Solar and Stellar Astrophysics
Agentic Active Learning Meets Visual Embeddings: Finding Anomalies among 370 000 Variable Stars from ASAS-SN
Milan Pesta and Yuan-Sen Ting
Unusual light-curve morphologies can point to rare physical configurations or new phenomena, but automatic searches for anomalies are often dominated by artifacts. Separating genuine anomalies from false positives has traditionally required manual vetting, which does not scale to modern surveys. We present an active learning framework for detecting anomalies in samples of periodic variable
stars, with the vetting delegated to
multimodal large
language model
agents. The initial ranking comes from isolation forests trained on DINOv2 ViT-g/14
embeddings of phase-folded light curves. The
agents iteratively review the light-curve images of the top-ranked candidates and assign relevance scores, which are propagated through the
embedding space to prioritize the next targets. A logistic regression step then extends the search beyond label propagation, and a multi-
agent consensus review filters false positives. Using Gemini~3 Flash
agents, we applied the pipeline to $373\,646$ periodic variables from ASAS-SN Sky Patrol V2.0. Across $51$ iterations, the
agents labeled ${\sim}1\%$ of the sample in roughly $3$ hours at a cost of ${\approx}$ $$40$, yielding our final catalog of $24$ anomalies ($18$ newly reported) and $153$ potentially interesting objects. The anomalies include eclipsing binaries with extremely deep primary eclipses, high-amplitude contact binaries and pulsators, and a symbiotic nova in outburst for over two decades. At the same labeling budget, the initial ranking would have recovered only $30%$ of our catalog, while reaching its lowest-ranked anomaly would have required ${\sim}70$ times the budget. These results demonstrate the feasibility of agentic active learning for anomaly detection in existing and upcoming photometric surveys.
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Astrophysics of Galaxies
Cool CGM MgII Absorption Across the Star-Forming, Green Valley, and Quiescent Transition
Simon Xinlin Wu, Rongmon Bordoloi, Robert A. Simcoe et al. (+4 more)
We investigate the distribution and kinematics of cool circumgalactic medium (CGM) gas across the
star-forming to quiescent transition using MgII absorption for 716
galaxies spanning $0.07<z<2.7$ (169 new and 547 archival
galaxies). To compare
galaxies uniformly across 10 billion years of
cosmic time, we introduce a
star-formation offset metric ($\sigma_{\mathrm{SFO}}$), which measures a
galaxy's deviation from the
star-forming main sequence of its epoch. A key advantage of $\sigma_{\mathrm{SFO}}$ is its ability to identify transitional green valley
galaxies as a distinct population across
redshift, which would otherwise be obscured by binary
star-forming-passive classifications. We fit a virial-radius-normalized radial profile and find that the MgII absorption strength declines with increasing projected distance from the host
galaxy. The scatter around this mean profile correlates strongly with
star-formation activity: radial profile residuals correlate positively with $\log sSFR$ and $\sigma_{\mathrm{SFO}}$, with
star-forming
galaxies showing excess absorption above the profile, green-valley
galaxies showing intermediate residuals, and quiescent
galaxies falling preferentially below it. The MgII covering fraction in the inner CGM ($R/R_{200} < 0.25$) follows the same sequence, declining monotonically from
star-forming through green-valley to quiescent systems. MgII absorption kinematics are consistent with a predominantly bound cool CGM.
Star-forming
galaxies further exhibit a bimodal azimuthal dependence, with MgII absorption enhanced along both the polar and disk directions, consistent with bipolar
outflows and co-planar
accretion. Together, these results indicate that the cool CGM tracks the quenching of
star-formation in
galaxies, with $\sigma_{\mathrm{SFO}}$ revealing a gradual decline in cool gas across the green valley rather than an abrupt
star-forming-to-passive transition.
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All authors Simon Xinlin Wu, Rongmon Bordoloi, Robert A. Simcoe, Andrew J. Fox, Jessica K. Werk, Jason Tumlinson, J. Xavier Prochaska
High Energy Physics (Theory)
Color-Kinematics Duality and the Double Copy in Curved Spacetimes
Mariana Carrillo González
The double copy relates gravitational data to gauge-theory data, most sharply through color-kinematics duality for flat-space scattering amplitudes. This review surveys the extent to which this idea can be formulated beyond asymptotically flat backgrounds. After recalling the flat-space ingredients needed for comparison, we describe curved-space constructions for boundary correlators and scattering observables in AdS, dS, and other non-trivial backgrounds. We then review classical and field-level maps, including Kerr–Schild, Weyl, Cotton, twistor, and convolutional double copies. A separate part is devoted to self-dual sectors. Throughout, we emphasize both the common structures that survive from flat space and the obstructions introduced by
curvature.
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Lattice Field Theory
Direct lattice QCD calculation of the $\theta$-induced CP-violating pion-nucleon coupling
Chuan-Yang Li, Jun Hua, Jian Liang et al. (+4 more)
We present the first direct
lattice QCD determination of the $\theta$-induced CP-violating pion-nucleon-nucleon coupling $\tilde g_{\pi NN}$. Using overlap valence
fermions on three $2+1$-
flavor domain-wall ensembles at a single
lattice spacing, we calculate the forward
proton matrix element of the isovector pseudoscalar density in the $\theta$-
vacuum to first order in $\bar\theta$. The parity-mixing effect in the external nucleon states is included in the extraction. The cluster-decomposition error-reduction method is used to improve the statistical precision. A simultaneous extrapolation in the valence- and sea-pion masses, with model averaging over 7 forms based on the Akaike information criterion, gives $\tilde g_{\pi NN}=0.0306(56)(124)\,\bar\theta$ at the physical point. The first uncertainty includes the statistical and
matrix-element-fit systematic uncertainties, whereas the second reflects the spread among the extrapolation forms. Within these uncertainties, the result is consistent with the indirect determination based on the strong
neutron-
proton mass splitting. The present precision is limited primarily by the extrapolation from the relatively heavy sea-pion masses.
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All authors Chuan-Yang Li, Jun Hua, Jian Liang, Keh-Fei Liu, Long-cheng Gui, Jun Shi, Nan Wang
Cosmology and Nongalactic Astrophysics
Exact Equivalence of the Observed Redshift and the Pulsar Timing Modulation in the Infinitesimal-Pulse Limit
Matteo Magi and Jaiyul Yoo
The
pulsar timing arrays (PTA) collect the times of arrival of
radio signals from the millisecond
pulsars, and gravitational waves can modulate their arrival times. Although the PTA observable involves successive
radio pulses propagating along different light paths, its standard theoretical description at linear order in perturbations is equivalent to the Sachs-Wolfe formula for the observed
redshift, which describes the fractional change in
photon frequency along a single geodesic. While this equivalence is well known at linear order, its validity beyond first order has not been systematically addressed in the PTA literature. Here we show that, in the limit of vanishing proper-time separation between successive emission events, the timing modulation is exactly equal to the observed
redshift, without expanding the spacetime geometry. For a finite emission interval, we derive the exact relation between the timing modulation and the observed
redshift, and show that their difference is controlled by the ratio between the emission interval and the characteristic timescale over which the observed
redshift varies.
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Strongly Correlated Electrons
Raman Circular Dichroism Reveals Higher-Order Quantum Geometry of Magnons
Yong Chan Kim, Youngsu Choi, Kwang-Yong Choi et al. (+1 more)
We develop a gauge-invariant framework that relates two-
magnon Raman circular dichroism (RCD) to higher-order
magnon quantum geometry. In the
magnon band basis, the Raman operator decomposes into interband Berry connections, their covariant derivatives, and products of successive connections, generating higher-order, multi-state
geometric tensors beyond the conventional single-band
quantum metric and Berry
curvature. Applying this framework to a field-polarized Kitaev magnet, we show that higher-order
geometric tensors govern the dichroic response. Our results establish RCD as a spectroscopic probe of generalized
magnon quantum geometry.
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All authors Yong Chan Kim, Youngsu Choi, Kwang-Yong Choi, Kyusung Hwang
Earth and Planetary Astrophysics
Quantitative Links between Formation and Atmospheric Composition for Giant Planets
Yayaati Chachan, Ruth Murray-Clay and Jonathan J. Fortney
Precise atmospheric abundances of
giant exoplanets are becoming increasingly prevalent and there is a need to systematically convert these measurements into metrics that inform us about the
planets'
accretion history. We present a quantitative framework for relating atmospheric composition to the
accretion of metals and
primordial gas. This includes i) new relations that simplify and generalize the connection between atmospheric
metallicity and metal mass fraction, ii) methods for inferring the source of the metals and quantifying the quantity of metals accreted via different sources, and iii) relating the derived quantities to expectations from formation models. We also derive a new estimate of the minimum disk mass needed to form a planetary system based on the amount of excess metals accreted by a
planet, assuming that this excess originates from the drift and evaporation of pebbles at condensation fronts. This paper is accompanied by an open-source code that implements the methods presented herein.
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Quantum Physics
Bang-bang protocol for nondispersive qubit readout
Nina del Ser, Yinan Chen, Jacob Steiner et al. (+1 more)
Fast, precise, and
quantum-non-demolition (QND) readout of superconducting
qubits is a fundamental component of high-fidelity
quantum sensing and computation. Conventional approaches typically operate in the dispersive regime, where the
qubit-resonator coupling $g$ is weak compared to the detuning $\Delta$. While exhibiting good QND properties, the readout rate is limited to $\sim g^2\sqrt{N}/\Delta\ll g$, where $N$ is the number of
photons in the resonator. QND readout in the nondispersive regime, where the readout rate reaches its full potential $\sim g$, relies on parameter sweeps that may encounter resonances, leading to measurement-induced state transitions (MIST). In this work, we study a nondispersive readout protocol that replaces these sweeps by sudden quenches of the coupling constant, using a resonator that is preloaded with
photons. We call this protocol bang-bang readout, and show that it realizes single-shot projective measurements. The fidelity and QNDness of the
qubit post-measurement are remarkably high, with an error that decreases like $1/N$. We show that the protocol can also be implemented without preloading the resonator by instead strongly driving the
qubit, e.g., with a classical flux drive.
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All authors Nina del Ser, Yinan Chen, Jacob Steiner, Gil Refael
General Relativity and Quantum Cosmology
Primordial spectra from modified Bekenstein-Hawking entropy law
Marco de Cesare, Giulia Gubitosi and Varun Kushwaha
Many approaches to
quantum gravity predict logarithmic corrections to the Bekenstein-Hawking
entropy. Within the spacetime-thermodynamic description of
gravity, such corrections lead to modified gravitational field equations. We study their effect on
primordial perturbations during standard single-field slow-roll inflation. We derive the
evolution equation for the comoving
curvature perturbation and show that it retains the standard Mukhanov–Sasaki form, with the
quantum-
gravity correction entering through the time-dependent effective frequency. We compute the scalar and tensor
primordial spectra at next-to-next-to-next-to-leading order ($\mathrm{N}^3\mathrm{LO}$) in the Hubble-flow parameters, keeping the leading contribution from the logarithmic correction. The scalar spectrum remains nearly scale invariant, but the
quantum-
gravity correction shifts its tilt and runnings. Free tensor modes still propagate as in general relativity, although on the
quantum-
gravity-corrected background. This different response of the two sectors shifts both the tensor-to-scalar ratio and the single-field consistency relation, which provide the starting point for tracing the model's signatures through the post-inflationary
evolution and into the CMB.
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High Energy Physics (Phenomenology)
When the HL-LHC is blind, LISA is deaf (but not vice versa): 2HDM collider-cosmology synergies
Stefano Moretti, André Pousette and Carlo Tasillo
Extensions of the Standard Model scalar sector can render the electroweak phase transition first-order and thereby provide the departure from thermal
equilibrium required for electroweak baryogenesis, while at the same time sourcing a
stochastic gravitational wave (GW) background in the milli-Hertz range. In this work, we investigate electroweak phase transitions in the CP-conserving type-I two-
Higgs-doublet model (2HDM), focusing on the interplay between
collider constraints at the HL-LHC and the projected sensitivity of LISA. We compute the expected GW background due to strong first-order electroweak phase transitions and perform extensive Monte Carlo scans over the
collider-viable model parameter space. We find that GW signals within reach of LISA arise almost exclusively in regions of parameter space that necessarily predict observable deviations at the HL-LHC, in particular through the $H \to ZZ$ decay channel of the heavy CP-even and neutral
Higgs state with $m_H \simeq 180\text{--}250 \, \text{GeV}$. Our results highlight the decisive complementarity between
collider and GW probes and show that the largest parts of the 2HDM parameter space relevant for phase transition signals at LISA can already be tested by HL-LHC. A possible future discovery of 2HDM states at the HL-LHC, however, would not allow conclusive statements about LISA being able to find a GW background due to the amount of parameter tuning required for an observable GW signal. In order to evaluate possible caveats of this statement we study the theoretical uncertainties related to the GW predictions in a two-fold approach using both state-of-the-art tools, BSMPT and TransitionListener, and also allow for model realizations in which the electroweak
symmetry is not restored in the high-temperature limit, which are the ones combining the loudest GW signals with the weakest
collider coverage.
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Earth and Planetary Astrophysics
WASP-12b Exhibits Persistent In-Transit H$\alpha$ Absorption
Shreyas Vissapragada, Fabienne Nail, Morgan MacLeod et al. (+6 more)
High-resolution H$\alpha$ and He 10830 Å transit spectroscopy can trace the extended upper atmospheres of
exoplanets, typically revealing excess in-transit absorption that occurs in the
planet's rest frame. However, hydrodynamical simulations predict that absorption should not strictly follow the
planet's orbital motion if gas quickly escapes the planetary Roche lobe and shears into
tidal tails. The ultra-hot Jupiter WASP-12b fills an exceptionally large fraction of its Roche lobe ($R_p/R_\mathrm{Roche} = 0.55$), and in this paper we present evidence for tidally-modulated
outflow kinematics on this unique
planet. We observed a transit of WASP-12b with MMT/Hectochelle and found an excess H$\alpha$ absorption of $3.29^{+0.35}_{-0.36}\%$ (9.3$\sigma$) during the transit and extending at least 30~min post-egress. The signal does not follow the
planet's orbital motion and instead appears largely in the
stellar rest frame, similar to the extended helium
outflows in HAT-P-32b and HAT-P-67b, and is slightly redshifted ($+5.4_{-1.7}^{+1.5}$ km s$^{-1}$). We demonstrate that a similar signal appears across previous high-sensitivity observations dating back to 2012 once the atypical signal kinematics and baseline self-subtraction are taken into account. Finally, we present a three-dimensional Athena++ model of WASP-12b's outflowing atmosphere that simultaneously exhibits the observed extended morphology and lack of
planet-aligned velocity gradient. Our study highlights the necessity of three-dimensional simulations for interpreting absorption lines formed in strong
outflows, where gas may not simply follow the
planet's Doppler signature.
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All authors Shreyas Vissapragada, Fabienne Nail, Morgan MacLeod, Adam Jensen, Stefan Czesla, Mercedes Lopez-Morales, Jea Adams Redai, Kevin N. Ortiz Ceballos, Jaehyon Rhee
High Energy Astrophysical Phenomena
Signatures of Compact Object Mergers Inside Stars in AGN Disks
Matteo Cantiello, Alexander J. Dittmann, Saavik Ford et al. (+4 more)
Disks of gas accreting onto supermassive black holes, powering active
galactic nuclei (AGN), can capture
stars from
nuclear star clusters or form
stars in situ via gravitational instability. The dense, hot disk environment can drive rapid
accretion onto embedded
stars, dramatically altering their
evolution. Models predict that, for sufficiently rapid
accretion, fresh gas replenishes hydrogen in
stellar cores as quickly as it is burned, and the
stars reach a quasi-steady state. Here we study encounters of such massive, long-lived (”immortal”)
stars with compact objects in AGN disks. We estimate the encounter rate and the timescale for a single compact remnant to spiral into an AGN
star; depending on how strongly feedback regulates the ensuing
accretion, the
star is either consumed in a collapsar-like, engine-driven transient or converted into a long-lived, quasi-
star-like object hosting a central black hole. We then study the merger of a binary black hole (BBH) inside the AGN
star, and show that gas drag hardens the binary to merger far faster than gravitational-wave emission alone. The resulting merger is a loud LIGO-Virgo-KAGRA (LVK) source, but the characteristic imprint of the dense environment -a strong suppression and dephasing of the inspiral relative to
vacuum- falls in the deci-Hz band rather than the milli-Hz LISA band, and is best resolved by next-generation detectors such as DECIGO. We estimate that this channel could contribute a BBH merger rate of up to $\sim8\,{\rm Gpc^{-3}\,yr^{-1}}$ in favorable scenarios, and discuss the model uncertainties and directions for future work.
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All authors Matteo Cantiello, Alexander J. Dittmann, Saavik Ford, Barry McKernan, Carlos Palenzuela, Rosalba Perna, Taeho Ryu
High Energy Physics (Theory)
Wilsonian Cosmology: de Sitter (in)Stability
Jean Alexandre, Lucien Heurtier and Silvia Pla
We develop a (Wilsonian) functional-renormalisation-group framework for scalar cosmology in which
quantum fluctuations of a scalar field are coarse-grained on cosmological spacelike hypersurfaces. Integrating out
quantum fluctuations with wavelengths smaller than the Hubble radius $H(t)^{-1}$, we obtain an effective scalar potential $U(\phi(t),H(t))$ that evolves in time. We derive a non-perturbative flow equation for this potential, together with the coupled set of (modified) Friedmann equations. We then apply this formalism to the simplest possible case of a de Sitter
vacuum when the scalar field is at rest, in two situations which satisfy exactly our flow equation: $(i)$ A flat potential, for which we find that the only pure de Sitter solution is unstable and corresponds to a saddle point. $(ii)$ A quadratic potential with
curvature $m^2>0$, for which we find that the presence of the mass term stabilises the system. The latter case leads to a de Sitter attractor either at the Hubble scale when the mass is larger than the Hubble scale at initial time, or by introducing a new attractor located at $H=m$ in the case the mass is smaller, which may be particularly relevant to the phenomenological study of dark energy and inflation theories.
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Strongly Correlated Electrons
Large scale theoretical investigation of the phase diagram of twisted bilayer MoTe$_2$ at fractional fillings: agreements and contradictions with current experiments
Heqiu Li, Jiabin Yu, Xiaodong Xu et al. (+2 more)
We present a comprehensive exact-diagonalization study of interaction-driven phases in twisted
bilayer MoTe$_2$ across experimentally relevant twist angles ($2.13^\circ$–$4^\circ$) and hole fillings. Using continuum-model moiré bands, we compare the one-band-per-valley (1BPV) projection with a two-band-per-valley (2BPV) calculation that includes interaction-driven band mixing, and we
benchmark both the widely used first-harmonic continuum model and a parameter-free DFT “fitting-free” model. At odd-denominator fillings, the 2BPV calculation reproduces the experimentally observed hierarchy of fractional Chern
insulators (FCIs) around $\theta\approx 3.7^\circ$, including robust incompressible states at $\nu=-2/3$, $-3/5$, and $-4/7$ while correctly finding the absence of an FCI at $\nu=-3/7$, and it favors a charge density wave ground state at $\nu=-1/3$ over the FCI. At half filling $\nu=-1/2$, the 1BPV calculation exhibits clear composite
Fermi liquid (CFL) signatures, whereas the band mixing in 2BPV calculations destabilizes the CFL ground state. Finally, motivated by the Landau-level analogy at $\theta\approx 2.13^\circ$, we test the proposed non-abelian Pfaffian state at $\nu=-3/2$ in the fully-polarized
spin sector but find no evidence for this state within the models and parameters studied. Our results establish a unified numerical
benchmark for correlated and topological phases in twisted
bilayer MoTe$_2$ and clarify where multi-band physics is essential for a quantitative comparison with experiments.
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All authors Heqiu Li, Jiabin Yu, Xiaodong Xu, B. Andrei Bernevig, N. Regnault
High Energy Physics (Theory)
Non-perturbative news from the conformal window
Álvaro Pastor-Gutiérrez
Dynamical
symmetry breaking plays a crucial role in mass and scale generation. In QCD-like theories, its dependence on the number of
fermion flavours determines the phase structure and the transition to the conformal regime. In this work, we compute non-perturbative corrections relevant to this phenomenom, including momentum dependencies and field invariants essential for an adequate realisation of the global
symmetries, by means of the functional renormalisation group and the generalised flow equation. We find that the critical gauge coupling required for dynamical
chiral symmetry breaking acquires a strong dependence on the number of flavours and increases sharply at $N_f^\textrm{crit}\simeq 7.30$ for $N_c=3$. This establishes a new picture of the phase transition to the conformal window that disfavours Miransky/BKT scaling and walking regimes but supports a first-order
quantum phase transition and a critical region with exotic dynamics and symmetric
fermion mass gaps.
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Astrophysics of Galaxies
A simulation-based quality-control framework for the broad-line region radius-luminosity relation
Juri Wladimir Seib, Francisco Pozo Nuñez and Sarah Elena Ivana Bosman
The broad-line region (BLR) radius-luminosity (R-L) relation underpins single-epoch black hole mass estimates in active
galactic nuclei (AGN). The published H\beta sample is heterogeneous in observational quality, and it remains unclear how much of its scatter is intrinsic rather than caused by systematics in lag recovery. We quantify the contribution of unreliable lag recovery to the observed scatter of the H\beta R-L relation and provide tools for quality control. We compile a publicly available database of reverberation mapping measurements for ~1200 AGN from 32 campaigns spanning more than three decades, including lags, luminosities, line widths, black hole masses, and observational metadata. We develop a simulation-based consistency framework in which damped random walk light curves are sampled according to each campaign's baseline, cadence, and signal-to-noise ratio, and lags are recovered with the interpolated cross-correlation function (ICCF). Comparing expected, reported, and simulation-retrieved lags defines a four-tier flagging scheme. We refit the R-L relation with UltraNest for progressively cleaner samples and construct consensus samples across three reference slopes to reduce model dependence. Of 248 H\beta sources, ~40% show discrepancies between reported and simulation-retrieved lags, while ~5% show direct inconsistencies between expected and retrieved lags. Excluding flagged sources and correcting for model bias reduces the inferred intrinsic scatter from \sigma = 0.26^{+0.02}_{-0.01} dex to 0.11\pm0.01 dex, with a corrected slope of \alpha = 0.48\pm0.02. Our results indicate that a substantial fraction of the observed H\beta R-L scatter arises from observational limitations and lag-recovery biases rather than intrinsic AGN diversity. The database, simulation code, and RM-Scout campaign-planning tool are publicly available.
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Astrophysics of Galaxies
Spin inference with the Black Hole Explorer. I. Fisher information matrix forecast
Joseph R. Farah, Daniel C. M. Palumbo, Michael D. Johnson et al. (+1 more)
General relativity predicts the presence of a thin, bright ring of light superimposed on the image of a black hole (the “
photon ring”), whose geometry is sensitive to the
spin of the black hole. Detecting this
photon ring in observations of
nuclear supermassive black holes would yield insight into
gravity in the strong-field regime as well as their growth histories. The Black Hole Explorer (BHEX) is a mission being developed to detect the
photon ring for the first time, raising the question of how precisely we can constrain
spin from its observations. We use the method of Fisher information
matrices (FIMs) along with a simple dual-cone semi-analytic emission model to forecast BHEX
spin posterior widths for the primary science targets (M87* and Sgr~A*) in a variety of configurations. We find that BHEX can constrain the dimensionless
spin of its targets to a precision of $\sigma_{a_*} \ll 0.1$ after 30 orbits, even in the presence of significant systematic errors. We validate our results via numerical checks for stability and robustness, as well as synthetic data cross-validation to assess handling of covariances and prior information in the FIM against a full posterior exploration.
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All authors Joseph R. Farah, Daniel C. M. Palumbo, Michael D. Johnson, Dominic O. Chang
Astrophysics of Galaxies
More Numerous and Bluer: Companions of the Brightest Little Red Dots Differ from Control Galaxies at $>3\sigma$, Hinting at Synchronized Black Hole Seed Formation
Fabio Pacucci and C. Megan Urry
The Little Red Dots (LRDs) are compact, red sources at $4 \lesssim z \lesssim 9$, likely powered by accreting massive black holes. Multiple studies have detected blue companions in their vicinity: we compare $253$ LRDs, uniformly selected across several JWST deep fields, against $>7000$ matched controls in the same mosaics. We find that $27.7\%$ of the brightest LRD quartile (in F444W) hosts a blue ($\beta<-1$) companion at $0.5-2$ kpc, versus $11.6\%$ of
redshift-matched controls: a $\times 2.39$ excess, significant at $3.3\sigma$. Against controls additionally matched in brightness and compactness, the excess ratio is similar ($\times 2.17$), although constrained only at $1.4\sigma$ by the small size of that control pool. This phenomenon is limited to the brightest LRDs, as the full LRD sample pairs at a rate indistinguishable from controls. Moreover, the excess is confined to the close-pair window ($< 2$ kpc), outside which LRD environments are ordinary. Their companions are overwhelmingly ($92\%$) blue and significantly bluer than those of controls ($\beta\approx-2.32$ versus $-1.92$), rejecting a common parent distribution at $3.4\sigma$. The signal is thus directional in brightness, separation, and companion color, as expected for synchronized-pair seed formation. Therefore, we conclude that the association between the brightest LRDs and their close blue companions is physical, i.e., the two phenomena are causally connected: either one drives the other, or both emerge from the same synchronized formation event. A natural explanation is that the radiation from these young,
star-forming neighbors enabled the direct collapse of the massive black holes powering the LRDs themselves.
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Quantum Physics
Single-shot online sequence classification with unbounded quantum memory advantage
Keith K. Ng, Haochen Jay Li, Mile Gu et al. (+1 more)
An
agent monitors a complex environment, receiving one observation at each time step and eventually deciding how to label the resulting sequence. Does the sequence indicate an anomaly, and if so, of what type? Does it signal
market instability, and to what degree? This is the setting of online multi-class classification: the input arrives sequentially, the full history is never available at once, and the
agent must retain any past information relevant to the eventual decision. As the environment becomes more complex, the
memory needed to track this information can grow rapidly without bound. Here, we introduce families of such multi-class classification games and show that any exact classical
agent requires
memory that grows without bound, whereas exact
quantum agents can solve all tasks in the family with bounded
memory. This separation is sharp: any classical
agent using less than the required
memory, under suitable input distributions, performs arbitrarily close to random guessing. Moreover, our
quantum constructions are provably
memory minimal, allowing us to derive the exact classical and
quantum memory complexities to perform such tasks. In doing so, we establish an unbounded separation between classical and
quantum memory cost for online multi-class classification.
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All authors Keith K. Ng, Haochen Jay Li, Mile Gu, Jayne Thompson
Instrumentation and Methods for Astrophysics
BlueBird 6 is Fainter than Block 1 Satellites
Anthony Mallama and Richard E. Cole
The mean apparent magnitude for BlueBird 6, the first Block 2 satellite of the BlueBird constellation, is 3.85 +/- 0.10 while that for Block 1 spacecraft is 3.30 +/- 0.07. So, BlueBird 6 is 0.55 magnitudes fainter. Likewise, the means of apparent magnitudes adjusted to a uniform distance of 1,000 km are 4.32 +/- 0.08 and 3.77 +/- 0.06, respectively. This difference is also 0.55 magnitude. The dimming is unexpected because the Block 2 satellites are ~3.5 times as large as Block 1. BlueBird 6 is only 17% as bright as Block 1 spacecraft per unit surface area. Possible explanations are discussed. All BlueBird satellites exceed the brightness limits recommended by the International Astronomical Union. However, they will be fewer in number than other satellite constellations.
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Mathematical Physics
A Comment on Local Hypercube Inequalities
Keyou Zhuo, Tian-Shun Chen and Kilar Zhang
This comment gives dimension-independent analytic proofs of the local inequalities arising in the odd- and even-dimensional constructions of higher-dimensional partition charge functions. The prior works established these inequalities by exhaustive computation in low dimensions and tested them numerically in selected higher dimensions.
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Solar and Stellar Astrophysics
Solar-Cycle Variation of Newly Emerging Coronal Holes during Solar Cycle 24
Akash Vinod Shirke and Khagendra Katuwal
Coronal holes (CHs) are regions of predominantly open
magnetic field and important sources of high-speed
solar wind streams. We present a manually compiled catalogue of newly emerging CHs during
Solar Cycle 24 (2010-2019), identified from daily CHIMERA maps provided by SolarMonitor. Unlike existing area-based catalogues, our
dataset tracks the daily emergence of new CHs in northern, southern, and equatorial latitude zones. The emergence rate of equatorial CHs is anti-correlated with the International Sunspot Number (Pearson r = -0.523, p = 6.2 x 10^-9), indicating reduced formation of low-latitude CHs near
solar maximum. The hemispheric asymmetry of CH emergence is also anti-correlated with the hemispheric asymmetry of sunspot activity (r = -0.461, p = 5.2 x 10^-7), suggesting that new CHs preferentially emerge in the hemisphere with lower sunspot activity. The total CH emergence rate is lowest near
solar maximum and highest during the declining phase. These results provide new observational constraints on the
evolution of open
magnetic flux over the
solar cycle.
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Earth and Planetary Astrophysics
CHIANTE I: Obliquity Measurements of Four High-Priority Ariel Targets in Binaries
Alex S. Polanski, Malena Rice, Catherine A. Clark et al. (+10 more)
We present the first results from CHIANTE: a program using the EXtreme PREcision Spectrograph (EXPRES) at the Lowell Discovery
Telescope to characterize potential targets of the Ariel mission, anticipated to launch in 2031. We report Rossiter-McLaughlin measurements of four Ariel tier 3 hot-Jupiters which reside in binary
star systems: KELT-2 Ab, KELT-3 Ab, TOI-1333 Ab, and TOI-1789 Ab. Joint modeling of EXPRES and archival radial velocities with photometry from TESS finds all four
planets to be aligned their host
stars, despite the host
stars spanning the $T_{\text{eff}}$ realignment break, which has been found to divide the
planets in multi-
star systems into two subsets: those around cool
stars that are preferentially aligned, and those around hot
stars that exhibit
stellar obliquities consistent with isotropy. We revise the $T_{\text{eff}}$ realignment break to be $=6193\pm103$ K, consistent with, but hotter than, previous work. We compare the observed
stellar obliquity distribution for all multi-
star, hot-Jupiter hosts above this boundary to an expected distribution produced via
stellar von-Zeipel-Kozai-Lidov (ZKL) oscillations, a mechanism often invoked to explain misaligned
planets in multi-
star systems. A simple population synthesis model finds that a pure ZKL population is unable to replicate the observed obliquities. In particular, both the number of aligned and near-polar systems we see today are underestimated. However, adding contributions from aligned and
planet-
planet scattering populations alongside ZKL oscillations better describes the observed distribution. Nonetheless, more obliquity measurements for
planets in multi-
star systems are needed to better discern the contributions of each mechanism the observed
stellar obliquity distribution.
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All authors Alex S. Polanski, Malena Rice, Catherine A. Clark, Rachael M. Roettenbacher, Lily L. Zhao, John M. Brewer, Momo Ellwarth, Emily A. Gilbert, Joe Llama, Andrew W. Mayo, Andrew E. Szymkowiak, Gerard T. van Belle, Olivia Weiss
General Relativity and Quantum Cosmology
Brans Dicke scalar-tensor gravity and unimodular FRW cosmology with Coleman-Weinberg potential
Manda Malekpour and Hossein Ghaffarnejad
As alternative
gravity theories with respect to the general relativity, the Brans-Dicke (BD) scalar tensor model is well known for which the BD parameter is controller the best fit observational data and so its cosmological model is studied in the literature well. On the other side, the Coleman Weinberg (CW) self-interaction scalar field potential coming from radiation corrections of Feynman diagrams is used to describe the best fit
cosmic inflation phase and reheating phase. This has a logarithmic term with respect to the
Higgs potential and it is applicable even for massless
bosons. From particle physics point of view, this is used usually to describe the
Higgs mechanism and creation of massive Goldstone
bosons. As a basic model to describe the
cosmic inflation the cosmological constant is used to describe the de Sitter space where the cosmological constant play as dark energy density. Since, the cosmological constant is a hierarchy problem and it is added in the Einstein equation without to describe that where that is come originally? at a first time the Albert Einstein himself proposed a uni-modular frame for which the cosmological constant generate from a integral constant. This idea is very well because it resolve `fine tuning` problem of the cosmological constant parameter. Hence we use this idea for the BD theory in presence of the CW potential and obtained suitable solutions of the field equations for a flat Robertson-Walker space time by regarding the slow roll parameters of
cosmic inflation and then we find the best fit correspondence between the theoretical predictions of the parameters of the solutions and the Planck2018, DESI2024, and ACT2025 observational data.
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High Energy Physics (Phenomenology)
Operational quantum estimation theory for neutrino oscillations: identifiability, attainability, and spectral precision bounds
Jianlong Lu
Quantum Fisher information (QFI) bounds state-encoded precision before measurement choice but does not establish identifiability, joint attainability, or detector sensitivity. We develop an operational framework for three-
flavor oscillations that separates state, measurement, and reconstructed-event information. At fixed baseline, energy, source
flavor, and matter profile, the propagated state is a pure qutrit, so its six-coordinate QFI has rank at most four. Resolved broadband components can restore rank because the aggregate kernel equals the intersection of their active kernels. We analyze joint attainability using
quantum curvature, exact pure-state Holevo costs, and numerical primal-dual brackets, and propagate information through
flavor projection, detector response, Poisson sampling, and nuisance profiling. An independent implementation of the public DUNE GLoBES configuration reproduces the reference spectra to relative error $3.87\times10^{-16}$ and the profiled likelihood
curvature to $3.26\times10^{-6}$. Under the declared scaling and tolerance, its 264-bin event information has numerical rank six at all 176 documented physics points, whereas any four retained rule totals have rank at most four. The weakest record has effective rank five at the declared practical threshold. A conditional likelihood pilot also shows finite-grid overcoverage and dependence on the auxiliary-measurement ensemble. The framework identifies when local
quantum or Fisher bounds do not support global experimental-sensitivity claims.
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Biological Physics · Cross-listed from eess.SP
Physics-Constrained Deep Learning Model for Contactless Blood Pressure Monitoring from Triaxial Bodyseismography
Yuanyuan Zhang, Yida Zhang, Jiahui Li et al. (+6 more)
Ballistocardiography (BCG) is promising for unobtrusive long-term blood pressure (BP) monitoring in laboratory settings, but traditional BCG signals are vulnerable to the variations in body-bed interaction with shifted fiducial points in temporal or amplitude axis, and BP varies with personal hemodynamic changes, causing misaligned representations that affect model generalizability and robustness. In this work, we propose Phy-BP, a physics-constrained BP estimation framework based on triaxial bodyseismography (BSG) acquired using bed-mounted sensors as an extension of single-axis BCG. Firstly, we design an adaptive quality-control
algorithm combining neighboring beat patterns and universal cardiogenic templates to retain reliable cardiac components. Secondly, we propose a physical model of wave propagation through the body-bed system to constrain latent feature
evolution, aligning triaxial representations generated by a shared cardiogenic excitation. These mechanical constraints connect multi-axis feature learning to body-bed dynamics and complement data-driven regression from vibration signals. Evaluation on a 162-hour hospital
dataset from 21 subjects against invasive arterial BP yields a mean absolute error of 5.07 mmHg, a prediction-error standard deviation of 7.24 mmHg, and a Pearson correlation coefficient of 0.86 for mean arterial pressure. This framework is intended for unobtrusive monitoring during rest and sleep, with potential applications in overnight hospital and home monitoring.
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All authors Yuanyuan Zhang, Yida Zhang, Jiahui Li, Yuyan Wu, Fei Dou, Xiao Yin, Zhenlin An, Hae Young Noh, Wenzhan Song
Strongly Correlated Electrons
Flux-induced Aharonov-Bohm Oscillation in the Tunneling Spectroscopy of Kitaev Spin Liquids
Wen-Han Kao and Elio J. König
Identifying emergent flux excitations and signatures of their mutual statistics with itinerant Majorana
fermions remains a central challenge in Kitaev
spin liquids. We show that an isolated $\pi$ flux imprints an intrinsic Aharonov-Bohm-like interference pattern on the charge-neutral Majorana continuum. Spatially resolved scanning tunneling microscopy with inelastic electron tunneling spectroscopy (STM-IETS) probes this oscillation in the local dynamical
spin response as a function of both bias voltage and tip-flux separation, reflecting the $\pi$ phase acquired by Majorana trajectories encircling the flux. We show that large-scale exact diagonalization of the Kitaev honeycomb model and a complementary low-energy continuum theory yield consistent radial oscillations. These results provide a finite-energy, spatially resolved tunneling signature of a preexisting flux and a diagnostic of
fermion-flux mutual statistics without requiring manipulation of individual anyons in the Kitaev
spin liquid.
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Quantum Gases
Spinor condensate persistent currents in an atomtronic Josephson necklace
Sayan Chatterjee, Nalinikanta Pradhan, Rina Kanamoto et al. (+2 more)
The investigation of superflow in multi-junction Josephson
circuits is currently a leading frontier of physics research, probing the fundamental manifestations of macroscopic phase coherence and enabling applications to
quantum simulation, metrology and computing. In this work, we extensively investigate the stability and dynamics of persistent currents of a spinor atomic Bose-Einstein condensate on a ring with multiple Josephson junctions. Specifically, we examine the effects of positive and negative interspecies interactions, co- and counter-rotation, population and Manakov asymmetry, as well as Rabi coupling on the persistent currents carried by the two components. Our analysis reveals that the presence of a second species offers multiple mechanisms for unprecedented manipulation of supercurrents on the ring, including phase-slip engineering, stability control, current-inversion switching and supercurrent pumping. Our study provides a roadmap for the engineering of persistent currents in binary ring condensates in necklace potentials, with significant implications for atomtronics, matter-wave interferometry and sensing using atomic Bose gases.
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All authors Sayan Chatterjee, Nalinikanta Pradhan, Rina Kanamoto, M. Bhattacharya, Pankaj Kumar Mishra
Astrophysics of Galaxies
The descendants of $z \gtrsim 10$ JWST galaxies in the COLIBRE simulations
Xu Zhao, Carlos S. Frenk, Andrew Pontzen et al. (+9 more)
Recent observations with JWST have revealed a population of UV-bright
galaxies at $z\gtrsim 10$. This discovery naturally raises the question: what do such early
galaxies evolve into by the present day? In this work, we address this descendant question using the new-generation COLIBRE cosmological hydrodynamical simulations to trace bright
galaxies selected at $z=10$ and follow their descendants to the present day. Most of the high-
redshift galaxies do not survive as distinct, self-bound objects to $z=0$; instead, the majority are incorporated into more massive systems through merging or disruption. The surviving descendants span a broad range of present-day
stellar masses, although they are most commonly intermediate- to high-mass, $M_\star\sim10^{10}$–$10^{11} M_\odot$. They typically reside in
galaxy groups and clusters, with host
halo masses, $M_{200c}\sim10^{13}$–$10^{14} M_\odot$. The large scatter in descendant
stellar mass shows that present-day outcomes retain only a weak
memory of the
stellar mass of the high-
redshift progenitor. We show that the
evolution of descendant host
halo masses is consistent with the forward conditional distribution predicted by extended Press–Schechter (EPS) theory, both in the median growth and in the large scatter in descendant mass. In particular, EPS confirms that massive present-day
galaxies typically do not originate from the most massive objects at high
redshift. A
galaxy observed at $z\gtrsim10$ therefore cannot be interpreted as the direct progenitor of a single class of $z=0$
galaxies.
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All authors Xu Zhao, Carlos S. Frenk, Andrew Pontzen, Kyle A. Oman, Evgenii Chaikin, Isabel Santos-Santos, Shengdong Lu, Joop Schaye, Alejandro Benítez-Llambay, Filip Huško, Alexander J. Richings, Matthieu Schaller
Quantum Physics
Dissipation-induced Sachdev-Ye-Kitaev physics in many-body cavity quantum electrodynamics
Pietro Pacchioni, Filippo Ferrari, Vincenzo Savona et al. (+1 more)
We show that cavity
quantum electrodynamics (QED) devices can realize dissipative Sachdev-Ye-Kitaev (SYK) universality, a paradigmatic setting for
quantum chaos in open many-body systems. Ultracold
fermions with disordered, all-to-all cavity-mediated interactions provide two complementary routes: atomic spontaneous emission in a single-mode cavity and
photon leakage from a multimode cavity. Strikingly, both converge to the same non-Hermitian random-
matrix universality despite originating from integrable and chaotic closed-system limits, respectively. In the single-mode cavity, dissipation creates
quantum chaos from an integrable
Hamiltonian. We trace this convergence to a tunable growth in dissipative rank, controlled, respectively, by the Lamb-Dicke parameter and the cavity-mode spacing. The integrability-to-chaos crossover is accompanied by a dynamical crossover from long-lived prethermal
memory to rapid thermalization, visible in single-atom-resolved densities.
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All authors Pietro Pacchioni, Filippo Ferrari, Vincenzo Savona, Matteo Seclì