Mathematical Physics
The $\mathbb{Z}_2$-Index of a Pair of Pure States and the Topology of Interacting 1D Superconductors
Anna Mazhar and Jacob Shapiro
We define a relative $\mathbb{Z}_2$-index $\mathcal{N}(\omega_1,\omega_2)$ for locally-comparable, parity-invariant pure states on a unital $C^*$-
algebra. We prove that the index is well-defined, multiplicative, invariant under parity-preserving
automorphisms, and locally constant in the norm
topology. For the one-dimensional self-dual CAR
algebra, we apply this construction to the half-chain
automorphism $\sigma$ and define the many-body Majorana number $\mathcal{N}\sigma(\omega):=\mathcal{N}(\omega,\omega\circ\sigma)$ for parity-invariant $\sigma$-local pure states. In the quasi-free
Hilbert–Schmidt regime, this index agrees with the usual single-body Majorana number. We then introduce symmetric local
automorphism paths and prove that $\mathcal{N}_\sigma$ completely classifies the resulting automorphic-path-components. This automorphic-path equivalence retains the bulk Majorana number but may forget a relative zero-dimensional parity obstruction.
Read the full abstract ▾
General Relativity and Quantum Cosmology
Acceleration and Rotation in Three Dimensions
Cameron R D Bunney, Ruth Gregory and Robert B Mann
We present a new family of exact solutions representing accelerating, rotating, point particle and black hole solutions in three-dimensional Einstein
gravity. We investigate their
geometric properties and the global
embedding in three dimensional anti-de Sitter space. Our results extend the catalogue of exact solutions in three-dimensional Einstein
gravity and provide a useful setting for the study of black hole thermodynamics, asymptotic
symmetries, and holography.
Read the full abstract ▾
High Energy Physics (Phenomenology)
Constrained functional priors for Bayesian inference of hot QCD matter
G. Guimarães, L. Perin and M. Luzum
Bayesian analyses of heavy-ion collisions rely on functional inputs, such as temperature-dependent transport coefficients and the equation of state, whose prior specification remains a significant source of uncertainty. Standard approaches employ low-dimensional parametrizations that can impose artificial correlations and leave the resulting inference sensitive to the assumed functional form. We develop a nonparametric framework for constructing priors over such functions using Gaussian processes, tailored to emulator-based inference in heavy-ion phenomenology. Truncated Karhunen–Loève expansions yield optimized finite-dimensional representations suitable for use as emulator inputs. We investigate how physical constraints can be incorporated into these priors, demonstrating that rejection-based methods produce non-Gaussian measures and induce nontrivial correlations in the expansion coefficients. By contrast, pushforward constructions enforce the constraints while preserving a tractable Gaussian measure in a latent space. These results provide a systematic framework for incorporating physical constraints into functional priors and clarify their effects on the statistical structure of the finite-dimensional representations used in
Bayesian inference.
Read the full abstract ▾
Cosmology and Nongalactic Astrophysics
Reconstructing stochastic gravitational-wave signals from flavour deconstruction with LISA
Noemi Fabri, Raphael Bertrand-Delgado, Danny Laghi et al. (+1 more)
We investigate the reconstruction of a
stochastic gravitational-wave background generated by a first-order phase transition in flavour-deconstruction models using the
Laser Interferometer Space
Antenna (LISA). In these scenarios, the spontaneous breaking of an extended flavour-non-universal gauge
symmetry at the TeV scale can both generate the observed hierarchies of Standard Model
fermion masses and mixing angles and induce a strong first-order phase transition. We consider representative
benchmark points of the model, compute the corresponding thermodynamic transition parameters, and construct the resulting gravitational-wave spectra using a state-of-the-art sound-wave template. We then inject these spectra into simulated LISA data and perform
Bayesian inference with SGWBinner, jointly reconstructing the cosmological signal, instrumental noise, and astrophysical foregrounds. We find that the strongest
benchmark signal can be successfully reconstructed, whereas weaker signals are substantially degenerate with the unresolved extragalactic compact-binary foreground. We further show that tighter prior information on this foreground, motivated by observations with ground-based detectors, can reduce this degeneracy and improve signal reconstruction. Our results demonstrate that flavour-deconstruction models can produce signals accessible to LISA, while highlighting the importance of astrophysical-foreground modelling for their identification and characterization.
Read the full abstract ▾
All authors Noemi Fabri, Raphael Bertrand-Delgado, Danny Laghi, Lucio Mayer
Optics
Intracavity Dual-Resonance Stimulated Raman Spectroscopy with Cavity Ringdown Readout for Resolving Hydrogen Rotational Raman Transitions
Qinxue Nie, Guanda Lyu, Yue Yan et al. (+1 more)
Gas-phase rotational Raman lineshape metrology of hydrogen (H2) is challenging due to its weak Raman scattering cross-sections and intrinsically narrow linewidths. We report the first measurement of the complete Dicke-narrowing
evolution of the H2 rotational Raman transitions S0(1) and S0(0), enabled by intracavity dual-resonance stimulated Raman spectroscopy with cavity ringdown readout and kHz-level spectral resolution. Our results establish a
benchmark for gas-phase Raman lineshape measurements and provide stringent constraints for regime-based pressure-dependent linewidth models.
Read the full abstract ▾
All authors Qinxue Nie, Guanda Lyu, Yue Yan, Wei Ren
Earth and Planetary Astrophysics
Probing the Taxonomic Diversity of the Small Near-Earth Object Population
Andy J. López-Oquendo, David E. Trilling, Michael Mommert et al. (+1 more)
Small near-Earth objects (NEOs) represent the immediate source population of meteors and meteorites and provide a direct window into the compositional and dynamical
evolution of the inner
Solar System. However, their small sizes, rapid rotation rates, and short observability windows have historically limited systematic compositional characterization. We present results from a multi-year rapid-response near-infrared spectrophotometric survey of recently discovered NEOs conducted with the UKIRT-WFCAM instrument between 2016 and 2024. Our campaign obtained 371 observation sequences, yielding reliable color measurements and probabilistic taxonomic classifications for 122 NEOs, with diameters ranging from 5 m to 150 m and a median size of 60 m. We employed lightcurve-corrected Z, J, H, and K photometry and a machine-learning-based classification framework to derive both observed and debiased taxonomic distributions as a function of object size. The observed taxonomic fractions show a population of small NEOs dominated by S-complex and CX-complex objects in nearly equal proportions. After accounting for observational selection biases, however, the inferred intrinsic population is instead dominated by dark, carbonaceous (CX-complex) bodies, with important implications for the intrinsic composition of the small NEO population. We further explore the relationship between small NEOs, meteorite fall statistics, and atmospheric filtering effects, finding that a substantial fraction of carbonaceous material likely does not survive atmospheric entry. These results highlight the importance of debiased surveys of small NEOs for interpreting the meteorite record, refining delivery models from the main belt, and informing the selection of future mission targets and planetary defense strategies.
Read the full abstract ▾
All authors Andy J. López-Oquendo, David E. Trilling, Michael Mommert, Michaël Marsset
Astrophysics of Galaxies
V. A. Fawcett, C. M. Harrison, T. Costa et al. (+8 more)
Feedback from dusty
quasars is thought to be a key driver in
galaxy evolution. Multiple studies have reported a link between
dust extinction and
radio emission in
quasars, possibly attributed to winds or jets interacting with the interstellar medium. We use optical spectra from the Dark Energy Spectroscopic Instrument (DESI) to test whether ionised
outflows could be driving the observed
radio-
dust connection and to determine whether
dust and/or colour play a role in producing high-velocity ionised
outflows in
quasars. Based on a sample of 3418 DESI
quasars at 0.5 < z < 0.9, we constrained the [OIII]$\lambda$5007 kinematics by fitting the spectra with PyQSOFit and comparing the observed trends among the [OIII]
outflow velocity and the line-of-sight
dust extinction E(B-V), optical-to-mid-infrared (MIR) colour g-W2, and L6$\mu$m/L5100A (a proxy for MIR excess). Utilising
radio data from the LOFAR Two-metre Sky Survey (LoTSS) DR2, we also explored the link between
radio,
dust, and
outflows. We find that the link between
radio emission and
dust obscuration is driven by sources hosting high-velocity ionised
outflows. However, we find no significant trend between the [OIII]
outflow velocity and E(B-V), which suggests
dust extinction alone is not a significant factor in determining whether a
quasar hosts a powerful ionised
outflow. On the other hand, we find a clear positive trend between g-W2 and
outflow velocity, even after controlling for luminosity. We suggest this is due to a connection between a MIR excess (boosting the W2 band) and
outflows, which is supported by a positive trend between L6$\mu$m/L5100A and
outflow velocity. Our results point to a scenario in which
outflows shock the surrounding
dust and gas, heating the
dust and boosting both the MIR and
radio emission.
Read the full abstract ▾
All authors V. A. Fawcett, C. M. Harrison, T. Costa, D. M. Alexander, C. Andonie, H. Haidar, R. D. Shepherd, C. L. Sargent, M. J. Temple, C. Circosta, D. J. Rosario
Plasma Physics
Enhanced Extreme Ultraviolet Emission from Laser-heated Blow-Off Tin Plasmas
Mathew P. Polek, Towfiq Ahmed, Kiran Linsuain et al. (+4 more)
This work investigates extreme ultraviolet (EUV) emission at 13.5 nm from
laser produced tin
plasmas generated using a mass limited
laser blow off (LBO) plume.
Read the full abstract ▾
All authors Mathew P. Polek, Towfiq Ahmed, Kiran Linsuain, Tyler E. Ray, Igor Golovkin, Farhat N. Beg, Sivanandan S. Harilal
Cosmology and Nongalactic Astrophysics
Comment on `Measuring the Hubble Constant Using Strongly Lensed Gravitational Wave Signals'
Jason S.C. Poon and Otto A. Hannuksela
In Huang et al (JCAP08(2023)003), the work claimed that the Hubble constant can be constrained from lensed gravitational waves, despite the absence of information on GW source
redshift or Einstein radius (angular size of the lens), as long as lens
redshift is provided independently. To demonstrate, the authors set up a singular isothermal sphere lens model and applied Fisher information
matrix and
Bayesian parameter estimation on injected lensed GWs. However, their conclusion contradicts our previous work on degeneracies of GW lens system parameters. In this comment, we illustrate that Hubble constant cannot be measured with lens
redshift alone, in the absence of source
redshift or (Einstein radius).
Read the full abstract ▾
Physics Education
Stable levitation of ring magnets: A low-cost, 3D-printed experiment on the magnetic force-distance law
M. Flores, A. Kahrs, F. Rinderknecht et al. (+1 more)
Magnetic levitation is one of the most captivating phenomena in physics, combining a striking visual appeal with the rich underlying physics of forces and interactions in
equilibrium. Bringing it into undergraduate laboratories in a quantitative way is nevertheless often hindered by the intrinsic instability of static
magnetic systems and by the high cost of active control systems. Here we present a simple, safe, and very low-cost experiment that uses ring-shaped ferrite magnets together with a mechanical stabilization system fabricated by 3D printing in a male–female configuration. The apparatus lets undergraduate students explore directly and quantitatively the relationship between the magnitude of the
magnetic force and the separation distance. We assess the robustness of the device through experimental tests, whose results show excellent quantitative agreement with the equivalent current-loop model. Furthermore, we validate this model through a complementary, independent first-principles-based methodology based on axial
magnetic field profiling. To support reproducibility, the 3D design files are made available in a public, open-access repository.
Read the full abstract ▾
All authors M. Flores, A. Kahrs, F. Rinderknecht, Arturo C. Martí
Plasma Physics
ELMO: An Uncertainty-Aware Simulation-to-Surrogate Workflow for Fast Pedestal Linear-Stability Prediction
Nami Li, X. Q. Xu, T. Osborne et al. (+5 more)
Rapid prediction of pedestal linear stability is important for exploring tokamak operating space, uncertainty quantification, and future model-informed control, but mode-resolved magnetohydrodynamic stability calculations using BOUT++ are computationally expensive. We present a focused implementation of ELMO–the Edge Learning and Modeling Orchestrator–as an uncertainty-aware simulation-to-surrogate workflow integrating
equilibrium generation, field-aligned mesh construction, large-scale BOUT++ calculations, automated campaign execution and data reduction, and Gaussian Process Regression (GPR). For a single DIII-D
plasma shape, 3,869 of 7,992 requested configurations completed
equilibrium reconstruction, mesh generation, stability calculation, and quality control. Each retained
equilibrium was evaluated at sixteen toroidal mode numbers, $n=5$–80 with $\Delta n=5$, using ideal-MHD and ideal-plus-diamagnetic models, producing 123,808 mode-resolved calculations. Using eight pedestal features, the GPR surrogate predicts two sixteen-mode growth-rate spectra with latent posterior uncertainty estimates. Across five independent test realizations, the maximum-growth-rate prediction achieved $R^2=0.978\pm0.013$ for ideal MHD and $R^2=0.966\pm0.009$ for ideal-plus-diamagnetic physics. The surrogate reproduces the spectral shape and dominant unstable mode. Calibration diagnostics indicate that posterior uncertainties are useful for relative acquisition but are underdispersed and should not be interpreted as calibrated prediction intervals. Prediction of all 32 outputs requires about 20 ms on one CPU core, compared with about 21 min using 128 CPU cores for the corresponding BOUT++ scan, giving a $6.3\times10^4$-fold wall-clock speedup and an $8.1\times10^6$-fold reduction in computational cost.
Read the full abstract ▾
All authors Nami Li, X. Q. Xu, T. Osborne, E. Suchyta, Y. C. Fu, N. Podhorszki, H. Wang, Z. Li
Fluid Dynamics
Droplet sizes from impulsive capillary jets: an exponential distribution with no lower cut-off
Alfonso M. Ganan-Calvo
A collapsing cavity throws up a ligament, which fragments into a train of droplets whose sizes are commonly given a lower bound at a fixed multiple of the viscocapillary length $\ell_\mu=\mu^2/\rho\sigma$. We show that no such bound exists, for a reason more general than the fate of one parameter: an impulsive jet possesses no length of its own. The similarity solutions that govern each pinch contain none, the cascade of stretching and iterated satellites introduces none, and $\ell_\mu$ belongs to the singularity rather than to the droplets. A size distribution built on such a process can inherit a scale from one place only, the cavity that launched the jet. Computations of bubble bursting, confined and unconfined, bear this out. The floor they display is the one the mesh imposes, not a property of the fluid, and wherever the mesh looks below $\ell_\mu$ it finds droplets. The census of unique emitted droplets is exponential, with a single scale set by the cavity radius, indifferent both to how vigorous the event is and to how much
liquid surrounds it. An exponential is the least structured census compatible with a prescribed mean, so the fragmentation keeps the size of the cavity and no other
memory of its parent. Sustained stretching does keep such a
memory, imprinting the corrugation of the parent thread and yielding the peaked, gamma-like distributions reported for ligament-mediated fragmentation. The manner of loading, and not the fluid alone, selects the shape of a spray.
Read the full abstract ▾
Materials Science
Benchtop Momentum-Resolved Phonon Spectroscopy: Unlocking Lattice Dynamics via X-ray Diffuse Scattering
Paulo H. V. da Silva, Tarsis M. Germano, Rafaela F. S. Penacchio et al. (+1 more)
Momentum-resolved
phonon spectroscopy is essential for understanding the thermal, electronic, and structural properties of materials, yet it traditionally necessitates access to large-scale synchrotron or
neutron facilities. We report a paradigm shift by demonstrating the accurate measurement and quantitative analysis of Thermal Diffuse Scattering (TDS) patterns using a commercially available benchtop Small/Wide-Angle X-ray Scattering (SAXS/WAXS) instrument. By utilizing a low-energy (8 keV) X-ray source and a custom-integrated
vacuum geometry, we acquired characteristic TDS patterns in silicon (111) and (100) slabs. We demonstrate that these benchtop images contain sufficient information to extract interatomic force constants (IFCs) through global optimization
algorithms, achieving a fitting accuracy comparable to those obtained from simulated data with statistical noise. Crucially, this capability provides access to
phonon information across the entire Brillouin Zone, a critical component of
lattice dynamics unavailable via standard laboratory techniques like first-order Raman spectroscopy. This low-barrier approach makes synchrotron-level
lattice dynamics characterization accessible to virtually any research laboratory, enabling new avenues for the study of intrinsic strain and anisotropic
lattice dynamics in emerging material systems.
Read the full abstract ▾
All authors Paulo H. V. da Silva, Tarsis M. Germano, Rafaela F. S. Penacchio, Sergio L. Morelhao
Cosmology and Nongalactic Astrophysics
Investigating the magnetic field in the inter-cluster filament between Abell 3667 and Abell 3651 with POSSUM
C. Stuardi, S. P. O'Sullivan, L. Rudnick et al. (+19 more)
[Abridged abstract] The objective of this study is to measure the
magnetic field within the prominent inter-cluster filament recently detected in X-rays by the extended ROentgen Survey with an Imaging
Telescope Array (eROSITA). This filament spans over 13 Mpc projected on the sky, connecting the
galaxy clusters Abell 3667 and Abell 3651. We employed the Polarisation Sky Survey of the Universe's Magnetism (POSSUM) Rotation Measure (RM) grid to isolate the RM dispersion and median value of background polarised sources induced by the filament's magnetised
plasma, and to infer the strength of this
magnetic field. The filament region is sampled by 54 background polarised sources. After subtracting the foreground
Galactic RM, we detected a marginal residual RM dispersion in the filament region of $6.9\pm3.6$ rad/m$^{2}$, together with a coherent residual RM signal with median $6.3\pm1.3$ rad/m$^{2}$. Assuming simplified single-scale
magnetic-field models and adopting informed priors on the thermal electron density distribution derived from the X-ray analysis, we constrained the
magnetic field strength to the range 0.1-3.5 $\mu$G within 95$\%$ confidence, with preferred values around 0.2-0.3 $\mu$G depending on the assumed
magnetic-field coherence scale. However, we also found that the
Galactic foreground RM in this region is highly structured on angular scales comparable to the extent of the filament itself, representing a major source of uncertainty for the RM analysis. Our results provide the first
magnetic field constraints based on Faraday rotation measurements in an individual X-ray-detected inter-cluster filament, with field strengths consistent with theoretical expectations for gas in bridges and cluster outskirts. Our analysis also highlights the critical importance of accurately modelling
Galactic RM foregrounds for future studies of extra-
galactic magnetism with POSSUM and the SKA.
Read the full abstract ▾
All authors C. Stuardi, S. P. O'Sullivan, L. Rudnick, G. Bernardi, A. Bonafede, J. Dietl, T. Akahori, D. Alonso-López, C. Anderson, E. Carretti, B. M. Gaensler, G. Heald, F. Loi, Y. K. Ma, E. Osinga, G. Pignataro, C. Riseley, X. Sun, A. Thomson, C. L. Van Eck, T. Vernstrom, J. L. West
High Energy Astrophysical Phenomena
Decisive evidence for a global cosmic-ray feature in gamma-ray data
Fernando Valenciano, Pedro De la Torre Luque, Daniele Gaggero et al. (+1 more)
We analyze 17 years of
Fermi-LAT data to study the diffuse $\gamma$-ray emission along the
Galactic plane and its connection to
cosmic-ray (CR) propagation. Accounting for correlated instrumental systematics, we find decisive evidence for a spectral break at $\sim20-30$ GeV, present across the inner
Galactic disk, with a preference of $\Delta\chi^2=39.78$ ($4.44 \sigma$ global). The energy and amplitude of this feature are in striking agreement with the spectral feature observed in local CR
nuclei, indicating that it is a global property of the
Galactic disk rather than a local phenomenon. The measured slope change, $\Delta\gamma \simeq 0.20$, is consistent with local CR data and with expectations from a transition in the CR
diffusion regime from Kolmogorov to Kraichnan
turbulence. Our results provide strong evidence that diffuse $\gamma$-ray emission along the
Galactic disk is dominated by $\pi^0-$decay emission up to a hundred GeV. These findings provide key insights into the origin of the CR spectral hardening and the propagation of CRs throughout the
Galaxy, and illustrate how this multimessenger approach can be used to probe the origin of features in the CR spectra, such as the long-studied CR Knee.
Read the full abstract ▾
All authors Fernando Valenciano, Pedro De la Torre Luque, Daniele Gaggero, Jorge Martin Camalich
Fluid Dynamics
Internal heating in rapidly rotating convection is not a shortcut to geostrophic turbulence
Justin A. Nicoski, Tobias G. Oliver, Stefano Maffei et al. (+1 more)
Convective
turbulence in
planets and
stars is often driven by internal heating. This forcing mechanism has also been proposed as a means of accessing the
diffusion-free scalings of the geostrophic
turbulence (GT) regime at modest forcing. We test this with the asymptotically reduced quasi-geostrophic model, which is formally valid in the limit of vanishing Ekman number, $Ek \rightarrow 0$, and retains the Prandtl number as an independent parameter. We find no such shortcut: the Nusselt and Reynolds numbers are no closer to their
diffusion-free predictions than in the boundary-heated case; the predicted $Pr^{-1/2}$ collapse fails over the range surveyed; and the prefactor depends on the form of the heating. Our no-slip/stress-free cases track the radiatively driven simulations of Hadjerci, Bouillaut, Miquel & Gallet (J. Fluid Mech., vol. 998, 2024, A9) case by case. Those simulations span only the narrow range of forcing over which the compensated Nusselt number is near its maximum within their geostrophic-
turbulence criterion; across the wider range accessible to the reduced model it rises to that maximum and then falls by more than an order of magnitude while the flow remains rotationally constrained. We argue that bulk transport scalings are incomplete diagnostics of GT, whereas the saturation of the interior mean temperature gradient and of the vertical velocity kurtosis remain reliable indicators.
Read the full abstract ▾
All authors Justin A. Nicoski, Tobias G. Oliver, Stefano Maffei, Michael A. Calkins
General Relativity and Quantum Cosmology
A Quasi-local Entropy for Black Hole Space-times
Raymond Isichei
We show that for static & spherically symmetric black hole geometries, the angular components of the Brown-York tensor on a finite radius boundary can be interpreted as the product of the Tolman-Ehrenfest temperature and a quasi-local
entropy. This
entropy vanishes at spatial infinity and monotonically increases as radius decreases, taking its maximum value on the horizon where it is equal to the Bekenstein-Hawking
entropy. Thus, the behaviour of this
entropy provides explicit verification of the covariant
entropy conjecture.
Read the full abstract ▾
General Relativity and Quantum Cosmology
Inspiralling Binary merger parameter reconstruction with lunar and satellite Laser Ranging
Miguel Vanvlasselaer
Precision tracking of Earth–Moon and Earth–satellite ranges offers a novel, low-frequency avenue for detecting gravitational waves from inspiralling massive black hole binaries, complementary to space-based interferometers. In this paper, we propose a first study of the reconstruction of the binary parameters from a synthetic set of range observations. Set-up: Assuming an ideal unperturbed Keplerian motion for the earth-satellite binary, we develop a framework for reconstructing the chirp mass $\mathcal M_c$ and luminosity distance $D_L$ of chirping sources from the perturbations they induce on ranging observables, using both Lunar
Laser Ranging (LLR) and a two-satellite ranging configuration (GUEST) as concrete case studies. Result: We find that chirp-mass recovery tightly converges as a power law in SNR ($\sigma_{M_c}/M_c \propto \mathrm{SNR}^{\alpha}$, $\alpha \simeq -1$ to $-1.8$) for both LLR and GUEST. In contrast, the luminosity distance suffers from a severe, SNR-independent degeneracy with the sky-orientation angles in the LLR configuration, yielding fractional biases and uncertainties of tens to over a hundred percent regardless of signal strength. The two-satellite GUEST configuration breaks this degeneracy and restores a convergent, SNR-dependent recovery of $D_L$ comparable in scaling to that of the chirp mass. These results demonstrate that multi-baseline ranging architectures are essential for extracting luminosity-distance information from ranging-based gravitational wave searches, while chirp-mass measurements remain reliably accessible even with a single ranging baseline such as the Earth–Moon system.
Read the full abstract ▾
Lattice Field Theory
Quantum Simulations of Two-Dimensional Non-Abelian Adjoint String Breaking
Anthony N. Ciavarella, Roland de Putter, Ed Younis et al. (+1 more)
Quantum computers offer the potential to directly probe the dynamics of strongly coupled
quantum field theories. As a step towards reaching this potential, local Krylov-based truncations of a pure SU(2)
lattice gauge theory on a triangular
lattice are constructed. Adjoint strings connected to dynamical
gluons are constructed in this truncated theory, and the resonances dominating the long-term dynamics at a large value of the gauge coupling are determined. Local operators are constructed to identify string oscillations and breakings. This is used to perform a
quantum simulation of adjoint string breaking on an $8\times8$ and $16\times8$-site
lattice with ibm_boston using all 156
qubits. Quantitative agreement with tensor network simulations is obtained for
circuits with 7,634 CZ gates with a two-
qubit gate depth of 218. In this simulation, the rates of oscillations and glueball production are identified with a distinctly non-Abelian signature of the underlying gauge group.
Read the full abstract ▾
All authors Anthony N. Ciavarella, Roland de Putter, Ed Younis, Ermal Rrapaj
High Energy Physics (Theory)
Holographic warped CFTs from General Relativity on AdS$_3$
Kristiansen Lara and Ricardo Troncoso
We introduce a new set of boundary conditions for three-dimensional Einstein
gravity with negative cosmological constant. The canonical generators plainly realize the semidirect sum of Virasoro and $u(1)$ Kac-Moody
algebras in its standard form, without the need of additional redefinitions of the global charges. We show that requiring Euclidean BTZ and thermal AdS$_3$ to be diffeomorphic precisely induces the warped modular $S$-transformation of the chemical potentials. The corresponding warped Cardy formula then exactly reproduces the Bekenstein-Hawking
entropy, where the ground state is identified as Euclidean AdS$_3$. An explicit comparison with the boundary conditions of Brown-Henneaux and Compere-Song-Strominger is also addressed.
Read the full abstract ▾
Strongly Correlated Electrons
Floquet engineering of competing antiferromagnetism and $d$-wave superconductivity on the square lattice
Zhaoyu Han and Subir Sachdev
We propose a driven Lieb–Hubbard
quantum simulator whose prethermal dynamics realize a square-
lattice spin-1/2
fermion model with independently tunable repulsive on-site and attractive bond interactions. Periodically modulating the charge-transfer offset between the site ($d$) and bond ($p$) orbitals of the Lieb
lattice brings a $p$-orbital doublon energetically close to a pair in the $d$
manifold while keeping all $p$-orbital singlons off resonance, thereby creating a synthetic “negative-$U$” center on a Lieb-
lattice bond site. Two controlled eliminations then generate a compact bond attraction in the reduced $d$-only model on the square
lattice, despite the microscopic repulsion in the $p$ orbital. The resulting interaction $J$ is tunable independently of the Hubbard repulsion $U_d$ on the $d$ orbitals, while interference between
photon-assisted paths provides access to an intermediate-coupling regime in which $J$ and $U_d$ are both comparable to the effective hopping. At half filling, a mean-field calculation in this regime finds adjacent
antiferromagnetic and $d$-wave superconducting phases, as well as narrow coexistence regions, suggesting close competition between these orders. We discuss the branch-preparation, prethermal, and higher-band conditions required to translate the formal construction into an optical-
lattice protocol. More broadly, our work identifies a structural similarity between Floquet systems and electron-
phonon problems that may guide the design of novel
quantum-simulation protocols.
Read the full abstract ▾
Earth and Planetary Astrophysics
Impacts of Correlated Noise on Retrievals of Exo-Earth Atmospheres
Nicole Wolff, Bruce Macintosh, Tyler D. Robinson et al. (+6 more)
The Habitable Worlds Observatory (HWO) aims to accomplish high-contrast imaging and spectroscopy of true Earth analogs for the first time. However, high-contrast spectroscopy with HWO may be limited by residual speckles which persist after deformable mirror correction and post-processing, hindering atmospheric characterization. Previous studies of self-luminous
giant planets showed that neglecting spectrally correlated errors due to speckles results in biased inferences of planetary parameters. Currently, HWO
retrieval studies generate spectra without noise spectral correlations. We present a Gaussian Process model of correlated noise of known properties in simulated HWO exo-Earth spectra, and the integration of this noise source into the forward and inverse modeling tool rfast. We quantify the impact of correlated noise on inferred molecular abundances and planetary properties across the ultraviolet/visible/near-infrared bandpass, for varying spectral resolutions (R), signal-to-noise ratios (SNR), and noise correlation length-scales (L). We find that, at the fiducial UV/Vis/NIR R=7/140/70 and SNR=10, including spectrally correlated noise at L=200 nm and L=10 nm yields a 57% and 161% higher average uncertainty on log oxygen abundance, compared to uncorrelated noise. Consequently, it is critical for both instrument design and post-processing
algorithms to minimize short length-scale chromaticity. Additionally, we find that a moderate resolution can constrain carbon dioxide (R$\geq 280$) and weakly detect methane (R$\geq2800$) abundances, demonstrating the benefit of a moderate resolution near-infrared spectrograph. These findings can aid the interpretation of future HWO reflectance spectra and set requirements on optical quality, instrument stability, and observing configurations.
Read the full abstract ▾
All authors Nicole Wolff, Bruce Macintosh, Tyler D. Robinson, Sarah Blunt, Jean-Baptiste Ruffio, Beck Dacus, Alex Madurowicz, Marshall Perrin, Laurent Pueyo
Earth and Planetary Astrophysics
On the Impact of Correlated Noise and Spectral Resolution on the Retrieval Analysis of the Habitable World Observatory
Ji Wang, Philipp A. Huber and Sascha P. Quanz
Finding signs of life elsewhere in the universe is the holy grail of the field of
exoplanets. Future space missions such as the Habitable World Observatory (HWO) are under development to search for biosignatures in
exoplanets. We investigate the impact of correlated noise and spectral resolution on the retrieved biosignature chemical abundances. At the nominal spectral resolving power R=140 for HWO, we show that in 40% of the simulated runs the retrieved biosignature (H$_2$O and O$_2$) abundances are at least 1-$\sigma$ off the input ground truth. At R=1000, the 1-$\sigma$ inaccuracy rate drops to 10%. We provide an empirical relationship between the retrieved biosignature abundance uncertainty and the amplitude of the correlated noise. As part of the mitigation plan to reduce the impact of correlated noise on
retrieval accuracy at low spectral resolution, we investigate the synergy between the HWO and LIFE space missions that cover ultraviolet, optical, and thermal-infrared wavelengths. After considering clouds and their effect on
planet albedo, we find that the two missions are complementary in that (1) more biosignatures (H$_2$O, CO$_2$, O$_2$, and O$_3$) are detectable with a broader wavelength coverage; (2)
retrieval uncertainty improves with the joint HWO+LIFE data set; and (3) LIFE is more sensitive to the atmospheric temperature profile, surface pressure, and
planet radius. This work provides evidence to support the choice of a medium resolution at R=1000 instead of R=140 for HWO and a quantitative relationship between the retrieved abundance uncertainty and the level of correlated noise at different spectral resolutions.
Read the full abstract ▾
Astrophysics of Galaxies
Shock-heated Away: The Impact of Radiative Cooling on Gas-Phase Transitions in Supernova Remnants
Zuzanna Kocjan, Benedikt Diemer, Vadim A. Semenov et al. (+2 more)
Supernova (SN) feedback plays a central role in regulating the structure of the interstellar medium (ISM) through the injection of energy and momentum. The amount of hot gas produced by a
supernova is a key quantity that determines how efficiently SN feedback heats the ISM and drives mass exchange between its different gas phases, here defined as cold ($T < 10^3\, \mathrm{K}$), warm ($10^3\, \mathrm{K} < T < 2\times10^4\, \mathrm{K}$), and hot ($T > 2\times10^4\, \mathrm{K}$) gas. However, previous studies have reported discrepant amounts of hot gas formed under otherwise similar ambient conditions. To resolve these disagreements, we quantify the amount of hot gas produced by individual SN explosions using a suite of controlled simulations spanning a broad range of ISM environments that include both uniform and turbulent, multiphase backgrounds. We show that radiative cooling is a key factor regulating hot-gas production, and that differences in cooling efficiency can account for some of the discrepancies reported in the literature. We derive a simple predictive relation for the peak hot-gas mass attained during the
evolution of a
supernova remnant in terms of the mean ambient density, the initial phase distribution, and the efficiency of gas cooling, which we parameterize as the cooling time over a key temperature range of $10^{4.5}\,\mathrm{K} \lesssim T \lesssim 10^{5.1}\,\mathrm{K}$. Finally, using tracer particles, we distinguish the evaporation of cold and warm gas into the hot phase and derive physically motivated expressions for the evaporation efficiency. Our results provide simple, predictive relations for hot-gas production and phase transitions that can be incorporated into subgrid models of SN feedback in
galaxy formation simulations.
Read the full abstract ▾
All authors Zuzanna Kocjan, Benedikt Diemer, Vadim A. Semenov, Shmuel Bialy, Uri Malamud
High Energy Astrophysical Phenomena
Galactic Science with Ultra-High Angular Resolution X-ray Imaging
Paul A. Draghis, Jeremy Hare, Mayura Balakrishnan et al. (+8 more)
Milli- to micro-arcsecond X-ray imaging will open a new observational regime for
Galactic astrophysics by resolving physical scales that are inaccessible to current X-ray observatories. This white paper highlights the science enabled by such capabilities across four broad questions: how particles are accelerated, how
stars die, how
accretion is fueled, and what populations of X-ray sources inhabit the
Galaxy. Ultra-high angular resolution will enable many new studies, such as resolving shocks and jets, measuring proper motions, parallaxes, and binary orbits, and providing secure multiwavelength counterpart identifications in crowded environments such as the
Galactic Center and globular clusters. Combined with high-time-resolution observations, these measurements will connect variability and transient events to the physical structures in which they originate, while coordination with gravitational-wave,
neutrino, $\gamma$-ray,
radio, optical, and infrared facilities will provide spatial information needed to identify and characterize multi-messenger sources. In addition to defining the science cases, this paper presents a curated list of compelling targets spanning various angular resolutions and outlines the complementary specifications necessary to maximize the scientific outcome. Accomplishing these science goals will require an instrument with high angular resolution, precise astrometry, substantial collecting area, sufficient spectral and timing resolution, and high dynamic range imaging capabilities.
Read the full abstract ▾
All authors Paul A. Draghis, Jeremy Hare, Mayura Balakrishnan, Poshak Gandhi, Tyler Holland-Ashford, Margarita Karovska, Thomas Maccarone, Herman L. Marshall, Mark Reynolds, Malgosia Sobolewska, Ryan Tanner
Astrophysics of Galaxies
Super-Eddington Little Blue Dots May Reionize Helium Too Early
Christopher Cain, Brent Smith, Gibson B. Bowling et al. (+5 more)
The James Webb Space
Telescope (JWST) has identified an abundant population of faint Active
Galactic Nuclei (AGN) at $z \gtrsim 4$ which display broad emission lines, compact morphologies, and blue ultraviolet–optical continua. These “Little Blue Dots' (LBDs) have been suggested to belong to the same family of objects as the more controversial “Little Red Dots' (LRDs), with differences between the two largely owing to viewing angle effects. In this scenario, super-Eddington
accretion resulting in high Extreme UV (EUV) and weak X-ray emission is invoked to explain the properties of both populations. We study the consequences of this super-Eddington scenario for the timing of Helium reionization. We find that observations which support an end to helium reionization no earlier than $z \approx 3$ disfavor scenarios in which the majority of observed $3 \lesssim z \lesssim 7$ LBDs are highly super-Eddington. For our fiducial super-Eddington
accretion scenario, we find that the fraction of the LBD population in this state must be $\lesssim 10\%$, assuming LBDs make up $5\%$ of the $M_{ m UV} < -18$
galaxy population and have average escape fractions of $15\%$, comparable to recent observations. Our constraint assumes that LBDs dominate the Helium reionization budget, and would be tighter if bright
quasars also contributed significantly. For a majority of LBDs to be super-Eddington, they would need to have small escape fractions ($\lesssim 1.5\%$) and/or be less abundant than observations suggest. Our conclusions are sensitive to the shape of the EUV spectra of super-Eddington black holes, motivating further study.
Read the full abstract ▾
All authors Christopher Cain, Brent Smith, Gibson B. Bowling, Yongda Zhu, Lily Whitler, Rafael Ortiz III, Anson D'Aloisio, Rogier Windhorst
Astrophysics of Galaxies
The GECKOS survey: Assembly history of the lenticular galaxy NGC 3957
Yuchen Ding, Marie Martig, Ling Zhu et al. (+24 more)
We analyse the assembly history of the edge-on lenticular
galaxy NGC 3957 using deep integral-field spectroscopic MUSE data from the GECKOS survey. By applying a
dust-corrected Multi-Gaussian Expansion and a population-orbit superposition model, we disentangle the
galaxy's
stellar kinematics, age, and
metallicity. We dynamically decompose the
galaxy and identify three distinct components: a dynamically-cold main disc, a compact
Nuclear Stellar Disc (NSD), and a hot component. The NSD emerges as the youngest and most metal-rich component ($t = 6.9 \pm 0.4$ Gyr; $[Z/H] = 0.49 \pm 0.06$ dex), implying that the
stellar bar is a long-lived structure that formed at least $\sim 7$ Gyr ago. The main
stellar disc is dynamically cold ($\sigma_z \sim 20-30$ km/s), precluding any significant mergers over the last $\sim 8$ Gyr, and exhibits a strong positive age gradient (younger inside, older outside) beyond the bar radius. Synthesising these dynamical fossil records, NGC 3957 likely evolved as a `faded spiral' in a small-to-medium group environment. Its outer disc might passively fade due to mild gas starvation, while the bar fuelled prolonged central
star formation. Comparison with S0s in the Fornax cluster reveals that this combination of internal secular
evolution and mild starvation produces `outside-in' fading signatures that could mimic the environmental stripping typically seen in dense clusters.
Read the full abstract ▾
All authors Yuchen Ding, Marie Martig, Ling Zhu, Amelia Fraser-McKelvie, Ryan Leaman, Glenn van de Ven, Jesse van de Sande, Francesca Pinna, Eric Emsellem, Francesca Fragkoudi, Yunpeng Jin, Adriano Poci, Camila de Sá Freitas, Matthew Frosst, Runsheng Cai, Scott M Croom, Timothy A Davis, Rory Elliott, Michael R Hayden, Jesús Falcón-Barroso, Dimitri A Gadotti, Antonino Marasco, Lucas M Valenzuela, Zixian Wang, Emily Wisnioski, Meng Yang, Tayyaba Zafar
High Energy Physics (Theory)
OPE and correlation functions in a generally covariant form
Arpit Das, Anatoly Konechny and Naveen Balaji Umasankar
In this paper we consider some general aspects of Euclidean conformal field theories on curved spaces of dimension $D\ge 3$. We first look at the OPE of scalar primary fields on conformally flat spaces. Extending the results of \cite{Konechny:2026bqg}, we give a general construction of the descendants' contributions to the OPE in the scalar channel. We then discuss CFTs on non-conformally flat spaces in the ambient space formalism. We investigate the short-distance behaviour of three-point functions on such spaces using the general ansatz proposed by Parisini, Skenderis, and Withers \cite{Parisini:2022wkb, Parisini:2023nbd}. We find that some additional corrections need to be added to the ansatz to ensure the existence of a local covariant OPE.
Read the full abstract ▾
Strongly Correlated Electrons
Determinant Quantum-Quantum Monte Carlo: Coherent Auxiliary-Field Sampling
Xuepeng Wang, Sagnik Banerjee and Debanjan Chowdhury
We introduce determinant
quantum-
quantum Monte Carlo (DQ$^2$MC), a
quantum algorithm that lifts the auxiliary-field sampling and averaging at the operational core of determinant
quantum Monte Carlo onto a
quantum computer. A determinant oracle synthesizes the DQMC amplitudes directly from a block encoding of the single-particle action
matrix via
quantum singular value transformations, so that the exponentially many Hubbard-Stratonovich weights are never enumerated, precomputed, or stored. Since the
fermions are free for fixed auxiliary fields, the construction operates entirely at the single-particle level, requiring $O(\log N_{\mathrm{st}})$ system
qubits and no Jordan-Wigner or Bravyi-Kitaev encoding, where $N_{\mathrm{st}}$ is the space-time volume. A full-
quantum protocol makes observables interference amplitudes, eliminating the Markov chain and its autocorrelation time altogether; a hybrid
quantum-classical protocol retains a constant-size active block of
qubits and replaces the Metropolis-Hastings acceptance step with an exact heat-bath draw, so that cluster updates of any size are rejection-free, and passes only classical information between updates, admitting parallel tempering and distributed execution across
quantum processors. The
circuit-depth scales more favorably with spatial volume than classical DQMC, at the price of a post-selection overhead determined exactly by the largest target probability —
polynomial for smooth distributions, exponential for sharply peaked ones. Finally, the reweighting
estimator underlying the
fermion sign problem maps exactly onto a
quantum weak value, placing the exponential cost of sign-problematic DQMC in precise correspondence with the post-selection overhead of weak-value extraction.
Read the full abstract ▾
High Energy Physics (Theory)
Carroll-Cotton Tensors and Gravitational Radiation at Null Infinity
Adrien Fiorucci, Simon Pekar, P. Marios Petropoulos et al. (+1 more)
We provide a first-principles definition of Cotton tensors on conformal Carroll geometries by gauging the conformal Carroll
algebra. On the mathematical side, this analysis yields a conformally covariant object designed to quantify deviations from conformal flatness in Carrollian geometries. On the physical side, it offers a powerful
geometric tool to describe gravitational radiative degrees of freedom at the conformal boundary of four-dimensional asymptotically flat spacetimes. Unlike the Bondi news, whose fully-covariant definition requires amendment by supplementary data that we identify with the Geroch tensor, the Carroll–Cotton tensors offer the natural
geometric objects to quantify deviations from stationarity due to the emission of gravitational waves.
Read the full abstract ▾
All authors Adrien Fiorucci, Simon Pekar, P. Marios Petropoulos, Matthieu Vilatte