Quantum Physics
Thermalization hierarchy from irreducible degrees of freedom
Pedro Fittipaldi de Castro and Wladimir A. Benalcazar
The decomposition of the
Hilbert space of a
quantum many-body system into the irreducible representations of its bond and commutant
algebras yields a finer structure of dynamically isolated subspaces than the mere decomposition into
symmetry sectors. While it has been recognized that subspaces associated with low bond-irrep dimensions $D_\lambda$ tend to violate the eigenstate thermalization hypothesis (ETH), here we show that $D_{\lambda}$ controls thermalization continuously across the full spectrum of dynamical subspaces. Using SU(2)-symmetric
spin-1/2 chains as a paradigmatic example, we demonstrate that $\mathrm{log} \ D_{\lambda}$ quantitatively accounts for the average eigenstate
entanglement entropy within each sector, establishing a thermalization hierarchy that interpolates from exact
quantum many-body scars at $D_{\lambda}=1$ to volume-law ergodic states at large $D_{\lambda}$. To make this concrete, we introduce the notion of irreducible degrees of freedom (IDOF), defined as the number of independently-varying spatial coordinates parametrizing a many-body state within a given bond-
algebra sector, which provides a microscopic interpretation of $D_{\lambda}$ and of the resulting thermalization hierarchy. Finally, we show that by selectively breaking
symmetries while preserving chosen bond-
algebra sectors, one can embed families of nonthermal eigenstates at prescribed
entanglement levels into an otherwise ergodic spectrum, generalizing restricted spectrum-generating
algebras from towers of individual states to entire dynamical subspaces.
Read the full abstract ▾
Strongly Correlated Electrons
Fixed-point tensor network for compactified boson conformal field theory
Gong Cheng, Dong-Yu Bao and Zheng-Cheng Gu
Fixed-point (FP) tensor networks provide a discrete spacetime representation of conformal field theories (CFTs), offering a new route toward understanding
holographic duality, generalized
symmetries, and even
quantum gravity. In this work, we construct FP tensors for the 2D compactified
boson theory at a generic compactification radius, an archetypal irrational CFT, using boundary (open-string) data with conformal boundary conditions. We show that the resulting tensors reproduce the closed-string spectrum with high accuracy and generate stable renormalization-group (RG) flows under the tensor complex renormalization
algorithm. Moreover, we identify a controllable exactly marginal deformation at the level of a single tensor, enabling flows that move continuously along the $c=1$
moduli space. This framework establishes a concrete
lattice-level route toward describing a broad class of 2D irrational CFTs.
Read the full abstract ▾
Cosmology and Nongalactic Astrophysics
Pulsar Timing Sensitivity to Dark Matter Substructure in the Presence of a Stochastic Gravitational-Wave Background
Abhiram Cherukupalli, Vincent S. H. Lee, Kim Berghaus et al. (+1 more)
Pulsar timing arrays (PTAs) can detect dark matter (DM) substructure through the small shifts a transiting DM subhalo imprints on pulse arrival times. Recently found evidence for a
stochastic gravitational-wave background (GWB) acts as red noise and competes with the substructure signal. Here we provide an analytic understanding of how this background degrades PTA sensitivity to DM substructure. We derive the full gauge-invariant proper-time observable induced by a transiting DM subhalo and develop a framework for the expected signal-to-noise ratio in the presence of red noise, accounting for the degeneracy with the
pulsar timing model. From this we obtain simple scaling relations for the reach across the static, dynamic, and
stochastic regimes, and numerically compute the reach for a Square Kilometre Array
benchmark at three representative points of the NANOGrav 15-year posterior. The GWB background suppresses the sensitivity to DM substructure by one to three orders of magnitude compared to forecasts in the presence of only white noise, and the suppression depends on the amplitude and spectral index of the background within a factor of three. The dynamic Shapiro signal suffers the smallest suppression and gives the best sensitivity to DM substructure near $10^{-2}\, M_\odot$. Probing the regime where subhalos make up all or part of the DM remains a challenge even for surveys with more
pulsars and longer observing time. Despite this, PTA measurements remain a competitive probe of DM substructure, and future surveys will increase in sensitivity by up to two orders of magnitude from existing NANOGrav limits.
Read the full abstract ▾
All authors Abhiram Cherukupalli, Vincent S. H. Lee, Kim Berghaus, Kathryn M. Zurek
Instrumentation and Methods for Astrophysics
How Low Can We Go? Minimum Spectroscopic Requirements For Supernova Subtype Classification
Willow Fox Fortino, Federica B. Bianco, Maryam Modjaz et al. (+2 more)
Millions of
supernovae will be discovered with the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). As a result, spectrographs around the world will have to make difficult decisions about which
supernova candidates receive spectroscopic follow-ups. This work identifies the minimum spectral resolution, $R_{\lambda} = \frac{\lambda}{\Delta \lambda}$, as a function of signal-to-noise ratio (SNR) at which spectral classification of
supernova subtypes becomes impossible. We include
supernova types Ia, Ia-91T, Ia-91bg, Iax, Ib, Ic, broad-lined Ic, IIb, IIP, and Ibn in this work. We produce a definition of SNR based on specific lines for each SN subtype that allows us to generate homogeneous
datasets at 16 different values of $R_{\lambda}$ and 14 different SNR's and we tested the classification performance of a recently developed deep-learning classifier, ABC-SN, on each $R_{\lambda}$ and SNR combination. We find that classification of
supernova spectra into a refined taxonomy that separates, for example, between different subtypes of stripped envelope
supernovae, is possible at low resolution and low SNR with no loss in model performance down to $R_{\lambda} = 50$ and $\text{SNR} = 5$. Classification performance is only minimally impacted even as low as $R_{\lambda} = 25$. We hope that astronomers using the LSST alert stream, as well as designers of future instruments and observatories, will benefit from knowing what spectral resolution is necessary to classify a
supernova for arbitrary \SNR{}.
Read the full abstract ▾
All authors Willow Fox Fortino, Federica B. Bianco, Maryam Modjaz, Thomas Matheson, Umer Zubair
High Energy Physics (Phenomenology)
A Dispersive Look at Rare $B$-meson Semileptonic Decays
Marco Ciuchini, Marco Fedele, Ayan Paul et al. (+5 more)
Rare semileptonic $b \to s$ flavour-changing neutral current transitions provide stringent tests of the Standard Model. Their interpretation is limited by hadronic uncertainties, notably the $B \to K^{(*)}$ and $B_s \to \phi$ form factors (FFs) and the
matrix elements of four-
quark operators. We perform a global analysis of $b \to s \ell^+\ell^-$ transitions taking these uncertainties fully into account, determining the FFs through the Dispersive
Matrix method and comparing a setup based solely on
lattice QCD (LQCD) with one that also includes light-cone sum-rule (LCSR) inputs at low $q^2$. Compared to the case where both input are taken into account, using only LQCD substantially enlarges the FF uncertainties at large
recoil. Combined with the latest LHCb and CMS angular measurements sensitive to strong phases, our global fit yields strengthened evidence in favour of long-distance hadronic effects rather than a short-distance shift in $C_9$. We further present new SM predictions for the theoretically clean $b \to s \nu\bar\nu$ modes, which depend only on local FFs, and a New Physics analysis of these transitions in the Weak Effective Theory, discussing their impact on the interpretation of the recent Belle~II measurement and on the available experimental upper bounds.
Read the full abstract ▾
All authors Marco Ciuchini, Marco Fedele, Ayan Paul, Josua Scholze, Luca Silvestrini, Silvano Simula, Mauro Valli, Ludovico Vittorio
Quantum Physics
Daylight quantum keyless private communication for free-space links
Pedro Neto Mendes, Preeti Yadav, Lourenço Sumares et al. (+3 more)
Quantum key distribution (QKD) is the most established approach in
quantum communication. However, long-distance free-space implementations, particularly satellite links, remain challenging, especially during the day due to daylight background noise.
Quantum keyless private communication (QKPC) is a
quantum communication protocol that enables information-theoretic security with simpler system requirements, improved robustness against noise, and without the need for secret key distribution. QKPC and QKD are complementary, with QKPC enabling free-space links where QKD is impractical, while QKD provides channel monitoring for applications that require eavesdropping detection. Here, we report a complete implementation of QKPC in a daylight free-space experiment over a 90 m rooftop link, using an experimentally simple setup. Our demonstration includes all stages of the protocol, from encoding and synchronization to message decoding, operates entirely without auxiliary classical synchronization channels, and is implemented offline through post-processing. This work demonstrates the feasibility of practical and scalable
quantum communication over high-noise daylight links and highlights the potential of QKPC as a complementary solution to QKD for future ground-based and space-based communication systems.
Read the full abstract ▾
All authors Pedro Neto Mendes, Preeti Yadav, Lourenço Sumares, Hugo Zbinden, Davide Rusca, Emmanuel Zambrini Cruzeiro
High Energy Physics (Theory)
Entanglement and geometric transitions in topological string theory
Gabriel Wong
How do we define a bulk subsystem in
quantum gravity? In \cite{Wong:2025kpz}, we argued that such a subsystem must support local
holographic degrees of freedom. These are gravitational edge modes, whose
entanglement creates a backreaction that fuses together subregions of spacetime. In this work we give a realization of these ideas in topological string theory, building upon \cite{Donnelly:2020teo,Jiang:2020cqo}. In this theory, a subsystem for closed strings consists of open strings ending on
entanglement branes, which play the role of a dynamical entangling surface. Local holography is implemented by the
geometric transition of these branes. We define a subregion open string
algebra and develop a diagrammatics for open string modular flow for arbitrary states and subregion. We check that the
entanglement entropy of these open strings reproduces the gravitational
entropy of the associated closed string background. Finally, we relate these local transitions to defect holography.
Read the full abstract ▾
Cosmology and Nongalactic Astrophysics
Disentangling modified gravity and galaxy bias with field-level inference
Sophie Hoyland, Daniela Saadeh, Kazuya Koyama et al. (+1 more)
We present a field-level inference framework for testing
gravity with large-scale structure, exploiting the full information of the
galaxy distribution. Traditional analyses based on the power spectrum discard non-Gaussian and
Fourier phase information, resulting in strong degeneracies between modified
gravity (MG) and
galaxy bias. Our approach overcomes this limitation by performing a
Bayesian analysis directly on the three-dimensional
galaxy number counts, jointly constraining MG and bias parameters using both amplitudes and phases. As an illustrative application, we analyse mock data in real space in the context of $f(R)$
gravity and a non-linear
galaxy bias model designed to mimic the real-data 2M++ BORG analysis of Jasche&Lavaux (2019). Non-linear structure formation is modelled using COmoving Lagrangian Acceleration (COLA) under different
gravity strengths, parameterised by $f_{R0}$. The resulting dark-matter fields are then mapped to mock
galaxy catalogues via a non-linear bias prescription. We demonstrate that, with the initial phases assumed known, including non-Gaussian and phase information yields tighter constraints on both $f_{R0}$ and the primary bias parameter $\beta$ (corresponding to the linear
galaxy bias on large scales), relative to power-spectrum-only analyses. Notably, the field-level approach breaks the degeneracies between MG and
galaxy bias inherent to two-point statistics. Through a
cosmic-web classification into voids, walls, filaments and clusters, we find that under-dense regions are the primary drivers in distinguishing
gravity at the field level. Finally, we establish the robustness of our pipeline against variations in initial conditions, Poisson noise, and
galaxy-field thresholding, providing a powerful path forward for field-level tests of
gravity.
Read the full abstract ▾
All authors Sophie Hoyland, Daniela Saadeh, Kazuya Koyama, Harry Desmond
Chemical Physics
AquaGen: Scaling generative models to molecular dynamics precision on thousands of atoms
Emmanuel Bengio, Sanjeev Raja, Yui Tik Pang et al. (+5 more)
We present AquaGen, the first all-atom, explicit solvent, periodic-boundary-condition-aware generative model that produces molecular configurations from the Boltzmann distribution at a fraction of the cost of molecular dynamics (MD). This is in contrast with existing generative models that remove degrees of freedom by operating on coarse-grained,
vacuum, or implicit solvent systems. Operating at this resolution allows for post-processing through force field energy evaluations and MD simulations, and enables the prediction of relevant properties in a gray-box manner (as ensemble averages of potential energy evaluations over generated samples). We demonstrate the utility of this paradigm on absolute hydration free energy (AHFE), producing estimates 4-10x faster and with comparable accuracy to standard GPU-based MD. By generating uncorrelated samples from alchemical Boltzmann distributions, we create more accurate, interpretable, and refinable ensemble predictions with calibrated uncertainty estimates, unlike regression methods which are entirely black-box predictors. Our approach also yields predictable benefits from increasing train- and test-time compute, realized by scaling model size and generating more samples, respectively. We believe that this approach demonstrates the utility of high-resolution ensemble generation for free energy estimation, with future potential to replace MD in tasks such as the prediction of lipophilicity, membrane permeability, or absolute binding free energy (ABFE) – whose grounding and interpretability may be critical for the development of new drugs and materials.
Read the full abstract ▾
All authors Emmanuel Bengio, Sanjeev Raja, Yui Tik Pang, Kerstin Klaeser, Cristian Gabellini, Nikhil Shenoy, Francesco Di Giovanni, Prudencio Tossou
Mesoscale and Nanoscale Physics
Robustness of quantized Hall resistivity under cavity coupling at zero temperature
Juan Román-Roche, Jie Wang, Michael Ruggenthaler et al. (+2 more)
Recent experiments have shown that strong light-matter coupling in electromagnetic cavities can modify transport properties of
quantum Hall systems through the formation of Landau polaritons, prompting questions about the robustness of topological protection. While earlier theory demonstrated that the
Hall conductivity can be modified at finite temperature and finite polariton lifetime (or finite broadening), experiments primarily probe the resistivity tensor. Our phenomenological model reveals an asymmetry between conductivity and resistivity in
quantum Hall systems under strong light-matter interaction, showing that at zero temperature the
Hall resistivity remains completely immune to cavity-induced modifications arising from polariton broadening, independent of the light-matter coupling strength. These results provide a deeper explanation for the absence of renormalization in the von Klitzing constant in experiments probing the even QH plateaus through the
Hall resistivity at low temperature, and clarify the distinct roles of dissipation and strong light-matter coupling in hybrid light-matter systems.
Read the full abstract ▾
All authors Juan Román-Roche, Jie Wang, Michael Ruggenthaler, Angel Rubio, Vasil Rokaj
Mathematical Physics
The Oracle Theorem for Matrix-Valued Jacobi Operators
Silas L. Carvalho and Douglas C. P. Freitas
This paper develops the
matrix-valued analogue of the reflectionless and oracle framework for Jacobi operators. Starting from
matrix-valued Weyl–Titchmarsh $m$-functions on the Siegel upper half-space, we study the distance-decreasing action of transfer
matrices,
matrix-valued harmonic measures and value distribution convergence. These ingredients are then used to establish the reflectionless property of the $\omega$-limit set and to prove an Oracle
Theorem for
matrix-valued Jacobi operators with absolutely continuous spectrum of full multiplicity.
Read the full abstract ▾
Earth and Planetary Astrophysics
The recent crossing of the 7:3 resonance between Ganymede and Callisto
Giacomo Lari and Mattia Rossi
Io, Europa and Ganymede are locked in the well-known Laplace resonance, while Callisto is not, even though it is very close to the 7:3 mean motion resonance with Ganymede. When considering the estimated
tidal dissipation in the Jovian system and the consequent orbital migration rate of the moons, it follows that the 7:3 resonance should have been encountered around two million years ago. Through accurate numerical simulations, we investigated the dynamical effects of the 7:3 resonance crossing on the recent orbital
evolution of the Galilean moons. We found that the most probable dynamical pathway is that Ganymede and Callisto were not captured into resonance, not even temporarily, while their eccentricities experienced a downward kick because of the resonance crossing, reducing their mean values of about 16% and 5%, respectively. Since this kind of
evolution requires a value of the eccentricity of Ganymede before the resonant encounter slightly larger than today's, it follows that
tidal dissipation within the moon must be low. In fact, a null free eccentricity of Ganymede would have led to an almost certain capture into the 7:3 resonance that would have survived until today. As a result of the resonance encounter, the amplitude of the free libration of the Laplace resonant angle increased, providing an explanation for its current value. Moreover, we found evidence that a three-body resonance crossing between the three outer moons occurred within the last few tens of thousands of years.
Read the full abstract ▾
Earth and Planetary Astrophysics
A Bayesian Search for Planet Engulfment Signatures in Solar Analogs
Zimo Cheng, Sharon Xuesong Wang, Fan Liu et al. (+11 more)
We present a systematic
Bayesian search for chemical fingerprints of
planet engulfment in 113
solar twins and analogs with high-precision abundance measurements, 45 of which host known or candidate
planets or brown-
dwarf companions. We constructed a
Bayesian framework with three sets of abundance models: random scatter,
Galactic chemical
evolution, and
planet engulfment with bulk Earth or CM chondrite compositions. Through model comparisons, we identified three candidates whose abundance patterns strongly favor
planet engulfment over the alternatives, with inferred engulfed masses of about 7.5-33 Earth masses. Our findings correspond to a nominal detection rate of 1-3% for
planet-engulfment signatures among
solar analogs. This work extends abundance-based engulfment searches beyond the binary-
star context and provides a framework for probing
star-
planet co-
evolution with
solar analogs, which goes beyond the commonly used abundance-condensation-temperature correlation (Tc slope).
Read the full abstract ▾
All authors Zimo Cheng, Sharon Xuesong Wang, Fan Liu, Haiyang Wang, Qinghui Sun, Johannes Buchner, Mia Babatsikos, Huiling Chen, Jiayue Zhang, Yuan-Sen Ting, Zhen Guo, Aaron Dotter, Serat M. Saad, Javier Osses
Chaotic Dynamics · Cross-listed from math.DS
Numerical Computation of Quasiperiodic Reducible Saddle-Node Bifurcations: a Parameterization Method Approach
Jordi-Lluís Figueras, Joan Gimeno and Jeremy P. Parker
We present a method for computing reducible, normally
hyperbolic, invariant
tori with internal quasiperiodic dynamics in autonomous ordinary differential equation systems. The approach is based on the parameterization method of KAM theory; thus, it is a Newton scheme with small divisors. Since the inner dynamics of the
torus is prescribed, the corresponding system parameters for which such a
torus exists are simultaneously determined. The method is amenable to a form of pseudo-arclength continuation, enabling the traversal and computation of saddle-node bifurcations. We give explicit
algorithms for the methods and demonstrate their applicability with two numerical examples.
Read the full abstract ▾
Instrumentation and Detectors
A high-sensitivity resistance bridge for nanoscale thermal microscopy
Wilfrid Poirier, Victor Guillemot, Mohammed Mghalfi et al. (+2 more)
Measurements of heat flux between micro-objects, in
vacuum or in air, are challenging because of their small size and the low thermal conductance of the medium between them. One way to address this issue consists in using a scanning thermal microscope (SThM) equipped with a temperature dependent resistance thermometer. However, this requires an instrument able to both injecting a defined heating Joule power and performing highly-sensitive resistance measurements. Here, we present such an instrument based on a Wheatstone bridge equipped with three Kelvin arms. It can perform resistance measurements in the range from 100 $\Omega$ to 1000 $\Omega$ not only in direct current but also in alternating current regimes at frequencies up to a few tenths of kHz. We first show that measurements of resistance standards are accurate to within one part in $10^4$ with a relative experimental standard deviation which can be as low as one part in $10^8$ for one second measurement. The instrument is then tested with a SThM thermometer. With the support of an electro-thermal model considering thermal time constants of the thermometer, we explain the frequency dependence of detected signals and optimize the measurement protocols of temperature and heat flux. By measuring sub-mK temperature variations, this instrument is then used to determine with a few nanowatts uncertainty the near-field radiative heat flux between a heated glass microsphere and a glass substrate, which is caused by the coupling of surface
phonon-polaritons.
Read the full abstract ▾
All authors Wilfrid Poirier, Victor Guillemot, Mohammed Mghalfi, Valentina Valentina Krachmalnicoff, Yannick De Wilde
Quantum Physics
Driving collective RPA modes by a time-dependent Dyson map
Andreas Fring and Marta Reboiro
We study a time-dependent non-Hermitian generalisation of the Schütte-Da~Providência model describing a bosonic mode coupled to collective particle-hole excitations. Using a time-dependent Dyson map, we construct a Hermitian counterpart and reduce the collective fermionic sector by means of the random phase approximation (RPA). The resulting dynamics is mapped to two time-dependent harmonic-oscillator branches with instantaneous RPA frequencies $W_\pm(t)$. We determine the corresponding stability regions and compute transition probabilities between instantaneous oscillator states. In first-order instantaneous-basis perturbation theory the leading transition $n\to n+2$ is proportional to $\dot W_j/W_j$, showing that it is purely nonadiabatic and absent in the time-independent case. We compare this result with exact Lewis-Riesenfeld transition amplitudes within the RPA approximation. Numerical examples show that different components of the Dyson map provide distinct driving mechanisms: the scaling parameter modulates the effective coupling, while the squeezing parameter acts through a moving-boundary contribution. In both cases the induced collective transitions exhibit parametric-resonance peaks and sideband structures.
Read the full abstract ▾
Instrumentation and Detectors
Online Data Reduction with Spiking Neural Networks: A Temporal-Coincidence Encoder and Distributed SNN for the ePIC dRICH Detector
Pierpaolo Perticaroli, Roberto Ammendola, Andrea Biagioni et al. (+10 more)
The dual-radiator Ring Imaging Cherenkov (dRICH) detector of the ePIC experiment at the Electron-Ion
Collider (EIC) will read out $\sim$320,000 silicon photomultiplier (SiPM) channels at a bunch-crossing rate of 100 MHz. The dark count rate (DCR) of the SiPMs is expected to rise up to 300 kHz per channel over the experiment lifetime, saturating the output bandwidth and requiring an online data reduction factor of at least five. Most crossings contain only uncorrelated DCR hits, while genuine Cherenkov hits cluster within $\sim$2 ns of the 10 ns crossing window: an intrinsically temporal discrimination problem. We present a two-stage online data reduction pipeline based on spiking neural networks (SNNs). The first stage is a per-photodetection-unit leaky-integrate-and-fire (LIF) temporal coincidence encoder that converts raw SiPM hits into a sparse spike stream, achieving over 90% data sparsification before any learned classifier is applied. The second stage is a distributed SNN (30 sub-sector networks plus an aggregation network) deployed on FELIX-155 DAM boards and a dedicated Trigger Processor board, classifying each crossing as Noise-Only or Signal+Noise. On simulated ePIC events the system reaches a true positive rate above 94% at a true negative rate of at least 80% across the full DCR range; an optional early-exit strategy reduces the average classification latency to $\sim$2 algorithmic timesteps at the cost of a few percentage points on both metrics. A hardware proof-of-concept on an AMD Versal Premium FPGA, integrating the LIF encoder with the AIGOR multi-core neuromorphic architecture, validates a single sub-sector pipeline at $\sim$1.7 MHz throughput; ongoing work targets 100 MHz through an identified set of optimizations of the inference fabric. The methodology may be relevant to other timing-driven detector applications at high rate.
Read the full abstract ▾
All authors Pierpaolo Perticaroli, Roberto Ammendola, Andrea Biagioni, Ottorino Frezza, Francesca Lo Cicero, Michele Martinelli, Pier Stanislao Paolucci, Elena Pastorelli, Luca Pontisso, Cristian Rossi, Francesco Simula, Piero Vicini, Alessandro Lonardo
Mesoscale and Nanoscale Physics
Graphene Electric Double-Layer Transistors for Enhanced-Sensitivity Label-Free Detection of Human Serum Albumin
Arslan Liaquat, Ghassem Baridi, Federico Rapuzzi et al. (+14 more)
Accurate detection of human serum albumin (HSA) is essential for the early diagnosis and monitoring of renal and hepatic disorders. We present a
graphene-based electrolyte-gated field-effect transistor (EGFET) for label-free, real-time quantification of HSA under non-Faradaic operation. Devices exploit the high interfacial capacitance of the electric double layer (EDL) to transduce electrostatic perturbations induced by albumin adsorption into measurable conductance modulation. Negatively charged HSA molecules induce systematic modulation of the
graphene channel, producing a concentration-dependent displacement of the Dirac voltage consistent with p-type doping. To establish a molecular-level interpretation of the sensing response, Brownian Dynamics simulations show that HSA adsorbs onto
graphene through multiple adsorption orientations associated with heterogeneous interfacial charge distributions and variable dipole
alignments relative to the surface. Adsorption is energetically stabilized by van der Waals interactions. Analysis of transfer characteristics across concentrations ranging from 0.01 to 30mgmL-1 reveals a correlation between surface charge density and carrier transport modulation within the electric double layer. Optimized devices exhibit a limit of detection of 0.0087 mg mL-1 and a linear dynamic range extending to 10 mg mL-1. The response remains non-Faradaic under sub-volt operation with reversible and reproducible behavior. The use of an inverse-mobility analytical metric highlights the role of disorder-enhanced carrier scattering in signal amplification, enabling sensitive electrostatic detection while preserving reversible device operation. These results establish
liquid-gated
graphene EGFETs as a promising platform for quantitative
protein sensing and provide insight into disorder-mediated transport mechanisms in
graphene bioelectronic devices.
Read the full abstract ▾
All authors Arslan Liaquat, Ghassem Baridi, Federico Rapuzzi, Daniele Goldoni, Vito Clerico, El Hadj Abidi, Yahya Moubarak Meziani, Mario Amado, Enrique Diez, Naveen Kumar, Camilia Coletti, Beatrice Cipriani, Hender Lopez, Giorgia Brancolini, Leonardo Martini, Luigi Rovati, Francesco Rossella
Astrophysics of Galaxies
Discovery of a low surface brightness galaxy in the Zone of Avoidance using VVVX Deepstack imaging
J. L. Nilo-Castellón, L. Baravalle, D. Minniti et al. (+12 more)
We report the discovery of VVVX J080705.96-273823.6, the first low-surface-brightness
galaxy candidate identified in the Zone of Avoidance by the VISTA Variables in the Via Lactea eXtended Survey (VVVX). The source was detected serendipitously during a visual inspection of the new Deepstack images, reconstructed mosaics generated through an updated reprocessing and stacking procedure that significantly improves the depth and spatial uniformity of the original survey images. First-order morpho-photometric parameters were obtained using SExtractor together with PSF models derived with PSFEx, applied to
star-subtracted images to minimize foreground contamination. Structural properties were derived from PSF-convolved modeling of azimuthally averaged surface-brightness profiles in the J, H, and Ks bands using exponential, Sersic, and composite models. The
galaxy candidate is clearly detected in all three near-infrared bands. The profiles are consistently described by an exponential disk, with scale lengths of 32-36 arcsec and extinction-corrected central surface brightnesses of 19.82-22.35 mag arcsec^-2. The J band provides the best-constrained profile, while H and Ks show the same behavior with larger uncertainties. The projected proximity to ESO 494-25 and ESO 494-26 suggests a possible physical association. If located at the same distance (11-12 Mpc), the exponential scale length would be about 1.8-2.0 kpc, consistent with nearby LSB disk
galaxies, although the lack of a spectroscopic
redshift prevents confirmation. This discovery demonstrates that the new VVVX Deepstack products can reveal faint diffuse
galaxies at low
Galactic latitudes, opening a path toward a more complete census of the obscured nearby Universe.
Read the full abstract ▾
All authors J. L. Nilo-Castellón, L. Baravalle, D. Minniti, M. V. Alonso, G. Galaz, C. Villalon, R. Hinojosa, E. O Schmidt, C. Valotto, M. Soto, E. G. Rivera, V. Valdivia-Rojas, D. Alvarez-Rocha, P. Marchant Cortés, N. J. G. Cross
Quantum Physics
Semiclassical Langevin dynamics of long-range dissipative time crystals
Reyhaneh Khasseh, Rosario Fazio and Angelo Russomanno
We develop a semiclassical Langevin approach to study finite-size effects in dissipative time-crystalline
spin systems. For a
spin-$1/2$ model with power-law Lindblad operators, we find finite-size oscillations exponentially decaying in time, and their decay rate decreases algebraically with system size in the long-range regime. The scaling exponent of this decay time provides a direct diagnostic of the robustness of the time-crystalline, and we find that this robustness extends beyond the range of power-law dissipation exponents where the system dynamics is mean-field in the thermodynamic limit. We also apply our approach to a
spin-one model with local dissipation and long-range
Hamiltonian interactions, formulating it in terms of Gell-Mann variables. In this case, finite-size stability is quantified through the deviation time from the mean-field behavior and the behavior of the dominant
Fourier peak. We find that both quantities scale as a power law with the system size – marking thereby a time-
crystal behavior – when the exponent of the power-law interaction is below a certain threshold, that turns out to be in agreement with previous cumulant-expansion findings. Our results show that semiclassical Langevin dynamics provides a useful finite-size probe of dissipative time
crystals in regimes beyond exact Lindblad simulations.
Read the full abstract ▾
History and Philosophy of Physics
The influence of the Academy of Gondishapur on the formation of the House of Wisdom in Baghdad and the science of the Golden Age of Islam
Rizoi Bakhromzod
The purpose of this study is to determine the role of the Academy of Gondishapur in the formation of the Bayt al-Hikma (House of Wisdom) in Baghdad and the emergence of Islamic science in the 8th-10th centuries. The methodology combines comparative-historical and biographical analysis with a study of institutional continuity based on primary sources and contemporary scholarly literature. The results demonstrate that Gondishapur, the foremost scientific and medical centre of late Sasanian Iran, constituted the primary human, methodological, and institutional source for the Abbasid Bayt al-Hikma. The migration of specialists, especially the Bukhtishu dynasty, Yuhanna ibn Masawayh, and Hunayn ibn Ishaq, transferred Gondishapur's medical traditions, hospital organisation (bimaristans), and translation methodology to Baghdad. Gondishapur's experience also shaped the development of medical education and the compilation of pharmacopoeias within the Bayt al-Hikma. A comparative structural analysis of the two institutions reveals both institutional borrowings and the original features of the Baghdad model. The article concludes that the transmission of Gondishapur's heritage to the Bayt al-Hikma constituted sustained institutional continuity, laying the foundations for the large-scale synthesis of Greek, Persian, and Indian knowledge in the Arabic
language.
Read the full abstract ▾
High Energy Physics (Experiment)
Flow-Based Surrogates for High-Dimensional Likelihoods in Experimental Neutrino Physics
Mathias El Baz, Lorenzo Giannessi, Adrien Blanchet et al. (+1 more)
Precision long-baseline
neutrino experiments use near-detector data to constrain systematic uncertainties on the unoscillated
neutrino flux, a prerequisite for accurate oscillation parameter measurements at the far detector. When the constrained likelihood is high-dimensional and non-Gaussian, this procedure demands advanced statistical treatment. Here we show that normalizing flows provide faithful and portable likelihood models for this problem. Leveraging an initial Gaussian approximation of the likelihood, we train a hybrid architecture combining coupling transformations and autoregressive spline flows. We demonstrate the method on a representative near-detector likelihood replica with 110 systematic uncertainty parameters, 10 of which explicitly introduce non-Gaussianities in the posterior. The trained model achieves a relative effective sample size of 98%, compared with about 5% for the Gaussian approximation, and reproduces a Markov chain Monte Carlo reference while remaining closed-form, samplable, and pointwise evaluable, making it suited to downstream uncertainty propagation and future near-detector to far-detector fits.
Read the full abstract ▾
All authors Mathias El Baz, Lorenzo Giannessi, Adrien Blanchet, Federico Sánchez
Optics
Non-Diffractive Topological Spin Textures of Relativistic Twisted Fermion Beams
Andrei Afanasev and Carl E. Carlson
In optics and acoustics, in structured beams, non-diffracting polarization measures in clearly diffracting beams, and
spin direction distributions in the core of these waves that have Skyrmionic behavior have been found. We here study the equivalents of these for
fermions and show that in corresponding circumstances the non-diffractive
spin textures persist independently of
spin, statistics, or kinematics (or propagation speed of the structured wave). As a part of the study, we present LG solutions for Dirac particles valid for both relativistic and non-relativistic kinematics.
Read the full abstract ▾
Mathematical Physics · Cross-listed from math.SP
Localization and unique continuation for the Anderson-Bernoulli model with long-range hopping on $\mathbb{Z}$
Shihe Liu, Yunfeng Shi and Zhifei Zhang
In this paper, we study Anderson localization near the spectral edge for the Anderson-Bernoulli model on $\mathbb{Z}$ with long-range hopping. When the hopping has a rational Laurent symbol, a quantitative version of the unique continuation principle can be proved, and localization occurs. For the unique continuation in the general case, we give some counterexamples and prove a weaker result for hopping that decays faster than exponential rate. To the best of our knowledge, this is the first localization result for the long-range Anderson model with pure Bernoulli potentials.
Read the full abstract ▾
Optics
Analytic Theory of Phase Transitions in Optical Metamaterials
Jiahao Yan, Xiaoshui Lin, Junpeng Hou et al. (+2 more)
Optical metamaterials provide a versatile platform for engineering homogeneous electromagnetic media whose distinct phases are characterized by phase diagrams in constitutive-parameter space. However, existing studies of hyperbolicity, topological properties, and exceptional-point formation often rely on highly symmetric models or case-by-case numerical parameter scans, leaving a unified analytic framework that identifies phases and phase transitions directly from the constitutive tensors lacking. Here, we develop a general theory that yields exact analytic criteria for topological transitions, exceptional-point transitions, pinch-off Lifshitz transitions, and optical Lifshitz transitions in homogeneous media. Applying this framework to a tractable example of a gyroelectric medium with anisotropic chirality, we uncover exceptional rings and negative refraction induced by gyroelectric-
chiral coupling. By enabling the exact determination of phase boundaries, our theory provides a predictive framework for discovering previously unexplored electromagnetic phases and offers new principles for the systematic design of optical metamaterials.
Read the full abstract ▾
All authors Jiahao Yan, Xiaoshui Lin, Junpeng Hou, Qing Gu, Chuanwei Zhang
Chemical Physics
Photo-thermal 2D spectroscopy: a different type of action
Pavel Malý, Xiaoji G. Xu and Tomáš Mančal
Advances in multidimensional spectroscopy have seen the rise of action detection, where coherent response is encoded into incoherent signals. These are typically proportional to the excited-state population, an example in 2D electronic spectroscopy (2DES) is fluorescence-detected 2DES (F-2DES), and in 2D infrared (2DIR) tag-loss 2DIR (TL-2DIR). Very recently, a new type of photo-thermal action signal has been introduced in 2DIR, detecting the generated heat by atomic force microscopy-based 2DIR (AFM-2DIR). We present a unified theoretical framework for population- and heat-based 2D spectroscopy, highlighting their complementary features. In the infrared, TL-2DIR reflects the system linear response, whereas AFM-2DIR produces spectra resembling conventional 2DIR, with sensitivity to anharmonicity and mode coupling. Our model reproduces key experimental AFM-2DIR features, confirming measurement in a highly nonlinear regime. Extending photothermal detection to electronic spectroscopy, we compare F-2DES with proposed photo-thermal 2DES (PT-2DES). PT-2DES closely resembles conventional 2DES, while enjoying the advantages of action detection.
Read the full abstract ▾
Quantum Physics
Superposed circular motion Unruh effect in (3+1) dimensions
Taylor Cey, Cisco Gooding and Robert Mann
Using a recently-introduced
quantum control model for Unruh-DeWitt detectors in superpositions of classical trajectories, we investigate the response of a detector interacting with a massless scalar
quantum field in (3+1) dimensions along a superposition of circular trajectories. We present numerical results for the transition probability and effective temperature of such a detector in four distinct
geometric scenarios: (a) concentric, vertically-stacked trajectories, (b) planar, horizontally-displaced trajectories, (c) static central point and surrounding circular trajectory, and (d) concentric, planar circular trajectories. For Gaussian switching functions that are much broader than the acceleration timescale, in case (a) we find only minor deviations from the well-known, effectively thermal response of a single circular trajectory, whereas in case (c) we find a significant reduction in the effective temperature and greater variation with energy gap. We conclude with a discussion of a potential analogue implementation in ultracold atom systems.
Read the full abstract ▾
Earth and Planetary Astrophysics
The influence of composition gradients on giant planet radii
Henrik Knierim and Ravit Helled
The radius of a
giant planet is a key physical property. It encapsulates the outcome of its mass, composition, and thermal state, serving as a critical link between observations and the theory of planetary interiors. While traditional interior models assume distinct core-envelope structures, recent
gravity measurements of Jupiter and Saturn reveal complex interiors with deep composition gradients. Here, we combine an analytic framework with numerical
evolution simulations to elucidate how internal structures with composition gradients affect the planetary radius. We demonstrate that the spatial redistribution of heavy elements does not inherently alter the planetary size; rather, it is the resulting difference in total
entropy over time that drives observable radius variations. We show that this mechanism naturally establishes two distinct evolutionary regimes. During the first few gigayears of
evolution, composition gradients trap thermal energy deep within the interior, significantly affecting the planetary
evolution and internal structure. However, as the
planet cools and contracts, this “thermal
memory” fades and the total
entropy no longer depends on the
primordial conditions. Consequently, the planetary radius decouples from the internal distribution of heavy elements, becoming solely a function of the total mass and bulk composition. Our results present the physical origin of the mass-radius-composition relation and suggest that the use of simplified interior models for
giant exoplanets is legitimate only after the
planet has surpassed this evolutionary threshold. Our analysis establishes a thermodynamic constraint on the planetary structure: while composition gradients can temporarily modulate cooling, they cannot permanently sustain radius inflation, as the addition of heavy elements, regardless of their distribution, inevitably leads to planetary contraction.
Read the full abstract ▾
Materials Science
From Stacking Disorder to Cubic Order: Ice Crystallization from Deeply Supercooled Water
Yulin Lin, Weimin Guo, Suvo Banik et al. (+9 more)
Crystallization far from
equilibrium can generate morphologies that defy classical
crystal habits, yet the microscopic mechanisms linking atomic-scale disorder to emergent macroscopic order remain elusive. Here we use in situ cryogenic transmission electron microscopy with a membrane-encapsulated microdroplet platform to directly visualize the freezing of deeply supercooled water at molecular resolution. We show that homogeneous nucleation produces stacking-disordered ice composed of mixed hexagonal and cubic sequences, in which cubic ice initially exists only as isolated monolayers. The gradual thickening of these cubic layers constitutes the key kinetic mechanism that governs the entire crystallization pathway. As thickening proceeds, nanoscale, defect-free cubic ice germs nucleate on the basal planes of the disordered
lattice. These faceted cubic germs act as facet-registered kinetic seeds that enforce cubic twinning and sequentially multiply growth branches. This kinetic pathway reproducibly generates robust eight-branched dendrites with global cubic (octahedral)
symmetry, even though each branch remains highly stacking-disordered. At later stages, latent heat release drives a crossover to the thermodynamically favored hexagonal phase; remarkably, the pre-established global cubic
symmetry is retained. These results reveal how strong kinetic driving forces convert microscopic disorder into emergent macroscopic
symmetry, providing a general framework for understanding and controlling rapid crystallization far from
equilibrium.
Read the full abstract ▾
All authors Yulin Lin, Weimin Guo, Suvo Banik, Tao Zhou, Thomas E. Gage, Lei Yu, Maksim A. Sultanov, Martin Holt, Subramanian Sankaranarayanan, Peng Zhang, Ilke Arslan, Jianguo Wen
Lattice Field Theory
The nucleon unpolarized generalized form factors and Mellin moments up to fourth order
Constantia Alexandrou, Simone Bacchio, Martha Constantinou et al. (+3 more)
Nucleon Mellin moments of parton distribution are computed up to the fourth order in
lattice QCD. The computation is performed using one ensemble of twisted mass
fermions at the physical pion mass point. We employ boosted frames to access the higher-order Mellin moments of generalized parton distributions. We also extract the forward-limit Mellin moments $\langle x^{n-1}\rangle$ for $n=2,3,4$. These Mellin moments are used to construct unpolarized parton distribution functions and compare to phenomenological extractions.
Read the full abstract ▾
All authors Constantia Alexandrou, Simone Bacchio, Martha Constantinou, Christian Kummer, Yan Li, Gregoris Spanoudes