arXiv subjects

Yizhi Liang

Publications and source records attributed to Yizhi Liang.

3 recordsLinked to original sources

arXiv2026

Finite Coherence in Gravitational Waves from Tidally Excited Axion Clouds

Axion clouds around rotating black holes form gravitational atoms whose tidal transitions can radiate gravitational waves in binaries. For strongly coupled Bohr crossings, transition radiation is governed by the outgoing two-level coherence, not by the transition probability alone. This coherence is suppressed both on the adiabatic branch and in the weak passage limit, but survives for intermediate sweep rates, producing a finite transition waveform and a localized orbital response. In more massive systems, fine and hyperfine transitions produce narrowband gravitational radiation and cumulative departures from vacuum binary waveforms. Coherent tidal crossings offer a gravitational-wave probe of axion-cloud dynamics.

gr-qc↗

arXiv2025

Black holes in $f(R,T)$ gravity coupled with Euler-Heisenberg electrodynamics

We investigate the scenario of black holes coupled with the Euler-Heisenberg nonlinear electromagnetic field in the framework of $f(R,T)$ gravity. The black hole solutions for electrically charged, magnetically charged and the dyonic case are separately analyzed, and we discuss the scalar curvature and the energy conditions of the black hole spacetime. In the magnetic charge solution, the $f(R,T)$ correction appears in the $1/r^6$ Euler-Heisenberg electromagnetic field correction term, while the electrically charged black hole solution exhibits an $r^2$ term in the metric function, corresponding to an effective cosmological constant $Λ_\text{eff} = β/(3π)$, inducing asymptotically anti-de Sitter or de Sitter spacetimes depending on the sign of the coupling parameter $β$. The dyonic solution is obtained through vacuum polarization quantum electrodynamics corrections, where electromagnetic duality is broken and the solution contains higher-order correction terms. The relationship between the event horizon and charge of dyonic extreme black holes is studied. Furthermore, we investigate the effective metric, photon trajectories, and innermost stable circular orbit under nonlinear electromagnetic effects, providing images of photon geodesic for varying electric and magnetic charge strengths and $f(R,T)$ coupling parameter.

gr-qc↗

arXiv2025

Lyapunov exponents and phase transition of charged Ads black hole in quintessence

This study investigates the phase transitions of RN-AdS black holes immersed in a quintessence field, employing Lyapunov exponents as a dynamical probe to characterize the thermodynamics of black hole. Incorporating quintessence dark energy into the RN-AdS framework, we find that the Lyapunov exponents for null and timelike geodesics display diminished chaotic behavior with increasing normalization factor of the quintessence field. This feature introduces a finite cutoff to the Lyapunov exponent of unstable circular photon orbits, setting it apart from RN-AdS black hole. At phase transition points, both the free energy and Lyapunov exponents display multivalued branches, reflecting the coexistence of distinct black hole phases. Furthermore, the discontinuity in the Lyapunov exponent can serve as an order parameter with a critical exponent of $1/2$ near the critical point, consistent with the thermodynamic criticality of van der Waals fluids.. These work suggest that Lyapunov exponents provide a framework for probing the thermodynamics of black holes.

gr-qc↗