Quantum Physics · Cross-listed from cs.LG
Modelling Emotional Memory in Children with Tensor Networks
Henry Groves, Lucia F. Jackson, Barbara-Anne Robertson et al. (+1 more)
We demonstrate how emotional valence influences the order-dependent structure of children's recognition
memory: correct recall of a sequence of emotionally-valenced toys depended not just on the valence of a given toy itself, but also on the valence of the toys shown before and after it. Whilst standard psychological models confirm that order-dependence differs across an event (a set of toys shown in sequence), accuracy is low and the model does not reflect how
memory for an emotional object influences others in the set. A classical tensor network model factoring in valence is able to achieve a 77.98% accuracy in modelling the results of the study. While not strictly a “
quantum cognition” model, this massive increase in accuracy shows the value of
quantum-inspired methods for modelling order-dependent phenomena, such as emotional
memory. Further, the task protocol we introduce presents a novel, real-world tool for exploring emotional temporal
memory in children for analysis using classical and
quantum-like models of cognition.
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All authors Henry Groves, Lucia F. Jackson, Barbara-Anne Robertson, Jonte R. Hance
General Relativity and Quantum Cosmology
Thermodynamic Geometry, Heat Engines, and Topology of Sharma–Mittal ModMax-dRGT Black Holes
Hassan Hassanabadi, Abdullah Guvendi, Dhruba Jyoti Gogoi et al. (+2 more)
We investigate the thermodynamic structure of charged AdS black holes in ModMax nonlinear electrodynamics coupled to dRGT-like massive
gravity, incorporating Sharma–Mittal
entropy corrections. The thermodynamic geometry is analyzed using the Weinhold metric in the parameter space spanned by the horizon radius and electric charge. The resulting thermodynamic
Ricci scalar characterizes effective microscopic interactions, with
curvature singularities signaling extremal boundaries and degeneracies of the thermodynamic metric. We further construct a rectangular black hole heat engine in the extended phase space and derive an exact expression for its efficiency, demonstrating how the ModMax parameter and massive-
gravity couplings influence the enthalpy-based conversion of heat into work, while the Sharma–Mittal parameters modify the Carnot bound through corrections to the black-hole temperature. Finally, a topological analysis of the corrected temperature and generalized free energy reveals both conventional and novel critical points, and the associated conserved topological charge is investigated.
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All authors Hassan Hassanabadi, Abdullah Guvendi, Dhruba Jyoti Gogoi, Semra Gurtas Dogan, Farokhnaz Hosseinifar
Chemical Physics
Limitations of Classical Force Fields for Metal Coordination Modes in Proteins: A Multilevel Study of Ca$^{2+}$ in Integrin $\alpha_V\beta_3$
Levy Andrea, Frigerio Giulia, Grollier Jules et al. (+3 more)
Standard biomolecular force fields often present limitations in modeling metal coordination modes. Here, we combined classical and QM/MM molecular dynamics simulations to investigate the Ca$^{2+}$ mediated binding of cRGD to integrin $\alpha_V\beta_3$. The results demonstrate the inherent limitations of fixed-point-charge force fields in reproducing asymmetric binding modes and highlight the value of QM-based multilevel approaches to assess the correctness and accuracy of FF models and capture metal coordination modes in complex biomolecular systems.
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All authors Levy Andrea, Frigerio Giulia, Grollier Jules, Siani Paulo, Di Valentin Cristiana, Rothlisberger Ursula
Atmospheric and Oceanic Physics
Investigation of regional variations in CO$_2$ growth rates : Integrating Emission Inventories and Atmospheric Observations
Yogesh Bali, Darja Cvetković, Juan Gancio et al. (+7 more)
Atmospheric carbon dioxide (CO2) growth rates reflects the combined influence of anthropogenic emissions, biospheric carbon exchange, and
climate variability. While
climate mitigation is primarily evaluated using bottom-up emission inventories within political boundaries, there is a need to validate these emission reductions using atmospheric measurements. Here, we present a global top-down analysis of atmospheric CO2 growth rates using CAMS atmospheric CO2 reanalysis, EDGAR anthropogenic emissions, GOSIF
dataset and the Southern Oscillation Index (SOI) as a measures of biospheric activity, to quantify the relative influence of human and natural drivers. We find that atmospheric CO2 growth rate varies substantially across space and time but is dominated by natural carbon-cycle processes and global background trends. Anthropogenic emission signals are frequently masked by natural variability, making regional top-down detection of human emission changes difficult. The COVID-19 emission reductions in 2020, despite occurring during a neutral ENSO year, were not consistently reflected in regional atmospheric CO2 growth rates, highlighting the dominant roles of biospheric dynamics and atmospheric transport. Using unsupervised clustering and persistence analysis, we identify five characteristic carbon-cycle regimes. Spatial averaging removes much of the regional variability, leaving large-scale
climate as the dominant control in most regimes. The active biosphere is the main exception, where strong biogenic signals persist, underscoring the critical role of tropical forests in shaping atmospheric CO2 variability.
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All authors Yogesh Bali, Darja Cvetković, Juan Gancio, Adrián Gutiérrez-Arroyo, Sofia Vazquez Alferez, Xuan Tung Vu, Jin Yan, Pietro Zgaga, Fakhteh Ghanbarnejad, Nasrin Mostafavi Pak
Materials Science
A Magnetism-Aware Crystal Graph Neural Network with Explicit Magnetic-Sublattice and Exchange-Geometry Representations
Sourav Mal and Satadeep Bhattacharjee
Magnetic order in
crystals is governed by moment-carrying sublattices and ligand-mediated exchange pathways, yet standard
crystal graph neural networks do not explicitly distinguish
magnetic sublattices and encode bonds primarily through pair distances. We propose mCGCNN, a magnetism-aware
crystal graph neural network that augments the full structural graph with a dedicated
magnetic subgraph. The
magnetic stream performs angle-aware message passing between
magnetic centers using metal–ligand–metal exchange-path descriptors motivated by Goodenough–Kanamori–Anderson physics, while layer-wise cross-coupling transfers structural and ligand-environment information from the full
crystal graph. Separate pooling of the
magnetic sublattice preserves magnetism-specific information alongside the global structural representation. We evaluate mCGCNN for total
magnetic moment prediction on 49,462 crystalline materials with
ferromagnetic spin configurations from the Materials Project and find that the proposed model improves agreement with DFT
magnetic moments over established
crystal-graph approaches without requiring a large increase in model complexity. Material-level analysis shows that the largest gains are concentrated predominantly in complex transition-metal and oxygen-containing
magnetic compounds. Our results show that explicitly incorporating
magnetic sublattices and exchange geometry provides a physically motivated route to improved
crystal-graph representations for
magnetic materials.
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Quantum Physics
Beyond Worst-Case Branching: Quantum Tree Search via Amplitude Amplification
Andreas Wichert
In this work, we investigate
quantum tree search via amplitude amplification. Amplitude amplification generalizes Grover's
algorithm by replacing the Hadamard initialization with an arbitrary
unitary $A$, with Grover's
algorithm recovered as the special case of uniform initialization. We demonstrate the construction of a dynamic search tree of depth $m$ with query complexity $\sqrt{\left(b_{avg}\right)^m}$ where $b_{avg}$ denotes the average branching factor, improving upon the commonly assumed $\sqrt{\left(b_{max}\right)^m}$, where $b_{max}$ is the maximum branching factor. We further challenge the widespread assumption that amplitude amplification is inferior to
quantum backtracking. In fact,
quantum backtracking is unsuitable for problems that do not naturally admit a backtracking structure; in such cases, amplitude amplification yields improved query complexity. We observe that amplitude amplification constructs the search tree dynamically, rendering its internal structure inaccessible, a constraint that applies equally to
quantum backtracking. To address this, we propose sampling-based methods to estimate the tree structure, under the assumption that it approximates a normal distribution with increasing depth. Finally, we introduce a
quantum greedy search based on a lookahead heuristic inspired by the classical cognitive architecture Soar, which models human-like problem-solving strategies.
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Medical Physics · Cross-listed from q-bio.QM
Establishing the Minimal Clinically Important Difference (MCID) for Smartphone-Derived Gait Measures in Multiple Sclerosis
Mike D Rinderknecht, Bernhard Fehlmann, Dimitar Stanev et al. (+7 more)
Background: Digital health technologies allow for frequent, remote gait monitoring in people with multiple sclerosis (MS). However, to differentiate daily variability from actual disease progression in longitudinal data, established minimal clinically important differences (MCID) are required. Currently, there is limited literature defining these thresholds for digital gait metrics. Objective: To establish MCIDs for digital gait measures reflecting progression in MS. Methods: Digital gait measures were captured via daily, remote, smartphone-based Two-Minute Walk Tests in CONSONANCE (NCT03523858), a phase 3b study of ocrelizumab in progressive MS. Using an anchor-based approach, median changes from baseline at Week 96 on digital gait measures were computed for patients showing clinically meaningful worsening on either Timed 25-Foot Walk, Ambulation Score, Expanded Disability Status Scale, or 12-item Multiple Sclerosis Walking Scale. These changes were subsequently triangulated to derive the MCID estimates. Results: 243 patients with progressive MS (female: n=125 (51%); mean [SD] age: 49.3 [9.3]; mean [SD] EDSS: 4.8 [1.4]) had digital gait data available at baseline and Week 96. Median changes were generally consistent across anchors. Triangulated MCIDs are: Step Velocity = -0.16 m/s, Step Velocity Scaled to Walking Time = -0.18 m/s, Step Duration = 0.06 s, Step Length = -0.07 m, Total Number of Steps = -28, and Total Distance Walked = -24 m. Conclusion: These MCIDs provide a framework for interpreting meaningful gait changes and integrating digital measures into MS outcome evaluation. Beyond facilitating novel clinical trial endpoints to evaluate treatment efficacy, they enable objective, real-world monitoring to advance personalized patient care.
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All authors Mike D Rinderknecht, Bernhard Fehlmann, Dimitar Stanev, Cedric Simillion, Ernst Bos, Letizia Leocani, Agne Kazlauskaite, Gary Cutter, Helmut Butzkueven, Licinio Craveiro
Instrumentation and Methods for Astrophysics
Domain-Informed Multi-View Self-Distillation for Astronomical Light-Curve Representation Learning with JEPA
Yicheng Rui
Light curves describe temporal variations in the brightness of celestial objects. Learning robust representations of light curves is essential for large-scale automatic discovery in the dynamic universe, but existing time-series foundation models often struggle with the uneven sampling, complex noise, and wide range of physical timescales that characterize astronomical observations. We propose a domain-informed representation learning framework for irregular astronomical time series with Joint-
Embedding predictive architecture (JEPA), combining semantics-preserving views, uncertainty-aware tokenization, and multi-view self-
distillation. The encoders are trained with multi-view self-
distillation using LeJEPA regularization on the LEAVES
dataset and evaluated on the StarEmbed classification
benchmark. On StarEmbed, our model outperforms hand-crafted features on 15 of 16 classification metrics. In few-shot linear probing, it achieves macro-F1 scores of 42.56 $\pm$ 7.21 with one sample per class and 63.58 $\pm$ 1.20 with 100 samples per class, consistently improving over hand-crafted features. Beyond variable-
star classification, the learned representation supports similarity search, parameter estimation, and photometric zero-point drift detection. We further evaluate cross-domain adaptation on 12 heterogeneous irregular time-series
datasets from PYRREGULAR, where the adapted variant matches or exceeds previous state-of-the-art performance on 5
datasets, compared with at most 3 wins by any single prior baseline. These results demonstrate that domain-informed multi-view self-
distillation is an effective strategy for learning representations of irregular time series, while also highlighting that successful time-series representation learning requires domain-specific inductive biases rather than a universally optimal architecture.
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High Energy Physics (Phenomenology)
Pseudoscalar charmonium and bottomonium: light-front wave functions, distribution amplitudes and distribution functions
Zhen-Ni Xu, Zhao-Qian Yao, Cédric Mezrag et al. (+2 more)
Light-front wave functions play a central role in the program of understanding the structure of
hadrons as QCD bound states. Using continuum Schwinger methods, based on Dyson-Schwinger and Bethe-Salpeter equations, they can be computed directly within a framework connected to QCD. For light pseudoscalar
mesons, previous studies revealed an approximate separability of longitudinal and transverse lightcone momentum dependences in the LFWFs, leading to a simple relation between distribution functions and amplitudes. In this work, we extend those previous studies to the case of pseudoscalar charmonium and bottomonium, using the fictitious $\pi_s$
meson as a
benchmark. Motivated by the observed deviations, we propose a modified non-separable LFWF ansatz that successfully reproduces the properties of heavy pseudoscalar quarkonia and allows the calculation of zero-skewness generalised parton distribution functions, electromagnetic and gravitational form factors, and transverse charge and mass distributions.
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All authors Zhen-Ni Xu, Zhao-Qian Yao, Cédric Mezrag, Khépani Raya, José Rodríguez-Quintero
Materials Science
Radiation Damage of TF-1 and PbWO$_4$ Crystals with 20 MeV Electrons
Hamlet G. Mkrtchyan, Arthur H. Mkrtchyan, Vardan H. Tadevosyan et al. (+9 more)
We studied the radiation hardness of two types of
crystals, lead glass TF-1 and lead tungstate PbWO$_4$, using a 20 MeV electron beam from the LUE-75 linear accelerator at AANL. The transmittance of the
crystals in the wavelength range of 200-1000 nm was measured before and after irradiation, and after thermal annealing. % The irradiation was performed in two stages. First, both
crystals were irradiated with beam current of 0.125 $\mu$A, each for a total exposure time of 720 s and absorbing $5.6 \times 10^{14}~e^-$. % Strong degradation of the optical properties of TF-1 caused by this amount of radiation was observed, while the effect on PbWO$_4$ was negligible (it is a few tens of times radiation harder than TF-1). % In the second stage, only the PbWO$_4$
crystal was exposed to radiation, with a beam current of 0.28 $\mu$A and an exposure time of 1200 s, absorbing an additional $2.1 \times 10^{15}e^-$, still no notable effect. % Thermal annealing was performed in the temperature range of 160 to 250$^\circ$C (isochronal) for 10-12 hours. The transmittance of the annealed
crystals increased with the annealing temperature and time.
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All authors Hamlet G. Mkrtchyan, Arthur H. Mkrtchyan, Vardan H. Tadevosyan, Hrachya H. Marukyan, Argine S. Hakobyan, Ashot S. Hakobyan, Arthur A. Hoghmrtsyan, Diana G. Khurshudyan, Nina N. Prazyan, Albert H. Shahinyan, Adelina S. Stepanyan, Lusine R. Vahradyan
Popular Physics
Signs and Signatures of Intelligence
Julia DeMarines
Research into the emergence and
evolution of intelligence is underrepresented in astrobiology. I propose noosemiotics, the study of noosignatures, to address this gap. Noosignatures are the structured traces that minds leave on a medium, whether physical (tools, etchings, architecture) or signal-based (encoded transmissions, complex animal communication), that remain detectable as the products of intelligence regardless of whether their meaning can be recovered. Where biosignatures mark life and technosignatures mark technology, noosignatures mark the space between. This paper defines noosemiotics, situates it within astrobiology, and proposes a research program for empirical metrics, with material culture as the primary test bed.
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Optics · Cross-listed from eess.IV
A Zero-Shot Deep Image Prior Framework for Denoising and Deconvolution in Fluorescence Microscopy
Xiangyu Qian, Jing Liu, Yunqing Tang et al. (+2 more)
Fluorescence microscopy images are degraded by noise and diffraction-induced blur, which compromise structural fidelity and limit quantitative analysis. Supervised deep learning methods achieve impressive restoration performance but require large-scale paired
datasets that are difficult to obtain in practice. To address this issue, we propose SDIP, a zero-shot deep image prior (DIP) framework that sequentially performs denoising and deconvolution without external training data. An aSeqDIP-based module first suppresses noise while preserving fine structures through sequential autoencoding regularization. In the deconvolution stage, a wavelet-based background correction step is incorporated before the proposed RLG-DIP module performs artifact-reduced deconvolution. RLG-DIP uses the Richardson-Lucy deconvolution result as a physically consistent guidance prior, integrating the imaging model with the implicit prior of DIP to stabilize the ill-posed deconvolution process. Experiments on the BioSR
dataset across multiple cellular structures demonstrate that SDIP improves both signal-to-noise ratio and resolution, achieving superior visual quality and improved quantitative performance on most evaluated structures. The proposed framework may also provide useful insights for designing physically guided DIP methods for other inverse problems.
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All authors Xiangyu Qian, Jing Liu, Yunqing Tang, Luru Dai, Qiushi Li
High Energy Physics (Phenomenology)
Near-threshold scattering of proton and Omega baryon and possible bound states
Yu-Jie Feng, Qian Wang and Qiang Zhao
We study the near-threshold scattering and bound-state structure of the $N\Omega$ system by solving the Lippmann-Schwinger (L-S) equation within the framework of the
meson exchange model and the Pomeron exchange model. The numerical results indicate that after incorporating the Pomeron exchange mechanism, the observables of the ${^5}S{_2}$ channel, such as the binding energy, scattering length, and effective range, agree better with the experimental measurements. In addition, The Pomeron exchange can provide an extra attractive interaction to make the hadronic state more compact. We also predict the scattering behavior of the ${^3}S{_1}$ channel and confirm that a weak quasi-bound state exists in this channel. Future experimental measurements on the ${^3}S{_1}$ channel will provide an important criterion for verifying the dynamic role played by the Pomeron exchange mechanism within the $N\Omega$ system.
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Physics and Society
Drift Behavior in a Bounded-Confidence Opinion Model with Media Influence
Oliver Zheng and Mason A. Porter
People's opinions can change both from their interactions with each other and from their interactions with media sources. Bounded-confidence models (BCMs) of opinion dynamics provide one framework to study such dynamics. In a BCM, the nodes of a network are
agents with continuous-valued opinions, and these
agents interact with each other via the edges of the network. In this paper, we extend the original Deffuant–Weisbuch (DW) BCM by incorporating influence from two media sources – one with a positive value and one with a negative value – to capture the effects of a polarized media landscape. We show both numerically and analytically that our extended DW model exhibits drifting behavior in which a large cluster of opinions shifts toward one of the media
agents. We analyze how the drift trajectory and speed depend on the model parameters, and we identify conditions in which drift is promoted or suppressed. Our results provide insight into how competing media sources can influence collective opinion formation in social systems.
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High Energy Astrophysical Phenomena
Continuation of Force-Free Electrodynamics upon the loss of magnetic dominance
Morifumi Mizuno
Force-Free Electrodynamics (FFE) describes the
evolution of the electromagnetic field in magnetically dominated
plasmas, but ceases to be
hyperbolic once the
magnetic dominance condition $F^{ab}F_{ab}>0$ is lost. We demonstrate that, after the loss of
magnetic dominance, FFE may be replaced by a theory of null fields, $F^{ab}F_{ab}=0=F^{ab}\tilde{F}_{ab}$, characterized by the condition that its principal null direction is tangent to a geodesic congruence. In flat spacetime, this theory may be equivalently stated as the condition that the field satisfies $\vec{B}^2-\vec{E}^2=0=\vec{E}\cdot\vec{B}$ and the integral curves of the drift velocity $\vec{E}\times\vec{B}/\vec{B}^{2}$ are straight lines. We develop the general structure and the properties of this theory and test it against 1D PIC simulations using the collision of planar symmetric Alfvén waves. We find that the force-free combined with the null continuation shows remarkable macroscopic agreement with PIC simulations, including the birth and
evolution of the null region ($F^{ab}F_{ab}=0$) and the formation of a current sheet. As an independent test, we apply the null continuation to Adhikari's type-changing solution, an exact FFE solution exhibiting finite-time loss of
magnetic dominance, and also find macroscopic agreement with 1D PIC simulations.
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High Energy Astrophysical Phenomena
The Role of Scintillation in Detecting HI Absorption in FRB Spectra
Om Gupta, Pawan Kumar, Paz Beniamini et al. (+1 more)
The 21-cm absorption line of neutral hydrogen has been a long hypothesized observational feature of the spectra of Fast
Radio Bursts (FRBs). The difficulties associated with detector noise in extracting HI absorption have been previously studied. We test the role that scintillation plays in the HI absorption line's detectability, and characterize the regimes where a realistic FRB may yield the 21-cm line. We build an efficient model to simulate diffractive scintillation arising from FRB passage through a thin scattering screen. We find that the absorption profile is detectable in a scintillation-dominated high signal-to-noise spectrum if the scintillation decorrelation bandwidth differs significantly in scale from the width of the absorption profile. Active repeaters also enable favorable conditions as the absorption signal improves when repeat bursts are stacked. Repeat bursts must be separated in time by more than the diffractive scintillation timescale, otherwise flux modulations with frequency are correlated. By cross-referencing repeating FRB positions with an observational catalog of Milky Way molecular clouds detected in CO, we find that the sightline to FRB 20180916B may intersect a
Galactic molecular cloud. For currently operating and planned sensitive
telescopes, the presence of both scintillation and noise requires $\gtrsim 1000$ bursts to be stacked to detect the HI absorption line at a $5\sigma$ significance. Improvement in detector sensitivities will help probe HI clouds intersected by FRBs in the host or intervening
galaxies, or in high-
redshift minihalos.
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All authors Om Gupta, Pawan Kumar, Paz Beniamini, Edward L. Robinson
Quantum Physics
Diameter truncated operator evolution
Tom Holden-Dye, Max Marvell, Joel Mills et al. (+2 more)
We present a method for simulating operator dynamics in out-of-
equilibrium quantum systems. Due to the rapid growth of complexity in these systems, this is typically speaking an intractable task. However, exceptional progress has been made in recent years to sidestep this barrier, with the introduction of a number of methods that make use of a truncation of the simulation to low-weight (the number of non-trivial terms in a Pauli string basis expansion) observables, which turns out to be a good approximation for many dynamical quantities of interest, e.g., two-point infinite-temperature correlation functions between local operators. In this work, we extend this idea to a leaner truncation protocol, truncating operators based on their diameter - that is, the size of the region on the
lattice on which they are non-trivially supported. Using existing analysis for generic
circuits we argue that this kind of truncation protocol is physically well-motivated, and show via extensive numerical simulations for a number of systems of interest (here, the kicked Ising model and the Heisenberg XXZ model) that it is effective, and allows us to efficiently and accurately extract local correlation functions and transport properties.
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All authors Tom Holden-Dye, Max Marvell, Joel Mills, Christoper J. Turner, Arijeet Pal
Astrophysics of Galaxies
Kinematic detection of dusty outflows from active galactic nuclei: Polycyclic aromatic hydrocarbon kinematics of type 2 quasars with JWST/MIRI spectroscopy
Fergus R. Donnan, Cristina Ramos Almeida, Omaira González Martín et al. (+5 more)
Active
galactic nuclei (AGN) are thought to have dusty
outflows, but unlike in the gas phase, it is challenging to measure the kinematics of
dust. We present the detection and analysis of the kinematics of
dust in five type 2
quasars at $z\sim0.1$ from the
Quasar Feedback (QSOFEED) sample observed with JWST/MIRI spectroscopy. We used principal component analysis
tomography to produce velocity maps of polycyclic aromatic hydrocarbon (PAH) features, which are the smallest carbonaceous
dust particles. We were then able to compare velocity maps of the PAHs with emission lines of ionised and molecular gas. We produced velocity maps of the 11.3 $\mu$m PAH feature, which traces large and neutral PAHs, for three out of the five objects, where all three show an
outflow in the PAH kinematics. This becomes particularly clear after we subtracted disk kinematics, where the H$_2$ rotational transitions also show residuals consistent with an
outflow. Compared to previous work with Seyfert
galaxies, this work suggests that dusty
outflows are more common at higher Eddington ratios, $\lambda_{\rm Edd}\gtrsim0.1$, in agreement with previous suggestions, although the sample size is small. We were unable to produce velocity maps for the 6.2 $\mu$m PAH, which traces ionised PAHs, potentially due to differences in the intrinsic profile and/or suppression of the feature in AGN, which was seen previously in Seyfert
galaxies. This reflects studies of PAH band ratios where AGN
outflows have more neutral PAHs. This work demonstrates that dusty
outflows may be common, particularly at high Eddington ratios, and it therefore plays a key role in the
evolution and life cycle of AGN.
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All authors Fergus R. Donnan, Cristina Ramos Almeida, Omaira González Martín, Karin Sandstrom, Anelise Audibert, Marina Bianchin, Miguel Pereira-Santaella, Ismael García-Bernete
Cosmology and Nongalactic Astrophysics
Constraining primordial oscillations and inflationary particle production with Planck, ACT DR6, and DESI DR2
Simran K. Nerval, Renee Hlozek, Hidde T. Jense et al. (+1 more)
Non-standard inflationary models often predict oscillatory features in the
primordial power spectrum. We present constraints on general oscillatory templates for
primordial power spectra, including those that vary linearly and logarithmically with wavenumber, as well as oscillations induced by inflationary particle production. We utilize the Planck 2018 and Atacama Cosmology
Telescope Data Release 6
cosmic microwave background data as well as large-scale structure data from the Dark Energy Spectroscopic Instrument Data Release 2. To efficiently explore the
multimodal posteriors for these models as well as performing mode comparisons, we integrate the preconditioned sequential Monte Carlo sampler, pocoMC, into the widely used sampling code, Cobaya. We find that the combined
dataset tightens the 95% CL upper bounds on the general oscillation amplitudes to $A_{\text{lin}} < 0.021$, $A_{\text{log}} < 0.022$, and $A_{\text{log rf}} < 0.023$, restricting the amplitude to $\sim 2\%\, A_s$. For the inflationary particle production model, our analysis places a maximum a posteriori constraint on the coupling constant of $g = 0.034$. While these models all provide an improved fit to the data compared to the concordance $\Lambda$CDM model, the
Bayesian evidence still reveals a moderate preference for $\Lambda$CDM compared to models with general oscillations and is inconclusive regarding the particle production model, suggesting that the added complexity of these models beyond the standard model is not statistically justified by current data.
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All authors Simran K. Nerval, Renee Hlozek, Hidde T. Jense, J. Richard Bond
Superconductivity
Excitation of Collective Modes in a Chiral Superfluid by Thermal Quench
Noble Gluscevich and J. A. Sauls
Based on time-dependent Ginzburg-Landau field theory we show that rapid cooling through the second-order phase transition into superfluid $^3$He-A excites collective modes of newly formed
chiral domains, in addition to topological defects that are formed via the Kibble-Zurek mechanism. Simulations of temperature quenches in the presence of Gaussian space-time white noise generate a highly excited inhomogeneous condensate. Large-scale simulations exhibit a complex network of domain walls and
vortices. We report results for the excitation of bosonic collective modes by thermal noise as well as nonequilibrium temperature quenches, followed by coarsening dynamics tracked in terms of the
Fourier components of the order parameter amplitudes. For thermal states, the spectrum of bosonic excitations is defined by a power spectral density (PSD) for each mode, which is sensitive to the Langevin damping. For weak damping the PSD onsets sharply at the frequency corresponding to the mass of the bosonic mode, then decays as $1/\omega$. We also track the dynamics of the order parameter following a temperature quench. We report results for the scaling exponents of Kibble-Zurek freeze-out time and correlation length as a function of quench rate for several damping rates. The dynamical exponent $z$ is shown to transition smoothly from $z=1$ to $z=2$ as the damping is increased, while the correlation length exponent, $\nu\approx 1/2$, is independent of damping.
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Astrophysics of Galaxies
SKA$-$VLBI view of AGN jets in the early Universe
C. Spingola, M. Mezcua, Y. Liu et al. (+33 more)
Active
Galactic Nuclei (AGN) are among the brightest sources in the Universe, and those that are also jetted are uniquely valuable at the earliest epochs, because their relativistic
outflows can regulate the gas supply of their host
galaxies, potentially affecting both early
star formation and the rapid growth of supermassive black holes (SMBHs). Their compact, high-brightness-temperature
radio cores provide the sharpest beacons for very long baseline interferometry (VLBI), enabling direct constraints on Doppler boosting, jet duty cycles, and jet$-$environment coupling at extreme
redshifts. In this White Paper, we discuss how the SKA-VLBI will provide sub-$\mu$Jy sensitivity together with milliarcsecond (mas) angular resolution to image and characterise jetted AGN at $z>6$ across SKA-Mid and SKA-Low frequencies. These observations can directly test SMBHs ($>10^6$ M$_{\odot}$) formation/
evolution models (including jet-assisted super-Eddington phases) and infer the geometry of the Universe, directly probing the cosmological framework at high precision. Synergies with current and next-generation multi-band facilities will also be crucial to fully understand their host
galaxies and their environment, providing an unprecedented panchromatic knowledge of the first jetted AGN.
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All authors C. Spingola, M. Mezcua, Y. Liu, S. Frey, S. Belladitta, T. An, M. Giroletti, A. Caccianiga, A. Moretti, L. Ighina, T. Sbarrato, G. Migliori, D. Dallacasa, L. I. Gurvits, K. É. Gabányi, K. Perger, Z. Paragi, R. D. Baldi, E. Bañados, G. Bernardi, M. Bondi, E. De Rubeis, F. D'Ammando, F. De Gasperin, I. Delvecchio, F. Vito, K. Rubinur, M. Krezinger, R. Lico, E. Momjian, M. Orienti, J. Hodgson, C. Stanghellini, A. Wang, M. Latif, H. Cao
Cosmology and Nongalactic Astrophysics
First results of sub-arcsecond scale objects identified with ASKAP using interplanetary scintillation
R. Chhetri, J. S. Morgan, R. D. Ekers et al. (+4 more)
We present a catalogue of 131 compact $(\lesssim 0.1 \,arcsec)$ sources detected at 823 MHz via their Interplanetary Scintillation (IPS). These measurements were made with the ASKAP
telescope, across its full field of view of 35 square degrees, utilising all 36 Phased Array Feed (PAF) beams. To bypass ASKAP's standard correlator's minimum integration limit of 10 s, we used the CRAFT data capture system (CRACO), with visibilities sampled every 110 ms. Here we present the data processing steps, the sources detected, and their IPS-inferred properties. ASKAP IPS cleanly separates two populations: compact hot spots embedded in extended lobes and IPS-unresolved sources which are AGN or CSO sources associated with the
galactic nucleus. We also compare these results with the results from observations of IPS at 162 MHz with the Murchison Widefield Array, providing the spectra of compact components between 162 MHz and 888 MHz. These measurements further re-enforce the dominance of peaked-spectrum SEDs in the compact-source population at frequencies below 1 GHz. This pilot study using test data is a pathfinder for a more comprehensive ASKAP IPS survey which is underway.
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All authors R. Chhetri, J. S. Morgan, R. D. Ekers, E. M. Sadler, V. A. Moss, A. Waszewski, P. E. Gordon-Hall
High Energy Astrophysical Phenomena
The impact of stellar binaries and star cluster dynamics on pair-instability supernovae
Francesco Gabrielli, Cristiano Ugolini, Lavinia Paiella et al. (+12 more)
Pair-instability
supernovae (PISNe) are among the most luminous transients in the Universe. However, they have never been confidently observed. Solving this puzzle would have key implications for several astrophysical topics, including
galaxy chemical enrichment, the interpretation of gravitational waves from binary black hole mergers, and the nature of red dropout sources seen by JWST. With this aim, we present the first in-depth study of PISN occurrence in binary
stars, both in isolation and in dense
star clusters. We employ the SEVN code, with PARSEC
stellar tracks, to evolve a suite of 35 synthetic binary populations, including variations on formation channels, cluster properties, and upper limit of the
stellar initial mass function. We find that binary interactions can boost the PISN rate by up to threefold, relative to single
stars, whereas binary hardening can either enhance or suppress PISN production, depending on whether the progenitors are
primordial or dynamically formed. Moreover, we showcase how our comprehensive framework for the
cosmic PISN rate can be used to constrain uncertain aspects of
stellar and
galaxy evolution models, via comparison with observations, including the recipes for
stellar-wind mass loss in very-massive
stars, and the
galaxy metallicity distribution throughout the Universe.
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All authors Francesco Gabrielli, Cristiano Ugolini, Lavinia Paiella, Benedetta Mestichelli, Manuel Arca Sedda, Lumen Boco, Kendall Shepherd, Giuliano Iorio, Guglielmo Costa, Giovanni Gandolfi, Andrea Lapi, Erik Zackrisson, Thomas Nordlander, Alessandro Bressan, Mario Spera
Disordered Systems and Neural Networks
Stationary point complexity via minimal supersymmetry breaking
Jaron Kent-Dobias
The statistics of stationary points are a powerful way to understand mean-field random landscapes, and the Kac–Rice formula is a general way to compute them. A longstanding technical barrier to these calculations is the presence of the absolute value of the determinant of the Hessian. Neglecting the absolute value produces an elegant 2-index supersymmetric representation of the problem, but is often incorrect. We develop an expanded 4-index supersymmetric representation of the complexity problem which incorporates the absolute value naturally via spontaneous supersymmetry breaking along a particular superspace direction. Positing that no additional
symmetry breaking occurs implies the reduction to five order parameters corresponding to elements of a superspace operator
algebra generated by the spontaneously SUSY-breaking operator. We relate the order parameters to the geometry and spectra of stationary points, showing that the SUSY-breaking order parameter corresponds to the spectral density of the Hessian at zero
eigenvalue. We give examples of this formalism applied to calculate the annealed complexity of several models, including the perceptron and the Sherrington–Kirkpatrick model. The framework is naturally extended to quenched complexity, where each order parameter corresponds to a replica
matrix.
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High Energy Physics (Phenomenology)
Particle Production from Inhomogeneities: the off-shell side of gravitational waves
Michele Redi and Andrea Tesi
We continue the study of particle production from gravitational inhomogeneities in the early Universe. Focusing on sources active on sub-horizon scales, we derive general expressions relating particle production to the unequal-time two-point function of the stress-energy tensor sourcing scalar, vector and tensor metric perturbations. The resulting particle yield probes the time-like support of this correlator, and in the tensor case the same object controls gravitational wave emission when evaluated on the light-like support. This establishes a phenomenological link between dark matter production and gravitational wave signals, allowing the dark matter mass to be related to the amplitude of the
stochastic gravitational wave background. Our results show that, on sub-horizon scales, particle production from inhomogeneous metric backgrounds practically reduces to gravitational scattering. This directly connects the formalism to gravitational freeze-in from the Standard Model thermal bath, while extending it to non-thermal and out of
equilibrium sources. We apply the formalism to first order phase transitions and discuss the associated production from scalar and tensor perturbations. The mechanism can efficiently populate gravitationally coupled dark sectors, especially when the perturbations are generated shortly after inflation.
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Cosmology and Nongalactic Astrophysics
Memoirs of the curvaton: non-perturbative non-Gaussianity and supermassive primordial black holes
S. Allegrini, A. J. Iovino, G. Perna et al. (+1 more)
The curvaton provides a simple mechanism for generating strongly non-Gaussian
curvature perturbations after inflation, with potentially important consequences on small scales. We study curvaton dynamics beyond the standard quadratic potential and construct the local non-Gaussian map $\zeta=F(\zeta_{\rm G})$ relating the
curvature perturbation to an auxiliary Gaussian field $\zeta_{\rm G}$. Curvaton self-interactions make the onset of oscillations field dependent and modify the effective equation of state once the curvaton enters the adiabatic regime. We incorporate these effects using the abbreviated action, which provides a compact way to connect the frozen and oscillatory regimes and exposes sources of non-Gaussianity absent in the purely quadratic case. We apply the formalism to quadratic, monomial, quartic, and cosine potentials, for which we derive the mapping $F(\zeta_{\rm G})$ and show that self-interactions can either enhance or suppress the resulting non-Gaussianity depending on the potential and initial conditions. We consider non-perturbative aspects in the strongly non-Gaussian regime, and show how strong non-Gaussianity can suppress the power spectrum. As an application, we provide a bottom-up scenario in which strongly positive curvaton non-Gaussianity allows
primordial supermassive black hole seeds at peak amplitudes $\mathcal{A}_\textrm{pk}\sim10^{-3}$, which are compatible with the COBE/FIRAS $\mu$-distortion bounds. This opens a new
primordial scenario for the Little Red Dots observed by the JWST. The
axion-like curvaton provides a particularly natural setting for this mechanism.
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All authors S. Allegrini, A. J. Iovino, G. Perna, H. Veermäe
High Energy Astrophysical Phenomena
Accretion-Driven Evolution of Compact-Object Populations in Gas-Rich Environments and the Origin of Massive Gravitational-Wave Sources
Mor Rozner, Alejandra Rosselli-Calderon and Enrico Ramirez-Ruiz
The origin of the most massive gravitational-wave sources remains elusive. We show that gas
accretion can be understood as a transport process in mass space, causing compact objects to migrate through a population at rates determined by the underlying growth law. Using a continuity-equation framework, we demonstrate that population
evolution is governed primarily by the mass dependence of the
accretion rate, $\dot m \propto m^\beta$.
Accretion laws with $\beta>1$ naturally produce divergent
evolution and generate extended high-mass tails, whereas $\beta<1$ leads to convergent
evolution and compresses the population toward a narrower range of masses. We apply this framework to physically motivated
accretion regimes and explore their consequences using analytical calculations and Monte Carlo population models. We show that sustained gas
accretion can substantially broaden compact-object mass distributions, populate the high-mass end of gravitational-wave catalogs, and alter the mass-ratio distribution of compact-object binaries. In particular, collective
accretion within compact binaries drives their mass ratios toward unity. Our results suggest that gaseous environments act as transport media that continuously reshape compact-object populations, providing a natural pathway toward the formation of massive mergers such as GW231123 and the high-mass tails increasingly revealed by gravitational-wave observations.
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Quantum Physics
Composing Quantum Instruments
Robert I. Booth, Dominik Leichtle, Alex Rice et al. (+1 more)
We study the composition of classically-controlled
quantum instruments–the natural
quantum analogue of Markov kernels. Classically, Markov kernels compose by integrating one kernel against another. Defining this composition for
quantum instruments with continuous outcomes requires an integral of
quantum channel-valued functions with respect to a
quantum instrument. We construct this integral in the Heisenberg picture using the Okamura-Ozawa normal extension to a von Neumann tensor product. This integral recovers the expected finite formula, preserves normal complete positivity and subunitality, and provides the multiplication for a monad governing the composition of
quantum instruments. As an immediate consequence, we identify the category of
quantum Markov kernels as the Kleisli category of this monad.
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All authors Robert I. Booth, Dominik Leichtle, Alex Rice, Kim Worrall
Statistical Mechanics
Optimal parameterization of nonequilibrium generalized master equations from discrete-time experimental data
Chih-Wei Joshua Liu, Jérémie Klinger and Grant M. Rotskoff
Kinetic analyses of experiments often require coarse-grained descriptions, but complex systems rarely conform to the widely used modeling assumptions of Markovianity and thermodynamic
equilibrium.
Memory is indeed a general and often inevitable consequence of coarse-graining. Markov state models (MSMs) are a popular choice of coarse-grained description, but require microstate assignments – which are rarely experimentally tunable – to macrostates that minimize
memory. Generalized master equations (GMEs) circumvent this limitation of MSMs by explicitly capturing
memory. However, GMEs are difficult to parameterize and usually formally approximate in the experimentally relevant discrete-time setting. Here we introduce a maximum-likelihood-based procedure to parameterize formally exact, physically feasible, discrete-time generalized master equations from experiments and simulations in and out of
equilibrium. By adapting
algorithms typically used in optimal transport, we construct physical-constraint-satisfying conditional-maximum-likelihood
estimators of both exact Nakajima-Zwanzig
memory kernels and time-convolutionless GME propagators in discrete time. Applying these
estimators to three examples – experimental recordings of Förster-resonance energy-transfer in an ion channel, experimental nanoparticle tracking of a processive molecular motor, and simulated folding of a
benchmark protein domain – we recover kinetic parameters including relaxation rates, irreversibilities, dwell times, and first-passage times. These results establish discrete-time GMEs as a physically and statistically principled alternative to MSMs for kinetic analyses of experimental and simulated biomolecular systems.
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General Relativity and Quantum Cosmology
Generalizing the interacting dilatonic ghost condensate as a dark energy model
Manuel Gonzalez-Espinoza, Ramon Herrera and Johan Casimiro
In this article, we study the
cosmic evolution of a generalized dilatonic ghost condensate field as a dark energy candidate, formulated from a Lagrangian density with two dominant kinetic terms; one linear and one of arbitrary integer $n>2$ in combination with an exponential potential, which interacts with dark matter through a source term. We analyzed three scenarios: the non-interacting situation $Q=0$ and two different interaction models, $Q\propto\rho_m\dot{\phi}$ and $Q\propto \rho_m H$ to describe the
evolution of the present universe. For each interaction $Q$, we perform a detailed phase-space analysis to obtain stability conditions and identify critical points. In all situations, the system reproduces the standard cosmological dynamics and evolves toward late-time dark energy-dominated attractors, with quintessence or phantom features depending on the sign of the coupling parameter $\alpha$ associated with the standard kinetic term. Furthermore, a joint likelihood analysis with
Cosmic Chronometers, PantheonPlus, and DESI observations is performed for two values of power $n$ ($n=3$ and $n=5$) to determine marginalized parameter constraints at the confidence levels of 68$\%$ and 95$\%$ for the different $Q-$models. For the interaction term $Q\propto \dot{\phi}\rho_m$, we find that the direction of the flow of energy depends on the sign of the coupling parameter $\alpha$ associated with the standard kinetic term. However, for the interaction $Q\propto H\,\rho_m$, the direction of the energy flow is independent of the sign of the coupling parameter $\alpha$ and always remains negative, corresponding to an energy transfer from dark matter to dark energy.
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