High Energy Physics (Phenomenology)
A B-factory continuum retune of PYTHIA 8 hadronization parameters using BELLE and BABAR identified-hadron data
Muhammad Ajaz and Haifa I. Alrebdi
We refine the hadronization sector of a pp PYTHIA~8 tune in $e^+e^-\to q\bar q$ production using selected BELLE and BABAR measurements near the $\Upsilon(4S)$ region. The study is performed with PYTHIA~8.316 and Rivet~4.1.1 and is restricted to parameters used in this $e^+e^-$ setup. Starting from the five-parameter hadronization subset of the pp tune, we carry out a staged extension guided by the remaining differences in the BELLE and BABAR data. The final comparison uses a fixed common set of 20,803 bins and samples of 1,000,000 generated events per analysis and tune point. On this basis, the selected refined tune gives a bin-weighted score of 73.42, compared with 76.49 for the Skands $e^+e^-$ reference and 79.22 for Monash~2013 $e^+e^-$. It remains the best-scoring tune for the BELLE charged-
hadron,
baryon, and single- and dihadron measurements, while Skands still performs better for the BABAR charged-
hadron sample and the BELLE
meson sample. The bin-weighted ordering is driven primarily by the BELLE 2020 sample. The refined tune gives a small but stable improvement for the selected BELLE and BABAR measurements, although clear differences between the individual
datasets remain.
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Geophysics
Scenario-conditioned flow matching for probabilistic generation of three-component ground-motion waveforms
Yi Ding, Jinjun Hu, Su Chen et al. (+5 more)
Performance-based seismic risk assessment requires three-component acceleration histories compatible with specified source, path, and site conditions. Conventional ground-motion prediction equations provide scalar intensity measures, while many generative waveform models learn amplitude and waveform shape within a single high-dimensional target. We present WaveFlowGMM, a two-stage probabilistic ground-motion model that uses peak ground acceleration (PGA) as an amplitude interface between scenario conditioning and waveform generation. The amplitude stage uses physics-informed symbolic learning to estimate component-wise PGA medians and a full cross-component covariance. The waveform stage uses few-step AlphaFlow in an invertible wavelet-packet coefficient space to generate normalised three-component histories that are rescaled by sampled PGA. Tests on an event-level NGA-West2 holdout set show that the generated motions recover the main magnitude, distance, and site scaling, keep peak and spectral residuals close to zero, preserve three-component amplitude dependence, and yield velocity and displacement histories without systematic drift after integration of the generated three-component acceleration histories. The framework provides an interpretable and computationally efficient candidate component for waveform-level seismic hazard and risk analysis.
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All authors Yi Ding, Jinjun Hu, Su Chen, Xianwei Liu, Zhongxiang Zhang, Zongchao Li, Xiaojun Li, Lili Xie
Optics
Fundamentals of Optical Fiber Sensing Schemes Based on Coherent Optical Time Domain Reflectometry: Signal Under Dynamic Temperature Conditions
Roman Ermakov, Huwei Wang, Florian Azendorf et al. (+4 more)
We present a theoretical, algorithmic, and experimental study of temperature sensing using $\phi$-OTDR with coherent detection. A physics-based model is developed to relate the measured Rayleigh backscattered signal to temperature variations along the fiber, showing that the phase
evolution encodes the cumulative temperature change between the interrogator and the sensing location, while the amplitude exhibits only local sensitivity. Based on this insight, we propose robust
algorithms for temperature-event detection and temperature-profile reconstruction. Experimental results demonstrate reliable recovery of temperature-induced perturbations in standard single-mode fibers using coherently detected $\phi$-OTDR.
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All authors Roman Ermakov, Huwei Wang, Florian Azendorf, André Sandmann, Juan M. Marin, Francesco Da Ros, Darko Zibar
Instrumentation and Methods for Astrophysics
Combining a Diffraction-Limited Coronagraph with Fiber Nulling: A Demonstration of Serially Coupling Different Nullers
Satoshi Itoh, Taro Matsuo, Reiki Kojima et al. (+3 more)
We present experimental results of an efficient small-IWA ($\sim$1 $\lambda/D$) high contrast imaging approach realized by co-optimizing a coronagraph front-end with a fiber nulling 2nd stage. The setup includes the one-dimensional diffraction-limited coronagraph (1DDLC) and Parity Fiber Nuller (PFN). The 1DDLC has promising features (binary nuller, small inner working angles (IWAs)). Although the 1DDLC has the 2nd/4th-order sensitivity to spectral bandwidth and tilt aberrations, it outputs
stellar leak due to wavelengths other than the design wavelength only as a flat wavefront on the Lyot-stop plane, preserving the same complex amplitude profile as an on-axis point source. The PFN after the 1DDLC erases the leak from the 1DDLC. For the wavelength 6% less than the coronagraph's design-center wavelength, we confirmed the contrast mitigation ability of $3.5\times10^{-5}$, which is about 1/20 times the value of the case with only 1DDLC, suggesting that the combined system works robustly against the broad spectral bandwidth. Future work needs to address the demonstration of the anticipated broadband robustness for the contrast level lower than about $10^{-5}$.
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All authors Satoshi Itoh, Taro Matsuo, Reiki Kojima, Motohide Tamura, Takahiro Sumi, Oliver Guyon
Accelerator Physics
High-Power Polarization-Controlled Attosecond-Scale Soft X-ray Pulses
Zhaoheng Guo, Carlo Vicario, Andre Al Haddad et al. (+18 more)
We demonstrate a versatile platform for high-power attosecond soft X-ray pulse generation with polarization and
photon energy control at the SwissFEL free-electron
laser. An isolated high-current spike embedded within a long electron-beam pedestal emits soft X-ray pulses with single-spike spectra and multi-electronvolt bandwidths in the tunable
magnetic fields of Apple-X undulators. Demonstrated pulse parameters include a
photon energy range of 450–1070 eV, circular as well as linear polarization, and pulse energies from tens to above hundred microjoules. By tuning the longitudinal slice-dependent transverse electron beam orbit we can rapidly switch between attosecond and few femtosecond pulse length. By exploiting
magnetic chicanes in the undulator line we can produce two-colour pulse pairs with tunable delay or increase the pulse energy beyond 200~\textmu J through multi-stage amplification schemes. High-resolution longitudinal phase-space measurements and start-to-end simulations in addition to spectral measurements provide consistent evidence for attosecond-scale pulse durations. This unique combination of high pulse energy and polarization control of attosecond-scale soft X-ray pulses enables the element-specific investigations of
spin and
chiral dynamics on the natural time scale of electron motion.
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All authors Zhaoheng Guo, Carlo Vicario, Andre Al Haddad, Christopher Arrell, Andreas Dax, Umit Demirbas, Nicole Hiller, Martin Huppert, Christoph Kittel, Gregor Knopp, Eduard Prat, Sven Reiche, Antoine Sarracini, Thomas Schietinger, Kirsten Schnorr, Alexandre Trisorio, Didier Voulot, Tobias Weilbach, Hankai Zhang, Christoph Bostedt, Philipp Dijkstal
Chemical Physics
Toward a local manipulation of DNA by quantum fields
Tommaso Cenci, Riccardo Alessandro and Enrico Ronca
Hydrogen bonds are the fundamental backbone for deoxyribo-nucleic acid (DNA) stability. In this letter we propose a new strategy based on plasmonic cavities to perform a local manipulation of hydrogen bonds in DNA. The analysis is performed using state-of-the-art
Quantum Electrodynamics Coupled Cluster calculations (QED-CC). We demonstrate that in standard strong coupling regimes, small but appreciable local modifications of the nucleotide bases' interactions can be induced in a totally non-intrusive manner. The effect can eventually be enhanced if ultra-strong coupling conditions can be reached. Our strategy provides an alternative approach to methodologies based on a collective coupling to perform optical DNA manipulation.
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High Energy Physics (Theory)
Two-scalar-field $f(R)$ Thick Branes, Gravitational Resonances and Quasinormal Modes
Xin-Yi Pan, Heng Guo, Jing-Xin Gong et al. (+1 more)
In this paper, we investigate thick brane worlds in $f(R)$
gravity supported by two-scalar-field. The two-scalar sector provides an analytical warped background with tunable energy-density splitting, allowing us to test whether a Bloch-type internal structure can generate long-lived tensor perturbations resonances in the physically admissible region. We impose the positivity of \(f_R\equiv df/dR\), the derivative of the gravitational Lagrangian with respect to the
Ricci scalar, which plays the role of an effective gravitational coupling in \(f(R)\)
gravity. This separates the smooth ghost-free branch from a singular branch where this effective coupling vanishes. In the ghost-free branch, neither the relative-probability spectrum nor the phase-shift transmission spectrum shows narrow real-axis resonant peaks. These real-axis diagnostics indicate that the internal brane structure alone does not produce long-lived tensor resonances in the ghost-free region. Sharp quasi-localization peaks appear only in the singular branch, where the vanishing effective coupling induces divergent structures in the tensor potential; these peaks should therefore be interpreted as singular-boundary signals rather than ghost-free resonances of the smooth brane background. We then characterize the ghost-free massive Kaluza-Klein modes in the complex-frequency plane. Using the Asymptotic Iteration Method where applicable and time-domain evolutions with a supersymmetric partner potential as a zero-mode filtering tool, we extract the fundamental quasinormal frequencies. The modes have negative imaginary parts and quality factors \(Q\simeq0.9-1.9\), showing that the ghost-free massive tensor excitations are broad, short-lived dissipative modes. Thus the QNM spectrum provides the appropriate complex-frequency description of the Kaluza-Klein dynamics when no narrow real-axis resonances are resolved.
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All authors Xin-Yi Pan, Heng Guo, Jing-Xin Gong, Hong-Tao Jiang
Nuclear Theory
Relativistic magnetohydrodynamics from kinetic theory
Khwahish Kushwah
This thesis develops a kinetic-theory framework for relativistic dissipative magnetohydrodynamics under strong electromagnetic fields, motivated by
quark-
gluon plasma in heavy-ion collisions. Starting from the relativistic Boltzmann-Vlasov equation and using the method of moments within the 14-moment approximation, it derives causal second-order hydrodynamic equations for relativistic
plasmas with increasing generality. The work first review relativistic dissipative hydrodynamics and its kinetic foundations, emphasizing the need for Israel-Stewart-type transient theories to preserve causality and stability. Electromagnetic fields are then introduced at the microscopic level, where the Lorentz force modifies the moment hierarchy and produces anisotropic transport effects absent in field-free fluids. Next, it develops relativistic dissipative magnetohydrodynamics for a non-resistive two-component
plasma of oppositely charged particles. Here, the
magnetic field couples the dissipative sectors of the two species, generating relative dissipative currents and coupled shear dynamics. For Bjorken expansion, the theory predicts damped oscillations in the transverse shear sector associated with cyclotron motion. Finally, the thesis treats the resistive two-component case, where the electric field evolves dynamically and couples to charge
diffusion and shear stress. The resulting theory reveals current-shear feedback, transient electromagnetic generation of momentum anisotropy, and underdamped dissipative oscillations. Applications to homogeneous and Bjorken-expanding
plasmas show how resistive and electromagnetic effects modify
evolution beyond standard hydrodynamics. Overall, the thesis extends relativistic dissipative hydrodynamics to magnetized and resistive
plasmas, providing a microscopic foundation for future studies of strongly magnetized
quark-
gluon plasma and astrophysical systems.
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Cosmology and Nongalactic Astrophysics
Cosmological Viability of Exponential Infrared $f(T)$ Gravity
Mahmoud Hashim, Eleonora Di Valentino, Jackson Levi Said et al. (+1 more)
We investigate the cosmological viability of exponential infrared $f(T)$ teleparallel
gravity using current cosmological observations. This framework realizes late-time
cosmic acceleration through torsional modifications of
gravity without enlarging the six-parameter cosmological parameter space of spatially flat $\Lambda$CDM, and admits two distinct solution branches: a phantom-like model (Model I) and a model featuring a negative-to-positive transition in the effective torsional dark-energy density (Model II). We constrain both branches using CMB observations from Planck, ACT, and SPT together with DESI BAO and Pantheon+ Type Ia
supernovae. We find that the principal branch (Model I) alleviates the Hubble tension relative to $\Lambda$CDM, but remains statistically disfavoured by the combined
dataset. The secondary branch (Model II) is decisively ruled out. We show that the failure of Model II originates from the interplay between background and perturbation constraints: once late-time distance measurements constrain the expansion history, the model becomes overconstrained, forcing correlated shifts in $\Omega_{\rm m}h^2$, $A_s$, $n_s$, and $\tau_{\rm reio}$, degrading the fit to the CMB damping tail and driving the optical depth to unphysical values. Our results demonstrate that perturbation observables provide stringent and complementary tests of teleparallel
gravity beyond the background expansion history.
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All authors Mahmoud Hashim, Eleonora Di Valentino, Jackson Levi Said, Waleed El Hanafy
Quantum Physics
Projection Operator Stochastic Equations for Non-Markovian Quantum Systems Under Continuous Measurement-Based Feedback
H. I. Nurdin
Quantum Markov models have been successfully used to accurately model various physical
quantum systems in fields such as
quantum optics, optomechanics and superconducting
circuits and they provide the basis for (measurement-based)
quantum feedback control. However, the
quantum Markov assumption is a strong one and it is not expected to hold for general
quantum systems of interest. The projection operator approach is one approach that has been developed to model non-Markovian
quantum systems by considering its
embedding in a larger Markovian
quantum system, but mainly in the context of
quantum master equations for the dynamics of the unmonitored reduced
quantum state of a
quantum system. This approach was recently adapted for continuously measured non-Markovian
quantum systems, which enables open-loop control but did not yet consider the presence of feedback of the
stochastic measurement record, deriving non-Markovian SDEs for the
evolution of the projected state of the Markovian
embedding. This paper generalizes these
stochastic equations to the setting of
stochastic feedback based on the continuous-measurement record and shows that the equations take the same form but that previously deterministic terms become
stochastic ones which depend on the measurement record, as would be intuitively expected. The
stochastic equations are obtained for a generalized class of measurements that includes continuous (possibly adaptive) homodyne and
photon counting measurements.
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Quantum Physics
Full-Wave Green's-Function Modeling of Collective Single-Photon Emission in Non-Markovian Open-System QED with Finite-Bandwidth Compensation of Dispersive Interactions
Hyunwoo Choi, Jisang Seo, Junwoo Gim et al. (+3 more)
This work presents a full-wave Green's function framework for modeling collective and coherent single-
photon emission from multiple
quantum emitters embedded in complex electromagnetic structures. Starting from a transverse modal completeness relation of modified Langevin noise formalism, we derive a closed set of coupled equations for population dynamics and frequency-resolved field amplitudes in the single-excitation regime. Since the electromagnetic reservoir is not traced out at the level of the dynamical amplitudes, the emitted single-
photon dynamics can be modeled within the same closed set of equations without Markovian approximation in open and dissipative environments. We demonstrate that finite-bandwidth truncation of the spectral density leads to systematic deviations in coherent dispersive interactions, even when dissipative rates appear converged. To restore causal consistency, we introduce a counter-term compensation scheme that restores the missing dispersive contributions without modifying the retained non-Markovian
memory kernel. To validate the scheme and demonstrate the practicality of the proposed framework, we present numerical examples ranging from
benchmark configurations to a three-dimensional dispersive ring-resonator structure via finite element method. These capabilities provide a practical route for rigorously incorporating full-wave electromagnetic simulations into non-Markovian multi-emitter
quantum electrodynamics, enabling predictive modeling of collective emission, coherent energy exchange, and single-
photon radiation in realistic open structures.
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All authors Hyunwoo Choi, Jisang Seo, Junwoo Gim, Bowoo Jang, Weng C. Chew, Dong-Yeop Na
Mathematical Physics
Non-invertible symmetries and modular invariance in lattice models
Yacine Ikhlef
We consider classical 2d
lattice models with face interactions defined in terms of a fusion category. The
symmetries of such models typically include an
algebra of topological operators sitting on a closed path in the
lattice. In the case when the face interactions obey the Temperley-Lieb (TL) relations, we present a generic
algorithm to determine the decomposition of the transfer-
matrix space of states as a direct sum of simple TL modules. We apply this approach to several examples, and analyse the action of topological operators. As an application, we compute the modular transformation of the irreducible TL characters at primitive roots of unity.
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Astrophysics of Galaxies
Dissecting the Obscured Core of GN20: an Active Galactic Nucleus Outshone by Young Stars
M. Hamed, L. Colina, P. G. Pérez-González et al. (+17 more)
We investigate the relative contributions of
star formation and AGN activity to the total energy budget of GN20, one of the most luminous dusty
star-forming
galaxies known at $z>4$, through spatially resolved spectral energy distribution decomposition. We perform
Bayesian SED fitting with CIGALE on two spatially distinct apertures: the
nuclear core (r=0.14", $\sim$1kpc physical) and the full
galaxy (r=1.4", 9.9 kpc), combining JWST/NIRCam and MIRI broadband imaging, JWST/NIRSpec PRISM IFU pseudo-continuum photometry spanning 42 wavelength bins across rest-frame $0.12$–$1.05\mu$m, and archival HST and millimeter interferometry data from NOEMA and PdBI. The integrated SED is dominated by
stellar-heated
dust, with only a marginal AGN contribution at
galaxy-wide scales ($f_\mathrm{AGN}^\mathrm{int}=0.09\pm0.02$). The
nuclear core, however, requires a significant AGN component ($f_\mathrm{AGN}=0.34\pm0.05$) to account for a mid-infrared excess at rest-frame $\sim$2.5–3.6$\mu$m characteristic of AGN-heated
torus dust. The AGN accounts for $\sim34\%$ of the
nuclear infrared luminosity but only $\sim9\%$ of the total integrated $L_\mathrm{IR}$, explaining its weak signature in integrated diagnostics and its consistency with existing upper limits from Spitzer spectroscopy. The inferred black hole mass places GN20 within the local $M_\mathrm{BH}$–$M_\mathrm{bulge}$ relation at the Eddington limit, and in the overmassive regime at sub-Eddington
accretion rates, suggesting early and rapid black hole assembly concurrent with the dominant starburst. GN20 exemplifies a class of systems where
nuclear-scale SED decomposition, enabled by the angular resolution and infrared sensitivity of JWST, is the only means to uncover a buried AGN overwhelmed by
galaxy-wide
star formation.
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All authors M. Hamed, L. Colina, P. G. Pérez-González, J. Álvarez Márquez, A. Crespo Gómez, L. A. Boogaard, A. Bik, H. Übler, S. E. I. Bosman, A. Alonso-Herrero, M. Perna, S. Arribas, L. Ulivi, M. Annunziatella, L. Costantin, A. Labiano, C.-L. Liao, C. Prieto-Jiménez, P. van der Werf, F. Walter
Quantum Physics
Ferroelectric transmon
M. Donaire and A. Cano
Superconducting
qubits are a leading platform for
quantum computing. However, simultaneously achieving low noise sensitivity to suppress decoherence and sufficient anharmonicity to enable fast gate operations remains a central challenge. Here, we introduce the concept of the ferroelectric transmon (FEmon), in which the Josephson junction is shunted by a ferroelectric, or incipient ferroelectric, capacitor. We show, in particular, that the nonlinear ferroelectric response of the capacitor provides an additional degree of freedom for optimizing
qubit anharmonicity while preserving operation in the charge-noise-insensitive regime.
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General Relativity and Quantum Cosmology
A parametric signal plus noise inference framework for short duration non-Gaussian noise transients
Charlie Hoy, Ruxandra Bondarescu, Andrew Lundgren et al. (+1 more)
Gravitational waves are now routinely detected with ground-based observatories, and, through a process known as
Bayesian inference, their source properties are inferred. However, terrestrial noise artifacts, often referred to as glitches, commonly overlap astrophysical signals. This invalidates a fundamental assumption of gravitational wave analyses: the noise is no longer stationary and Gaussian. As a result, traditional techniques can provide biased inferences in realistic data. One method for mitigating the effect of glitches is to jointly analyse both the signal and noise in a single framework. In this work, we introduce bilby-antiglitch to infer the astrophysical signal properties in non-Gaussian noise. By additionally including a quasi-physical glitch model to describe short duration non-Gaussian noise transients, we show that unlike traditional techniques, we infer the true source properties of simulated signals contaminated with loud glitches. We also show that bilby-antiglitch prevents false violation claims of General Relativity, and validates the exceptional nature of gravitational wave signals in spurious data.
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All authors Charlie Hoy, Ruxandra Bondarescu, Andrew Lundgren, Laura K. Nuttall
General Relativity and Quantum Cosmology
Distance duality relation in symmetric teleparallel gravity
Rocco D'Agostino
In this work, we investigate the distance duality relation (DDR) in symmetric teleparallel theories, where
gravity is mediated by nonmetricity. Starting from the general metric-affine formulation and adopting the geometrical optics approximation, we show that the standard Etherington reciprocity relation remains valid in the presence of nonmetricity when electromagnetism is minimally coupled and the
photon number is conserved. We then extend the analysis to a class of $f(Q)$ theories with a nonminimal coupling between the electromagnetic field and the nonmetricity scalar. We demonstrate that such an interaction modifies the conservation of the
photon number current, leading to a dynamical violation of the DDR. Focusing on a homogeneous and isotropic spacetime background in the coincident gauge, we derive a generalized DDR formula that directly relates observational distance measures to the Hubble expansion rate. Furthermore, we discuss the link between the deviations from Etherington's relation and variations of the effective fine-structure constant. Specific illustrative examples of the coupling function are also analyzed, showing that phenomenologically viable models predict only small deviations from the standard DDR. Our results provide a unified framework to distinguish between the
geometric and dynamical origins of DDR violations, opening new avenues for testing non-Riemannian
gravity with future high-precision astrophysical and cosmological observations.
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Strongly Correlated Electrons
Phonon-induced pseudogap phase in TiSe$_2$
Sotirios Fragkos, Nina Girotto Erhardt, Evgenia Symeonidou et al. (+9 more)
To comprehend
quantum ordered states, such as charge density waves (CDW), in layered transition metal dichalcogenides (TMDCs), it is essential to uncover their underlying normal states. Here, we use time- and angle-resolved extreme ultraviolet photoemission spectroscopy and ab initio electron-
phonon calculations to perform excited state band mapping of three prototypical 1T TMDCs, i.e., TiSe$_2$, HfTe$_2$, and ZrTe$_2$, at room temperature. The results reveal the profound impact of strong electron-
phonon-induced thermal fluctuations on the normal-phase electronic structure. Specifically, in the moderate electron-
phonon coupling regime, as in HfTe$_2$ and ZrTe$_2$, thermal fluctuations only lead to small spectral broadening and band renormalization. In the strongly coupled case, exemplified by TiSe$_2$, we observe soft-
phonon-induced, momentum-dependent suppression of spectral weight, i.e., pseudogaps - extending up to 1 eV above the
Fermi level. Our work establishes the normal phase of TiSe$_2$ as a
phonon-induced pseudogap phase governed by strong CDW fluctuations, thereby uncovering previously missing aspects of the TiSe$_2$ phase diagram, with broader implications for other TMDCs in the strong electron-
phonon coupling regime.
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All authors Sotirios Fragkos, Nina Girotto Erhardt, Evgenia Symeonidou, Hibiki Orio, Dominique Descamps, Stéphane Petit, Polychronis Tsipas, Kai Rossnagel, Jakub Schusser, Athanasios Dimoulas, Samuel Beaulieu, Dino Novko
High Energy Astrophysical Phenomena
Multi-band power color-color diagrams of three black hole X-ray binaries observed with Insight-HXMT
Shao-Feng Liu, Long Ji and Yanan Wang
Power color-color diagrams (PCCDs) provide a useful diagnostic tool for studying the
evolution of outbursts in black hole X-ray binaries. In this paper, we present power color-color diagrams of three sources (MAXI J1348-630, MAXI J1820+070 and Swift J1727.8-1613) observed with Insight-HXMT in a wide energy range of 2-80 keV. We compared the hue regions defined by RXTE, which are associated with different spectral states, with the Insight-HXMT results. We find that, for hard and hard-intermediate states, the trajectories of Insight-HXMT in the power color-color diagrams are generally consistent with those of RXTE. In the soft and soft-intermediate states, weak variability generally prevents robust hue constraints. Nevertheless, a few points in MAXI J1348-630 deviate from the RXTE-defined regions, possibly because of averaged variable power spectra and the presence of a type-A QPO. The trajectories of MAXI J1348-630 and MAXI J1820+070 exhibited roughly consistent patterns over different energy bands, whereas Swift J1727.8-1613 was an exception during its very high state, caused by an additional low-frequency component in the low-energy band. We found that the very high state can be identified through the power color-color diagram, exhibiting a hue similar to that of the hard-intermediate state but not forming a loop pattern. We also investigated the relationship between hue and hardness and found that, although they are generally anti-correlated, they provide consistent timing for the spectral state transitions.
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Geophysics · Cross-listed from cs.LG
Probabilistic Inversion with Flow Matching
Baldur Paulwitz and Stefan Buske
We demonstrate the application of Flow Matching, a technique originating from generative Artificial Intelligence, to probabilistic inversion in geophysical settings, such as seismic Full-Waveform inversion. We adapt the well-established mathematical theory of Flow Matching from generative Artificial Intelligence to the context of probabilistic inversion. We evaluate the approach with two case studies: a simple 2D velocity model to illustrate the general features of the method, and the OpenFWI
dataset to show its capabilities for probabilistic inversion of more complex seismic velocity models.
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High Energy Physics (Phenomenology)
Boosted Higgs-strahlung off a $W$ boson at next-to-next-to-next-to-leading order in QCD
Aude Gehrmann-De Ridder, Alexander Huss, Matteo Marcoli et al. (+5 more)
The production of a boosted
Higgs boson in association with a charged weak ($W$)
boson is a key process to scrutinize the electroweak
symmetry breaking mechanism at
hadron colliders. This reaction constitutes the dominant
Higgs production channel at large transverse momentum, providing unique sensitivity to
Higgs-
boson interactions with other Standard Model particles as well as to physics beyond the Standard Model. In this Letter, we present the first fully differential calculation of this important scattering process at next-to-next-to-next-to-leading order (N$^3$LO) in perturbative
Quantum Chromodynamics (QCD). We find that the N$^3$LO corrections, amounting to approximately $+2\%$ in the boosted regime, generally lie at the edge of or outside the standard scale variation band of the previous perturbative order. The residual dependence of the N$^3$LO prediction on perturbative scales is reduced to below the percent level, marking a milestone for the
Higgs precision program.
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All authors Aude Gehrmann-De Ridder, Alexander Huss, Matteo Marcoli, Pier Francesco Monni, Emanuele Re, Luca Rottoli, Federico Silvetti, Paolo Torrielli
Fluid Dynamics
Lagrangian velocity statistics of homogeneous isotropic turbulence in dilute polymer solutions
Yusuke Koide and Susumu Goto
We conduct direct numerical simulations of homogeneous isotropic
turbulence in dilute
polymer solutions to investigate the Lagrangian velocity statistics. We show how
polymers modulate the power spectral density of the Lagrangian velocity and the Lagrangian integral timescale by varying the Reynolds number, forcing method, and
polymer relaxation time. As the
polymer relaxation time increases, the attenuation of the power spectral density extends successively from high to low frequencies, and the Lagrangian integral timescale increases. To clarify the mechanism underlying the modulation of the Lagrangian velocity statistics, we decompose the Lagrangian velocity into the contributions from
vortices at different length scales. Using this scale-decomposition analysis, we demonstrate that the observed modulation of the Lagrangian velocity statistics results from
polymer-induced suppression of
vortices that proceeds from smaller to larger scales.
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Earth and Planetary Astrophysics
The HST/WFC3 Transmission Spectrum of AU Mic b Part I: An Atmosphere Obscured by Contamination and Systematics
William C. Waalkes, Peter Gao, Elisabeth Newton et al. (+10 more)
Young sub-Neptune progenitors around M
dwarfs offer an excellent opportunity to probe the formation of their abundant, older cousins. At $\sim$20 Myr and only 9.7 pc away, AU Mic b is an ideal candidate for this effort, with its density and observations of escaping hydrogen pointing to a significant
primordial atmosphere. Here we present the 0.8-1.6 $\micron$ transmission spectrum of AU Mic b observed with the Wide Field Camera 3 on the Hubble Space
Telescope (HST). We find that HST experienced unstable scanning during its visits, resulting in a variable PSF that dramatically affects the orbit-to-orbit baseline of the observations. While we were able to somewhat mitigate this problem through spectral binning, the effects cannot be completely eliminated, limiting the precision of our results. Our data is further impacted by the intense
magnetic activity of AU Mic, which introduced significant rotational variability along with spot crossings and the transit light source (TLS) effect into the light curves and spectrum, respectively. Through decomposition of the out-of-transit
stellar SED, we are able to constrain AU Mic's photospheric and spot temperatures to 3891$\pm$37 and 3020$\pm$69 K, respectively, with a spot filling factor of $0.33\pm0.05$. Using
Bayesian atmospheric
retrievals, we show that the spectrum is dominated by the TLS effect with weak atmospheric constraints, with the data preferring a relatively small scale height of $<$185 km to 3$\sigma$. Extrapolation of our retrieved spectra shows that the TLS effect dominates over atmospheric features at optical and infrared wavelengths.
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All authors William C. Waalkes, Peter Gao, Elisabeth Newton, Brett M. Morris, Zachory K. Berta-Thompson, Hannah R. Wakeford, Lili Alderson, Andrew W. Mann, Peter Plavchan, Patrick J. Lowrance, Natasha E. Batalha, Eric D. Lopez, Roxana Lupu
Cosmology and Nongalactic Astrophysics
Galaxy bias renormalization: Two-loop Power Spectrum, One-loop Trispectrum and Bispectrum
Thomas Bakx, Mathias Garny, Henrique Rubira et al. (+1 more)
We present a complete treatment of fifth-order renormalized
galaxy bias at the one- and two-loop level in real space, including gradient corrections to deterministic bias operators at next-to-leading order. We then provide a complete computation of the two-loop power spectrum as well as the one-loop bispectrum and trispectrum of biased tracers, and demonstrate how to jointly model these statistics in a fully renormalized framework. These statistics also require
stochastic renormalization of products of two, three or four operators at coincidence, which we include at leading order in gradients by means of an operator product expansion. We verify that all UV limits of loop integrals are absorbed by the counterterms we consider. Upon solving the resulting renormalization group equations, we find a pronounced scale-dependence of higher-gradient bias coefficients. Since our renormalization prescription is performed manifestly at the operator level, our results can also easily be extended to higher $N$-point functions, higher loop orders and field-level analyses.
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All authors Thomas Bakx, Mathias Garny, Henrique Rubira, Zvonimir Vlah
Quantum Physics
Non-Hermitian Rayleigh-Schrödinger-like Perturbation Theory at Exceptional Point
Wei-Ming Chen and Chia-Yi Ju
We develop a Rayleigh–Schrödinger-like perturbation theory for non-Hermitian
quantum systems at an exceptional point of order $N$. Working in the Jordan basis of the unperturbed
Hamiltonian and employing a Puiseux expansion of the perturbed
eigenvalues and eigenstates, we derive explicit recursion relations for the expansion coefficients. The corrections to the unperturbed
eigenvalue in the Puiseux expansion govern the splitting near the exceptional point; the first two are obtained iteratively in two equivalent forms. One is given in terms of the perturbation
Hamiltonian in the Jordan basis, and the other in terms of the generator that drives the
eigenvalue evolution with respect to the perturbation. The latter constitutes the exceptional-point counterpart of a
geometric perturbation method recently developed for the non-exceptional-point regime. Both representations are verified explicitly for the $N = 2$ and $N = 3$ cases.
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General Relativity and Quantum Cosmology
Fragility of stealth solutions in mimetic gravity
Alireza Allahyari, Clarisse Donio, Mohammad Ali Gorji et al. (+2 more)
We study a broad class of constrained mimetic-type extensions of general relativity with action $S=\int{\rm d}^4x\sqrt{-g}\,\bigl(R/2+\lambda\,C[g,\Psi]+{\cal L}_{\rm m}\bigr)$, where $R$ is the
Ricci scalar, $\lambda$ is a Lagrange multiplier, $C[g,\Psi]$ is a scalar functional of the metric and generic field content $\Psi$ (possibly involving $\Psi$ and its covariant derivatives) and ${\cal L}_{\rm m}$ is the matter Lagrangian. The branch $\bar\lambda\to 0$, with the bar denoting a background value, provides a simple screening-like limit in which the constrained sector decouples, as in cosmological realizations where $\bar\lambda$ is typically nonzero on large scales while locally one expects $\bar\lambda\simeq 0$. On the exactly stealth branch $\bar{\lambda}=0$, the constrained sector drops out of the background dynamics, so, on domains where a background profile $\bar\Psi$ satisfying $\bar C=0$ exists, the theory admits the corresponding general relativity geometries as stealth solutions. As an explicit realization of this mechanism, we consider the scalar field case, where $C=g^{\mu\nu}\partial_\mu\phi\partial_\nu\phi\pm1=0$ becomes a Hamilton-Jacobi equation selecting geodesic congruences; in this setting, we study spherically symmetric solutions and construct a stealth Kerr profile using Carter separability. We then show, at the general level, that the $\bar{\lambda}=0$ branch is perturbatively degenerate with general relativity: the constrained sector contributes to the dynamics only through terms weighted by $\bar\lambda$, which vanish on the stealth branch, while still imposing an infinite hierarchy of constraints on the fluctuations. Consequently, the $\bar\lambda\to0$ limit is generically non-uniform, making the would-be screening perturbatively pathological.
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All authors Alireza Allahyari, Clarisse Donio, Mohammad Ali Gorji, Zahra Gorji, Javad T. Firouzjaee
Mesoscale and Nanoscale Physics
Orientation-tunable correlated Chern insulating states in chiral twisted double bilayer graphene proximitized by WSe2
Jiao Xie, Yongqin Xie, Fanqiang Chen et al. (+9 more)
Moire flat bands in
graphene systems proximitized by transition-metal dichalcogenides (TMDCs) provide a setting where
spin-orbit coupling (SOC) can reshape band
topology. The crystallographic
alignment angle twist angle between TMDC and
graphene layers is predicted to tune the balance of Ising and Rashba SOC, but a combined theoretical and experimental understanding of how twist angle governs the topological character of correlated states has not been systematically established. Here we show that in
chiral-stacked twisted double
bilayer graphene in proximity to WSe2, twist angle between
graphene and WSe2 determines the topological character of correlated Chern
insulators. Continuum model calculations reveal that Ising
spin-orbit coupling dominates at zero twist angle, giving rise to flat bands with finite valley Chern numbers, whereas Rashba coupling dominates at larger twist angle, resulting in topologically trivial bands. Transport measurements at quarter filling confirm this picture: twist angle = 0 deg devices exhibit C = +1 Chern
insulators, consistent with spontaneous isospin polarization, whereas twist angle = 15 degree devices show C = 0 despite exhibiting similar correlated insulating behavior. The sharp contrast establishes crystallographic
alignment as a new tuning knob, complementary to twist angle, displacement field, and carrier density, for engineering correlated topological states in van der Waals
heterostructures.
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All authors Jiao Xie, Yongqin Xie, Fanqiang Chen, Jiliang Yang, Sicheng Chen, Moyu Chen, Kenji Watanabe, Takashi Taniguchi, Shi-Jun Liang, Kemi Xu, Bin Cheng, Feng Miao
Mathematical Physics
Boundaries in the Instantaneous Formulation of Field Theories
Silvester G.A. Borsboom
We study boundary conditions in GiMmsy's covariant and instantaneous formulations of classical field theories and show that the instantaneous state space in the presence of a constant Dirichlet boundary condition is a tangent bundle to the configuration space of fields satisfying said condition. We then study the instantaneous state space when only the velocity of the field is required to vanish at the boundary and show that this results in a sector structure, where each sector is a tangent bundle labeled by the configuration at the boundary. Taking the Legendre transform of this sectored state space yields a sectored phase space with leafwise canonical Poisson structures. We apply this to Yang-Mills theory with spatial boundary conditions and relate our results to flux superselection sectors. The sector-moving gauge transformations are not
Hamiltonian because of the lack of a boundary momentum, prompting us to propose a novel definition of the asymptotic or boundary
symmetry group as the quotient of the boundary-preserving
Hamiltonian transformations by the trivial ones. The physical boundary
symmetry group of electromagnetism is then shown to be a copy of the global gauge group even when all sectors are considered simultaneously. Conditions are discussed under which the same holds for non-Abelian Yang-Mills theory.
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Mesoscale and Nanoscale Physics
Thermal rectification due to phonon confinement in nanoparticles
Alexej D. Semenov, Mariia Sidorova, Alessio Zaccone et al. (+1 more)
We demonstrate that thermal rectification can arise at the contact between two spherical nanoparticles of identical material but different size due to the
geometric confinement of
phonons. This confinement suppresses long-wavelength
phonons differently in differently sized particles and creates a size-dependent gap in the
phonon density of states. This gives rise to direction-dependent heat transport even in perfectly homogeneous materials. We develop an analytical model based on
phonon confinement and
phonon ray-tracing in the Casimir regime and derive expressions for heat fluxes and rectification efficiency as functions of particle sizes and temperatures. The model predicts measurable rectification efficiencies for nanoparticles with radii of a few tens of nanometers, reaching fraction of percent at room temperature and much larger values at low temperatures. The proposed mechanism provides a straightforward and scalable route to thermal rectification in granular nanomaterials without requiring material heterogeneity or strong nonlinearities.
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All authors Alexej D. Semenov, Mariia Sidorova, Alessio Zaccone, Marcel Di Vece
Materials Science
Kinetic Monte Carlo-Ising Machine Optimization for Atomistic Inverse Design of Solid Electrolytes
Ai Koizumi, Tomofumi Tada and Ryo Tamura
Maximizing ionic conductivity remains a fundamental challenge in the atomistic design of solid electrolytes. To this end, we present a framework that combines kinetic Monte Carlo (KMC) and factorization machine with quadratic-optimization annealing (FMQA), an Ising-machine-based black-box optimization
algorithm for large-scale combinatorial optimization. KMC evaluates the ionic conductivity for a given dopant configuration, whereas FMQA iteratively learns a surrogate model from a small configuration-conductivity
dataset and proposes configurations expected to maximize conductivity. To address the severe combinatorial explosion in large KMC simulation
cells, we partition the configuration space for parallel optimization. As a proof of concept, we apply this KMC-FMQA framework to bulk 8 mol % yttria-stabilized zirconia, identifying a dopant configuration with an order-of-magnitude higher conductivity than that of random configurations and the experimentally reported conductivity. Combined with experiments, this framework will enable the determination of microscopic structures from measured conductivity, providing insight into the underlying transport mechanisms.
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General Relativity and Quantum Cosmology
Semiclassical Backreaction of Massive Quantum Fields in the Spacetime of a Global Monopole
Owen Pavel Fernández Piedra
We study the leading semiclassical backreaction of massive scalar, spinor, and vector fields in the spacetime of a pointlike global monopole. Starting from the renormalized stress-energy tensors obtained in the Schwinger–DeWitt approximation, we derive the first-order semiclassical geometry generated by a general conserved diagonal source and then specialize it to fields of
spin $0$, $1/2$, and $1$. The locally fixed
quantum source falls as $r^{-6}$ and induces metric corrections of order $r^{-4}$. The scalar field generically produces distinct temporal and radial metric functions, whereas the spinor and vector fields lead to one-function geometries. We analyze the resulting
curvature correction, the acceleration of static observers, geodesic motion, and the validity domain of the first-order solution. The
quantum backreaction produces a local deformation of the monopole exterior but does not modify its asymptotic solid-angle deficit.
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