The European Physical Journal C

Abstract Black holes in dense astrophysical environments, such as globular clusters or in the vicinity of other massive objects, may possess accelerations. Such acceleration would modulate the characteristics of the quasi-periodic oscillations (QPOs) observed in X-ray black hole binaries. In this paper, we explore the influence of spin-aligned acceleration of a black hole on QPOs observed in X-ra…

Abstract Along the last 10 years, a general relativistic method has been developed to generate analytical expressions for the black hole (BH) parameters in terms of observables, namely the frequency shift of photons emitted by orbiting test particles and their positions on the sky. Applications of the method to astrophysical systems such as Active Galactic Nuclei (AGNs), in particular to megamase…

Abstract We present an exhaustive BRST lagrangian description of partially massless bosonic fields in four-dimensional space. The basic fields are formulated in terms of two-component spin-tensors in (A)dS space where the tracelessness conditions are automatically fulfilled. The mass shell of partially massless fields is reformulated in terms of constraints on Fock space vectors including the sec…

Abstract We present lattice results for $$f_K/f_{\pi }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>f</mml:mi> <mml:mi>K</mml:mi> </mml:msub> <mml:mo>/</mml:mo> <mml:msub> <mml:mi>f</mml:mi> <mml:mi>π</mml:mi> </mml:msub> </mml:mrow> </mml:math> in the iso-symmetric limit of pure QCD (isoQCD) with $$N_f=2+1$$ <mml:math xmlns:mml="http://www.w3.org/1998…

Abstract In this work, we studied the Ayon-Beato Garcia (ABG) solution describing a nonsingular charged black hole using the moving-puncture method. As the first step, we obtained the BG solution in isotropic coordinates with a new, accurate numerical procedure. By focusing on the situation where there is at least one horizon, where the charge is smaller than or equal to a particular critical val…

Abstract In this paper, we update constraints on the Holographic Dark Energy (HDE) model and the Interacting Holographic Dark Energy (IHDE) models in a non-flat universe, building upon our previous work in which the flat HDE and IHDE models were tested using same datasets, including DESI DR2 BAO, the five-year supernovae sample from DES, CMB distance priors, observational Hubble parameter data, a…

Abstract Spin dependent phenomena in inclusive hadron production have been extensively investigated, yet their microscopic origin and universality across different hadrons are still not fully understood. In particular, it is presently unknown whether antiprotons produced in unpolarized hadronic collisions can acquire a transverse polarization as a result of spin dependent $$\bar{p}N$$ <mml:math x…

Abstract We study gravitational quasinormal modes of the Hayward spacetime, a regular black-hole geometry that also admits an interpretation as an effective quantum-corrected solution within asymptotically safe gravity. Using both the higher-order WKB method supplemented with Padé approximants and time-domain integration with Prony analysis, we obtain accurate spectra for axial perturbations and …

Abstract Two-body tunneling problems are hard to treat analytically due to the incompatibility between tunneling and perturbation theory. The lack of classical solutions of the Euclidean Lagrangian of continuous systems further thwarts semiclassical expansions. To develop an analytic theory which provides insight on interacting two-particle tunneling, we use new results to derive the Bethe–Salpet…

Abstract In the era of precision measurements in high-energy heavy-ion physics, there is an increasing expectation towards phenomenological and theoretical studies to provide a better description of data. In recent years, multiple experiments have confirmed through two-pion Bose–Einstein correlation measurements that the shape of the two-pion pair source can be well described by Lévy-stable distr…

Abstract In this paper, we study the observable signatures of Lorentz violation (LV) in low-energy Hořava gravity by simulating the images and polarization features of rotating LV black holes using a backward ray-tracing method. Within a thin-disk accretion model and the ZAMO framework, we numerically solve the geodesics equation of photon and simulated the corresponding thin-disk images and pola…

Abstract We investigate the realization of a nonsingular cosmological bounce in metric f ( R ) gravity using a controlled exponential deformation of the Starobinsky $$R^{2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>R</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:math> model. Adopting a smooth Gaussian-type bouncing scale factor, we first demonstrate a no-go re…

Abstract We carry out an Effective Field Theory (EFT) study of the $$pp \rightarrow \bar{t} t Zh$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>p</mml:mi> <mml:mi>p</mml:mi> <mml:mo>→</mml:mo> <mml:mover> <mml:mrow> <mml:mi>t</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>¯</mml:mo> </mml:mrow> </mml:mover> <mml:mi>t</mml:mi> <mml:mi>Z</mml:mi> <mml:mi>h</mml:mi> </mml:mr…

Abstract We investigate and update observational constraints on cosmological parameters within the $$\Lambda $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>Λ</mml:mi> </mml:math> CDM and dynamical dark energy frameworks, using a new compilation of the transverse (or 2D) BAO data, measurements that provide a relatively model-independent estimate of the BAO angular scale at a …

We present a deep learning pipeline to perform a model-independent, likelihood-free search for anomalous (i.e., non-background) events in the proposed next-generation multi-ton scale liquid xenon-based direct detection experiment, DARWIN. We train an anomaly detector comprising a variational autoencoder (VAE) and a classifier on high-dimensional simulated detector response data and construct a 1D…

Abstract We develop a fully consistent anisotropic extension of the Imran class ICG (Isotropic Compact Gravastar) model within general relativity. A geometry-coupled anisotropy is introduced at the exact equation level, ensuring regularity at the center, smooth matching to the exterior Schwarzschild spacetime, and the absence of thin shells. A controlled option enforces vanishing anisotropy at bo…

Abstract We investigate the dynamics of spinning test particles in the vicinity of Einstein-geometric Proca (EGP) Anti-de Sitter (AdS) compact objects, which arise from metric-Palatini gravity extended by the antisymmetric part of the affine curvature. Using the Mathisson–Papapetrou–Dixon (MPD) equations with the Tulczyjew spin supplementary condition, we derive the effective potential and analyz…

Abstract Cosmogenic muon-induced radioactive isotopes pose a significant background source for deep-underground low-background experiments. Although rock overburdens at underground sites substantially attenuate the cosmogenic muon flux, residual muon-induced backgrounds still require active suppression. For future multi-kiloton liquid scintillator (LS) detectors, such as the Jiangmen Underground …

Abstract We investigate the thermodynamics and phase structure of an extremely rare exact, static and spherically symmetric black hole solution in the Einstein–Skyrme theory. The solution is characterized by two matter-sector couplings: K , which controls the strength of the Skyrme field and induces a solid-angle-deficit-like factor $$1-8\pi K$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/Ma…

Abstract We present the first high-twist study of the proton form factors $$F_{1,2}(Q^2)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>F</mml:mi> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>,</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:msup> <mml:mi>Q</mml:mi> <mml:mn>2</mml:mn> </mml:msup> <mml:mo>)</mml:mo> </mml:m…