant trapped-ion quantum computer with 20,000 qubits
Thomas Häner, Felix Tripier, Jacob Young et al. (+11 more)
One of the strengths of our recently proposed Walking Cat Architecture for a trapped-ion
quantum computer is that it is straightforward to extend and optimize for a specific application. As a proof-of-concept, here we present such optimizations for solving the $256$-bit
elliptic curve discrete logarithm problem (ECDLP) on $\mathtt{secp256k1}$, which is the
elliptic curve used by blockchain technologies such as Bitcoin, using Shor's
algorithm. We optimize the
circuits from Schrottenloher's recent work and arrive at a logical
quantum circuit for solving the ECDLP using about $1450$
qubits and $40\cdot 10^6$ Toffoli gates, with a rigorous lower bound on the logical-level success probability that holds with confidence at least $1-2^{-128}$. Using our compilation toolchain with manual optimization of the logical layout and integrated routing, we produce estimates for the logical measurement depth and the required number of physical
qubits by compiling all components to measurement schedules that obey the architectural constraints. A key ingredient is a fast CCZ magic-state factory and a depth-one CCZ state injection, reducing the execution time of CCZ gates by a factor of $31$. We increase the logical-measurement parallelism using non-overlapping cat-based measurements in parallel, and we leverage the recently proposed logical CliNR protocol to speed up Clifford operations. To reduce the
qubit overhead, we introduce a more efficient loss correction protocol, design a layout that allows us to recycle the CliNR ancilla
qubits, and provision reusable cat-state resources according to the
circuit's peak measurement parallelism. All results and optimizations combined, we conclude that a trapped-ion
quantum computer based on our architecture can solve the ECDLP on $\mathtt{secp256k1}$ in approximately 25.7 days using 19,397 physical
qubits with an estimated success probability of $63\%$.
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All authors Thomas Häner, Felix Tripier, Jacob Young, Michael Naehrig, Andrii Maksymov, Safwan Alam, Dmitri Maslov, Matthew Parrott, Yvette de Sereville, Jordan Sullivan, Mark Webster, Nicolas Delfosse, John Gamble, Martin Roetteler
Astrophysics of Galaxies
LOFAR radio properties of quasars hosting Extremely High Velocity Outflows
Amy L. Rankine and Paola Rodríguez Hidalgo
Quasar winds are a potential contributor to the
radio emission observed in the so-called '
radio-quiet'
quasars. Extremely High Velocity
Outflows (EHVOs), with bulk velocities >0.1c, represent some of the most energetic of these winds. In this work, we investigate the
radio properties of
quasars hosting EHVOs in order to assess whether such high-velocity winds contribute to the observed
radio emission. We cross-match the catalogue of EHVOs from the Sloan Digital Sky Survey with the high-sensitivity Low-Frequency Array (LOFAR) Two-metre Sky Survey (LoTSS) Data Release 3. We find that EHVO
quasars exhibit a significantly higher
radio-detection fraction of 38 per cent compared to an underlying parent
quasar population at 24 per cent. By constructing control samples using nearest-neighbour matching, we show that matching the C IV emission line blueshift alone is sufficient to reproduce the elevated
radio-detection fraction in a global sense; however, differences still remain in the
radio-detection fraction as a function of C IV emission blueshift between the EHVO distribution and any matched sample, suggesting that some additional mechanism is at play. Furthermore, composite spectra reveal no significant differences in the ultraviolet absorption profiles between
radio-detected and
radio-undetected EHVOs, although we identify a mild positive correlation between maximum
outflow velocity and
radio luminosity. Our results suggest that EHVOs likely represent a subset of the
quasars which host fast winds that are observed along particular lines-of-sight, and that
radio emission associated with such winds remains a plausible mechanism.
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Mathematical Physics
Distance Energies and Negative Type of Flat Tori
Ye Zhou
Let \(T_\Lambda=\mathbb R^d/\Lambda\), \(d\geq2\), be a flat
torus with quotient metric \(\rho_\Lambda\), and consider the distance energies \(I_\alpha(\mu)=\iint \rho_\Lambda(x,y)^\alpha\,d\mu(x)\,d\mu(y)\) of Borel probability measures \(\mu\). We prove a quantitative
Fourier signature of the cut locus: for every Voronoi facet and every \(\alpha>0\), there is a sequence of dual-
lattice frequencies approaching the facet normal along which the
Fourier coefficients of \(\rho_\Lambda^\alpha\) are positive, with an explicit leading asymptotic determined by the facet. As direct consequences, Haar measure is not a local maximizer for any positive distance power, even among smooth densities, and every flat
torus of dimension at least two has supremal negative type and generalized roundness zero. We then solve the global maximization problem for two classes of flat
tori. On an orthogonal rectangular
torus, the maximizers undergo a transition at \(\alpha=2\): for \(1\leq\alpha<2\) they are the translated uniform measures on the two-torsion subgroup; at \(\alpha=2\) all balanced couplings on translates of that subgroup are extremal; and for \(\alpha>2\) only equally weighted diametral pairs remain. On the regular hexagonal
torus, the maximizers are precisely the uniform measures on translates of a distinguished cyclic subgroup of order three for every \(\alpha\geq1\).
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High Energy Physics (Phenomenology)
High-sensitivity Ultralight Dark Matter detector: Parametrically Amplified Casimir Devices
Muping Chen, Hideo Iizuka, Kyohei Mukaida et al. (+2 more)
We propose the use of sphere-and-plate Casimir force measurement setups to detect ultralight vector dark matter. We demonstrate that sub-picometer signals can be parametrically amplified to be detectable. We present a novel improvement that allows the continuous tuning of the natural frequency of the system, opening new research opportunities at the submicron scale. We show that the improved setup can determine the dark matter mass with high accuracy, significantly expand the detectable mass range, and achieve the best sensitivity to date in the $8\times10^{-14}\sim1\times10^{-12}{\rm~ eV}$ mass range.
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All authors Muping Chen, Hideo Iizuka, Kyohei Mukaida, Kazunori Nakayama, Burkhant Suerfu
Solar and Stellar Astrophysics
Deep H$\alpha$ Imaging Survey of IC 348 with the Hubble Space Telescope: I. Accretion Properties of Stellar and Substellar Objects
Lillian Yushu Jiang, Brendan P. Bowler, Yifan Zhou et al. (+5 more)
Accretion governs the growth of young
stars and the early
evolution of their circumstellar disks, yet population-level measurements of
accretion are often hampered by heterogeneous diagnostics and by samples preferentially selected toward disk-bearing or accreting objects. This can impact the mass
accretion rate-
stellar mass ($\dot{M}$-$M_\star$) relation, particularly at substellar masses. We present a uniform analysis of
accretion in the $\sim$2 Myr-old
star-forming cluster IC 348 based on deep Hubble Space
Telescope F656N imaging. Using H$\alpha$ excess as a single, homogeneous
accretion tracer, we derive
accretion rates and robust upper limits for 200 cluster members spanning the
stellar to substellar mass regime ($3\ M_\odot$ to $4\ M_{\rm Jup}$).
Accretion is detected in $37\pm3\%$ of the sample, with fractions of $34\pm4\%$ among
stellar members and $46\pm6\%$ among substellar objects. For accretors alone, the inferred $\dot{M}$-$M_\star$ relation is consistent with those measured in similarly aged regions such as Lupus. In contrast, including weak accretors and non-detections increases the scatter and flattens the slope while lowering the intercept, demonstrating the strong influence of the low-
accretion tail on population-level
accretion relations. For free-floating planetary-mass objects in IC 348, extrapolating the accretors-only fit overpredicts $\dot{M}$ by approximately an order of magnitude compared to the fit that includes upper limits, which instead implies mass
accretion rates of $<10^{-12}$ $M_{\odot}\ \mathrm{yr}^{-1}$. These results show that sample selection, specifically whether the sample is restricted to disk-bearing or accreting targets, or instead is drawn from a complete membership census, is a dominant factor shaping population-level
accretion relations across a wide dynamic range in
stellar mass.
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All authors Lillian Yushu Jiang, Brendan P. Bowler, Yifan Zhou, Adam L. Kraus, Sean M. Andrews, Lynne A. Hillenbrand, Michael J. Ireland, Zhaohuan Zhu
Earth and Planetary Astrophysics
Rotational broadening of exoplanet spectra in arbitrarily oriented systems: Application to reflected light
Sophia R. Vaughan and Laura Kreidberg
Exoplanet reflection spectra contain a wealth of information, which we are now beginning to access. At a high spectral resolution, the rotation of both the
star and the
planet affects the shape of the reflected spectral lines. This effect must be accounted for in high-resolution analyses and could be used to measure the orbital
alignment of systems. In this work, we derive the rotational broadening kernels for arbitrarily aligned systems, both for the
stellar spectrum viewed by the
planet and for the reflected component of the
planet's spectrum. We then determine the relation between the parameters of the kernels and the standard orbital parameters of an
exoplanet system. Finally, we show examples of these kernels, compare them with previous models, and investigate the limitations imposed by our assumptions. We find that the difference in the rotational broadening of a non-aligned system relative to the broadening expected from a prograde aligned orbit can be of the order of 50 km s$^{-1}$. We also highlight how the equations and kernels presented in this work could be modified for other uses, such as thermal emission spectra.
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Astrophysics of Galaxies
Halo mass, star formation, and morphology in galaxies: A morphology-dependent connection between halo environment and star formation activity
G. Mountrichas, F. Shankar, F. J. Carrera et al. (+1 more)
Understanding the mechanisms responsible for quenching
star formation in
galaxies requires disentangling the roles of internal structure and large-scale environment. We investigate how
galaxy morphology and specific
star formation rate (sSFR) relate to the typical masses of host dark-matter
halos (DMHs), and whether the
halo–
star formation connection depends on morphology. We analyse non-active
galaxies in the VIPERS and Stripe 82 fields at $0.5 \leq z \leq 1.2$, combining DESI-based Sérsic classifications with
stellar masses and SFRs from spectral energy distribution fitting.
Galaxies are separated into disc- and bulge-dominated systems and divided into
quantile-based sSFR bins designed to minimise
stellar-mass differences between morphologies. Each bin is characterised by its median $\Delta{\rm MS}=\log {\rm SFR}-\log {\rm SFR}_{\rm MS}$, and characteristic DMH masses are inferred from projected
galaxy cross-correlations. The
halo-mass relation with
star formation activity depends strongly on morphology: disc-dominated
galaxies show little variation in
halo mass across the probed $\Delta{\rm MS}$ range, whereas bulge-dominated
galaxies occupy lower-mass
halos at high $\Delta{\rm MS}$ and higher, mutually consistent
halo masses toward lower $\Delta{\rm MS}$. These trends are unlikely to be driven mainly by
stellar-mass differences. Typical
halo mass alone therefore does not map cleanly onto quiescence; instead, the connection between
halo environment and
star formation activity is stronger in bulge-dominated than in disc-dominated
galaxies.
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All authors G. Mountrichas, F. Shankar, F. J. Carrera, A. Georgakakis
Solar and Stellar Astrophysics
Unresolved Binary Systems in the Rubin Era I: An Autoencoder Framework for Binary Identification Applied to 47 Tucanae
Tobias Géron, Alexander Laroche, Joshua S. Speagle et al. (+1 more)
Binary systems are extremely common and influence many areas of astrophysics, such as
stellar evolution and cluster dynamics. In this work, we introduce flexAE, a framework that combines a classical autoencoder architecture with a dedicated classifier component. It is designed to distinguish between single
stars and binary systems based on their broadband spectral energy distributions, using all available photometry simultaneously while accounting for observational uncertainties. We demonstrate the capability of flexAE by using it to identify unresolved main sequence binaries in the outskirts of the 47 Tucanae globular cluster (NGC 104) with photometric data from the Vera C. Rubin Observatory. We train the model on a simulated sample of single
star and binary systems created with
stellar atmosphere models. The model accurately reconstructs the photometric input features and achieves a classification accuracy of 0.85 on the simulated test set. We then apply the trained model to a sample of 1,424 cluster members found in Rubin DP1 with reliable $gri$ photometry, of which 32 are identified by the model as unresolved main sequence binaries. This corresponds to an observed binary fraction of $2.2^{+0.5}_{-0.3}$%. We estimate that the intrinsic main sequence binary fraction lies between $3.7^{+0.8}_{-0.5}$% and $7.5^{+1.5}_{-1.1}$%. The binary fraction stays constant between 18-36 arcmin (5.7-11.4 half-light radii) from the cluster center. We highlight that flexAE can be easily adapted for other use cases. This makes flexAE well-suited for large-scale binary classification in upcoming wide-field surveys, such as Rubin LSST. The code is publicly available at https://github.com/tobiasgeron/flexAE.
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All authors Tobias Géron, Alexander Laroche, Joshua S. Speagle, Maria R. Drout
Astrophysics of Galaxies
A direct measurement of the tilting rate of the Milky Way disc
Guillaume F. Thomas, Benoit Famaey, Alicia Rivero et al. (+2 more)
The Milky Way disc is typically described, at lowest order, as a flattened rotating
stellar component with a fixed
spin axis. However, interactions and mergers with smaller
galaxies are expected to have an impact on the disc properties. Such interactions can leave long-lasting signatures within
galactic discs, including warps and corrugation waves that have already been detected in the Milky Way, but also a slow reorientation of the disc known as tilting, which has never been directly measured up to now. Here, using the vertical proper motions of 110 million
stars from the
Gaia DR3 catalogue, we present the first-ever direct measurement of the tilting rate of our
Galaxy's disc. The detected signal of 14 +/- 2 deg/Gyr around the Sun-
Galactic Centre axis is statistically significant and is consistent with typical values found in cosmological simulations. By comparing our measurements with high-resolution tailored simulations, we infer that the observed tilting rate is likely the long-term consequence of a major
accretion event that occurred around 8-10 billion years ago. The signal is consistent with the merger of a massive satellite
galaxy on a retrograde orbit with a ratio of about 1:4, probably associated with the
Gaia-Enceladus/Sausage event. These results provide independent evidence for a key episode in the Milky Way's formation history and introduce a new way to reconstruct the assembly histories of disc
galaxies from their present-day motions.
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All authors Guillaume F. Thomas, Benoit Famaey, Alicia Rivero, Giuseppina Battaglia, Rodrigo Ibata
High Energy Physics (Phenomenology)
Energy-energy correlators and color decoherence from a generating functional
Yacine Mehtar-Tani
Using jet calculus at leading-logarithmic accuracy, we develop a generating-functional approach to describe the hard-collinear sector of jets propagating through the
quark-
gluon plasma. This framework yields coupled
evolution equations for the jet
nuclear modification factor and energy-energy correlators (EECs). We first construct the EEC
evolution in the fully incoherent regime, and then derive
evolution equations that account for the transition from the coherent to the incoherent limit in the large-$N_c$ limit. Furthermore, we show that combining the EEC with the jet
nuclear modification factor provides complementary sensitivity to the overall jet suppression and to medium-induced modifications of the jet's internal structure. This framework therefore offers a way to constrain the magnitude and
flavor dependence of jet energy loss, together with the medium resolution angle governing color decoherence.
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High Energy Physics (Theory)
Robin Löwenberg and Julian Sonner
We propose an analog
quantum-simulation protocol based on a
lattice of atomic ensembles and time-averaged Floquet dynamics to construct the four-body potentials that typically appear in bosonic BFSS-like
matrix quantum mechanics. In contrast to gate-based digital implementations requiring deep
circuits, our approach generates the target model through a fixed set of control stages per Floquet cycle, keeping the number of consecutive
unitaries constant with respect to the
matrix size $N$. The principal scaling cost in our construction is given by the frequency range required to control the growing
lattice. We show that this cost grows at most as $\mathcal{O}(N^3)$, giving a
polynomial scaling route to large$-N$, attractive to experimental implementation. Additionally, we demonstrate that the coupling parameter can be tuned beyond $\mathcal{O}(1)$, enabling the simulation of strong-coupling physics necessary for
holographic phases.
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Cosmology and Nongalactic Astrophysics
How Cluster Pressure Profiles Scale: Mass, Redshift, and Intrinsic Scatter
S. Andreon and F. Castagna
[shortened] The thermal pressure profile of the intracluster medium is critical for cluster cosmology and understanding
galaxy-cluster astrophysics. We determine the population-averaged pressure profile of Sunyaev-Zel'dovich (SZ) selected clusters, characterize its intrinsic scatter, and measure its scaling with mass and
redshift. We select 60 clusters from the South Pole
Telescope (SPT) SZ catalog with $0.08<z<0.6$, requiring high signal-to-noise and 5 element resolution on Planck-SPT Compton-$y$ maps. We model spherical three-dimensional pressure profiles from the Compton-$y$ maps using a hierarchical
Bayesian framework with restricted cubic splines. We adopt an updated weak-
lensing-calibrated Compton-$Y$–mass scaling relation, effectively removing hydrostatic mass bias from the inferred masses. Our model accounts for cluster-to-cluster profile variations, line-of-sight foreground and background contributions, and outliers from intrinsically distinct clusters or projection effects. The code is publicly available. We derive the population-averaged pressure profile and find minimal intrinsic scatter at intermediate radii ($0.4 \le r/r_{500} \le 0.7$). Our pressure profile is approximately 40% lower than previous estimates at all radii, due to the unbiased mass scaling. We find suggestive, though not conclusive, evidence that the adopted mass dependence may require revision by removing the additional $M^{0.12}$ scaling introduced by Arnaud et al. 2010. We constrain departures from self-similar
evolution in the mean profile to less than 0.1–0.2 dex and
evolution of the intrinsic scatter to less than 8% per $\Delta z=0.1$.
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Astrophysics of Galaxies
Discovery of Very Minor Merger-Induced Star-forming Clumps at $z=3.33$ with JWST
Alexander de la Vega and Bahram Mobasher
High-
redshift galaxies often contain ”clumps:” compact, $\sim$kpc-scale regions of intense
star formation. These substructures make up significant fractions of the masses and
star-formation rates of their host
galaxies and are expected to affect the morphologies of their hosts, such as by building up bulges. Studying clumps can therefore inform theoretical models of
galaxy evolution. Two main mechanisms have been proposed for their formation: gas fragmentation from disk instabilities and compression of gas during gravitational interactions with other
galaxies. In the latter, only mergers with mass ratios greater than 1:10 have been considered. Here, we report James Webb Space
Telescope spectroscopy and imaging of JADES 1034862, a
galaxy at $z_{\textrm{spec}} = 3.33$, which hosts a clump that formed during an interaction with a companion with a
stellar mass that is $\approx28$ times lower than the host. From fits to the spectral energy distributions of the clump and the companion, it is found that both of their
star-formation histories rose sharply in the most recent 100-300 Myr, during which the clump formed $\sim10^{7.2} \ M_{\odot}$ in
stars and currently makes up $\approx10\%$ of the total
star-formation rate of its host. Given the higher frequency of mergers with low mass ratios ($<1:10$) to those with higher ratios, we infer that a substantial fraction of high-
redshift clumps could have formed through weak gravitational interactions.
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Instrumentation and Methods for Astrophysics
Fast Lensing And Sub-minute High-accuracy photometry (FLASH) with JWST: Pipeline and Primordial Black Hole Microlensing Constraints from M31
David Rubin and Istvan Szapudi
Minute- and sub-minute microlensing provides a direct probe of compact dark matter at asteroid-mass scales, where
primordial black holes with MPBH <~ 10^-10 Msol would produce short-duration, finite-source-suppressed amplifications of
stars in extragalactic fields. To enable these measurements, we present FLASH: Fast
Lensing And Sub-minute High-accuracy photometry with JWST, a pipeline designed to recover such events from JWST/NIRCam imaging by preserving detector-ramp time information and performing high-precision crowded-field photometry. FLASH begins from Level 1 NIRCam data products, applies microlensing-oriented detector calibration (including improved treatment of non-linearity and position-dependent detector calibration), and extracts forced multi-band light curves in crowded fields. We apply the pipeline to two public JWST/NIRCam
datasets targeting the disk of M31 with 21.5 s cadence: GO-4735 and GO-2609. Although these observations are suboptimal as a microlensing survey, they provide a stringent test of JWST time-domain performance in a high-surface-brightness, crowded
stellar field. Using these data with our own microlensing simulations, we derive the first JWST-based microlensing constraints toward M31, finding fPBH <~ 100 for MPBH~ 10^-9 Msol. Our results demonstrate that JWST is a competitive platform for high-cadence microlensing and that a dedicated, continuous NIRCam monitoring program could substantially improve constraints on compact dark matter below the current ground-based frontier.
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High Energy Physics (Phenomenology)
The Colors of Jet Quenching
Hannah Bossi, Maxence Larose and Yacine Mehtar-Tani
We combine inclusive jet
nuclear modification factors with energy-energy correlators to perform a data-driven extraction of the
quark and
gluon quenching factors and the medium resolution scale from the small-angle region. Taking coherent energy loss as a null hypothesis, we find jet quenching factors incompatible with Casimir scaling. Incorporating color decoherence through
antenna energy loss improves the description of the data and restores Casimir scaling, providing evidence that the
quark-
gluon plasma partially resolves the internal structure of jets in heavy-ion collisions.
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Solar and Stellar Astrophysics
The youngest white dwarf companion to a millisecond pulsar: Insights from NGC 362D
Greta Ettorre, Emanuele Dalessandro, Mario Cadelano et al. (+7 more)
We report on the identification of the optical counterpart to the recently discovered millisecond
pulsar (MSP) NGC362D in the
Galactic globular cluster NGC362 based on deep, multi-band, and multi-epoch Hubble Space
Telescope observations. Our analysis robustly shows that this object is a very low-mass ($\sim0.18 M_{\odot}$) He white
dwarf (WD) still in the pre-cooling phase. Interestingly, a detailed comparison with updated binary
evolution models indicates that this object completed the mass-transfer phase only recently ($\sim0.6$ Gyr ago), thus strongly suggesting that COM-NGC362D is the youngest WD companion to a MSP identified to date. Remarkably, in this respect, the photometric properties of NGC362D show, for the first time in this class of objects, significant wavelength-dependent variations that are consistent with the presence of residual circumstellar material. This system therefore provides a valuable test case to directly probe the immediate aftermath of the MSP recycling process and to constrain the early evolutionary stages of proto-WD companions and their
radio and optical properties. Our results suggest that residual material can produce
radio and optical signatures that mimic those of systems with non-degenerate companions, potentially leading to the misclassification of young MSPs.
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All authors Greta Ettorre, Emanuele Dalessandro, Mario Cadelano, Alessandro Ridolfi, Cristina Pallanca, Paulo C. C. Freire, Vivek Venkatraman Krishnan, Maurizio Salaris, Franca D'Antona, Rouhin Nag
Cosmology and Nongalactic Astrophysics
Analytic bispectrum covariance for galaxy survey cosmology
Utkarsh Giri, Henry S. Grasshorn Gebhardt and Olivier Dore
The bispectrum of
galaxy distribution remains an underutilized statistic in cosmological data analysis. This can be attributed to mathematical and computational challenges associated with a proper modeling of the signal and its covariance. While recent theoretical advances have made it possible to analytically model the bispectrum signal and covariance using perturbation theory, a fully non-Gaussian analytical treatment of the covariance for a realistic survey with window remains elusive. The full bispectrum covariance of observed
galaxies is a non-Gaussian six-point function with each of its legs convolved with a complex window function. Although it has so far proven intractable, the problem is well-posed. In this article, we present the derivation, implementation, and validation of a numerical routine for the analytic calculation of the bispectrum covariance for a spherical window, carried out by a large
language model (LLM). The derivation uncovered terms that vanish in the windowless case but that dominate the covariance for triangles with survey scale modes. As a development
benchmark for the implementation, we used the sample covariance of the
halo bispectrum measured from 6000 fiducial Quijote
halo catalogs in real space. Over several iterations of refinement, the LLM converged on a regime-specific numerical scheme for the covariance
matrix calculation, mixing exact and approximate approaches, resulting in a highly optimized, tractable and accurate covariance across scales and shapes, using only tree-level models for the input polyspectra. Closing the loop still required human expertise, which illustrates what human-AI collaboration in research may look like in the near term.
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High Energy Physics (Theory)
Cosmology, Cluster Algebras, and $\boldsymbol{u}$
Daniel Glazer and Austin Joyce
We explore the cluster
algebra structures present in the wavefunction and correlators of conformally coupled scalar fields in de Sitter space. To connect cosmological kinematics to cluster variables, we utilize the so-called $u$-variables that appear on both sides. Since $u$-variables parameterize a rigid space, it is natural to identify the ones that appear from cosmological graphs and those that arise from cluster
algebras. This provides a mapping between kinematic variables and cluster variables. For $n$-site chain Feynman graphs, this gives a coordinate-invariant relation to $A_{2n-2}$-type cluster
algebras, while in the case of $n$-site cycle graph momentum integrands, the relevant cluster
algebra is $B_{2n-1}$, as found previously. Since kinematic variables are mapped to nonlinear combinations of cluster variables, cluster compatibility imposes strong conditions on possible symbol entries. We use this notion of compatibility to bootstrap the symbol. In the chain case, both the cosmological wavefunction and products of lower-point functions satisfy cluster compatibility, with the correlator a particular combination, so that the wavefunction and correlator share the same cluster structure. In the cycle case, however, the wavefunction appears to be uniquely selected by the cluster structure, and the correlator does not display the same compatibility as the wavefunction.
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