arXiv subjects

Limei Yuan

Publications and source records attributed to Limei Yuan.

2 recordsLinked to original sources

arXiv2026

Gravitational Lensing Signatures of Hayward-like Black Holes

We examine the gravitational lensing signatures of a Hayward-like regular black hole and its potential observational distinction from a Schwarzschild black hole. In the weak-field limit, the deflection angle includes a small positive correction proportional to $m \ell^2/b^3$, indicating slightly stronger light bending than in Schwarzschild, though the effect remains observationally negligible at large impact parameters. Current galaxy-scale Einstein-ring data, such as from ESO325-G004, cannot yet constrain the regular-core scale $\ell$. In the strong-deflection regime, for Sgr A* and M87*, the asymptotic position $θ_{\infty}$ is identical to Schwarzschild's. Nevertheless, $\ell$ modifies strong-lensing coefficients $\bar a, \bar b$, influencing angular separations s, relative flux ratio $r_\mathrm{mag}$, and time delays $ΔT_{2,1}$. Our predicted values for these observables remain consistent with current data, suggesting that future high-precision measurements of strong-field lensing may distinguish Hayward-like from Schwarzschild black holes.

gr-qc↗

arXiv2026

Distinguish Bardeen-like black holes by Gravitational lensing

We study Bardeen-like regular black holes without Cauchy horizons via gravitational lensing. In the weak field, the deflection angle receives a positive $\ell$-dependent correction, producing a slightly larger Einstein ring. For the galaxy ESO 325-G004, the predicted ring radius is consistent with current observations. In the strong field, for Sgr A* and M87*, the asymptotic position $θ_{\infty}$ remains identical to the Schwarzschild value; however, SDL coefficients are $\ell$-dependent, the angular separation s increases and the relative flux ratio $r_{\mathrm{mag}}$ decreases as $\ell$ increases. Time delays between relativistic images for Sgr A* and M87* also increase mildly with $\ell$. Our calculated values for these observables remain consistent with current observations. Future strong-field measurements of $ΔT_{2,1}$, s, and $r_{\mathrm{mag}}$ may offer a viable test for regular black holes free of Cauchy horizons and may distinguish Bardeen-like from Schwarzschild black holes.

gr-qc↗