Abstract We establish a statistically grounded framework for generalized black hole thermodynamics based on non-extensive statistics. Unlike conventional phenomenological approaches, we explicitly derive a structurally unique generalized Bekenstein–Hawking entropy from the microscopic state counting of a near-horizon photon gas within the framework of Tsallis statistics. This formulation is fully consistent with the first law of black hole thermodynamics and smoothly recovers the standard Bekenstein–Hawking area law in the extensive limit ( q → 1 ). To examine the macroscopic viability of this microscopically grounded entropy, we investigate its implications for Reissner–Nordström black holes. We demonstrate that the entropic deformation governs both local and global thermal stability, thereby generating a rich multi-branched phase structure comprising small, intermediate, and large black holes with Van der Waals-like critical behavior. We further establish an optical-thermodynamic analogy by relating photon-sphere observables, including orbital periods and Lyapunov exponents, to thermodynamic variables. These optical signatures qualitatively track the thermodynamic critical behavior and phase structure, suggesting their potential relevance as observational probes in future high-resolution measurements. Collectively, these results may shed light on a conceptual connection between non-extensive entropy, black-hole critical phenomena, and strong-gravity optics.
Abstract We construct a matrix model for the quantization of a four-dimensional dilaton black hole featuring a geometrically deformed angular sector r 2 R ( r ) 2 , with R ( r ) = ( r / r 0 ) H . By promoting spatial coordinates to N × N Hermitian matrices and deforming the kinetic and commutator terms via the spectral operator R ( R ) , we show that the eigenvalue distribution encodes a quantum geometry that reproduces the classical black hole background in the large- N limit. The thermodynamic entropy scales as S ∼ α ( H ) N 2 log N + β ( H ) N 2 , matching the generalized Bekenstein–Hawking law when G N ∝ 1 / N 2 and r + ∝ N 1 / ( H + 1 ) . We demonstrate that H acts as a physical control parameter driving genuine quantum phase transitions at H c = − 1 / 2 and H c = − 3 / 4 , accompanied by dimensional reduction and non-analytic behavior in the order parameter. The entanglement entropy between matrix subsystems obeys a deformed area law, confirming holographic scaling. Furthermore, we explicitly reconstruct the emergent spacetime metric and verify that it satisfies the deformed Einstein–dilaton field equations. Finally, we prove that in the limit H → 0 , the model reduces exactly to the BFSS matrix theory, whose semi-classical limit yields the Reissner–Nordström–AdS black hole, establishing the framework as a consistent, non-perturbative quantization of deformed gravity.
Abstract Space-based gravitational wave detection imposes extremely stringent requirements on the acceleration noise of test mass (TM), with magnetic effect being one of the significant noise sources. Prior assessments of magnetic effects have only considered the translational acceleration of the center of mass. This work systematically evaluates the disturbing forces and torques produced by magnetic effects on all six degrees of freedom, with particular emphasis on the magnetic torque noise and the resulting force noise coupled into the sensitive axis. Based on the derivation of magnetic potential energy, a finite element calculation method for estimating magnetic torque noise is established, which incorporates the spatial distributions of both the residual magnetic moment and the magnetic susceptibility. The resulting residual acceleration noise along the optical sensitive axis is then calculated, taking into account the crosstalk effects of the center-of-mass to centroid offset, electrostatic coupling, and TM-laser interferometer coupling. This noise lies on the order of 10 − 17 ms − 2 Hz − 1 / 2 @0.1 mHz. The results indicate that the main contribution to magnetic torque noise comes from the coupling between the residual magnetic moment and the spacecraft’s magnetic field, while the contribution from magnetic inhomogeneity accounts for 16%.
Abstract Quarkyonic matter is a state of matter in dense QCD whose bulk thermodynamics is dominated by quarks, while low-energy excitations remain confined. This picture leads to a crossover description from baryonic matter to quark matter, which is triggered by the saturation of quark states in dense matter ( quark saturation ). The crossover driven by the quark saturation accompanies rapid growth in pressure but moderate increase in energy density, resulting in a characteristic peak in the sound speed. Such a rapid stiffening is consistent with constraints inferred from neutron star observations. The quark saturation can occur at a few times nuclear saturation density, which is smaller than the density at which the baryon cores of ∼ 0.5 – 0.8 fm spatially overlap. In this contribution we discuss an ideal model of quarkyonic matter, the IdylliQ model, and we explicitly describe how the baryon and quark occupation probabilities are related, and explain how stiffening of matter occurs. The model is further applied to charge neutral matter including hyperons, and it is shown that the statistical constraints at quark level induce effective repulsion among different baryon species, mitigating the hyperon softening problem in neutron star physics.
Abstract In this work, we derive an exact static, axially symmetric, nonrotating vacuum solution of the Einstein field equations depending on three constant parameters: the throat radius r 0 , a parameter q , which is closely associated with the Komar mass, and a parameter s , which determines the axial/polar structure of the geometry. For s = 0 , the asymptotically flat wormhole sector appears, and the solution reduces to the Gibbons–Volkov ring-wormhole geometry, while the ring conical excess of the extended geometry is removed from the final physical manifold by the cut-and-paste construction. For s ≠ 0 , the solution exhibits a stronger axial singularity instead of a finite axial conical defect. We employ the cut-and-paste construction to generate wormhole geometries from this solution for q ≠ 0 and s = 0 . In addition, we perform a detailed analysis of the embedding diagrams, the wormhole throat, the occurrence and structure of trapped surfaces, the behavior of geodesics, the associated tidal forces, the Petrov algebraic classification, the Newman–Penrose spin coefficients, the energy conditions, and the corresponding invariant conserved charges.
