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Bing-Bing Chen

Publications and source records attributed to Bing-Bing Chen.

6 recordsLinked to original sources

Shadows and Polarimetric Signatures of Rotating Simpson-Visser Black Holes with Thick Disk Illumination

In this manuscript, we investigate the shadow and polarization images of a Simpson-Visser rotating black hole surrounded by a ballistic approximation accretion flow model. Solving the numerically geodesic and radiative transfer equations, we discuss the influence of the regularization parameter $g$, spin parameter $a$, and observer inclination angle $θ_o$ on the resulting images at $230\,\mathrm{GHz}$ with an infalling motion. The results interpret that, a bright circular ring corresponding to higher-order images is observed, accompanied by an inner region of decreased intensity. Both $g$ and $a$ has little influence on the size of the higher-order images, but significantly changes their shape and intensity distribution. Whereas, variation in $θ_o$ modify the image morphology, producing a crescent-shaped bright region on the left side. Finally, the polarization patterns trace the brightness distribution and vary with both $g$ and $a$, reflecting the spacetime structure. These results demonstrates that the intensity and polarization in thick disk models provide probes of Simpson-Visser rotating black holes and near-horizon accretion physics.

gr-qc

Particle decay and energy conservation in the Kerr-Newman black hole

In this paper, we study the decay of a particle in Kerr--Newman spacetime. Both theoretical analysis and numerical simulations show that when a particle splits in Kerr--Newman spacetime, its mass is inevitably reduced, and this mass deficit is transformed into kinetic energy in the center-of-mass frame. We denote the parent particle as $O$ and the daughter particles as $A$ and $B$. We also find that as the charge parameter $Q$ increases, the specific angular momenta of the parent particle $O$ and the daughter particle $B$ become smaller, the masses of the two daughter particles become larger, the absolute values of their specific energies become smaller, the relative Lorentz factors among the three particles become smaller, and their four-velocities also become smaller. These trends are opposite to those observed when increasing the cosmological constant in Kerr--de Sitter spacetime.

gr-qc

Horizon-scale intensity and polarization images of rotating Konoplya-Zhidenko black holes with thick accretion flows

We investigate the shadow and polarization images of a Konoplya-Zhidenko rotating non-Kerr black hole surrounded by a geometrically thick and optically thin accretion flow. The accretion flow is described by an analytical ballistic approximation accretion flow model. The numerical results show that the shadow image exhibits two main features, an outer bright ring and an inner dark region. The former corresponds to higher order images, while the latter is produced by the black hole event horizon. Increasing the deformation parameter $η$ does not significantly change the overall shape of the higher order images, but it enlarges their size. Increasing the spin parameter $a$ and the observer inclination angle $θ_o$ enhances the asymmetry of the higher order images and makes the intensity on the left side much larger than that on the right side. This behavior is associated with frame dragging and the relativistic Doppler effect. In the polarization images, the degree of linear polarization is much smaller in the higher-order image region than in other regions, and the polarization vectors extend over the whole image plane. These results indicate that the thick disk model produces features in both intensity and polarization images that differ markedly from those in thin disk models. Within the framework used in this work, the observed intensity and polarization signatures can serve as effective probes of the underlying spacetime geometry and near horizon accretion dynamics.

gr-qc

Unveiling Inner Shadows and Polarization Signatures of Rotating Einstein-Gauss-Bonnet Black Holes

Based on the backward ray-tracing method, this paper numerically investigates the shadow and polarization images of rotating Einstein-Gauss-Bonnet (EGB) black hole within the framework of a thin disk model. We systematically analyze the effects of the main model parameters and the observation inclination angle $θ_o$ on both types of images. The results show that, as an intrinsic property of the black hole, the inner shadow undergoes significant deformation with increasing $θ_o$. The increase of the GB coupling constant $ξ$ only reduces the size of the inner shadow, while the spin parameter a does not alter its size but also its shape. And, the photon ring is more sensitive to variations in $θ_o$, while it is less affected by $ξ$ and $a$. For polarization images, the influence of $ξ$ on the polarization intensity is generally consistent with that observed in the accretion disk images. However, the polarization direction near the region of the inner shadow and photon ring changes significantly with $ξ$. This feature can provide an additional and effective observational tool for extracting information about the spacetime structure in Einstein-Gauss-Bonnet (EGB) gravity. Finally, we conclude that, compared to previous reliance on either accretion disk or polarization images alone, the simultaneous combination and synergistic analysis of both can more profoundly reveal the optical properties of rotating EGB black holes, providing a stronger theoretical basis for identifying such black holes through future high-resolution observations.

gr-qc

Testing thermodynamic laws and weak cosmic censorship conjecture of conformal anomaly corrected AdS black hole

By dropping particles into black hole, we have employed the recently new assumption [1] that the change of the black hole mass(enthalpy) should be the same amount as the energy of an infalling particle($ω= dM$), to carefully test the laws of thermodynamics and the weak cosmic censorship conjecture of a conformal anomaly corrected AdS black hole in different phase spaces. Using the energy-momentum relation, the result shows that the first law, second law and weak cosmic censorship conjecture of black hole are all valid in the normal phase space, no violations occur. In the extended phase space, it firstly shows that the first law of black hole thermodynamics is always true in our case. Then, we interestingly find that if the condition ${d\ell} > -\left(P^r \ell^3\right)/{r_+^3}$ satisfied the variation of entropy is always positive, which means there would be no violation of the second law in the extend phase spaces. Also, it is true that there are always horizons by which the singularity is also covered. So, the configurations of the extremal and near-extremal black holes will not be changed, and there has no violation of the weak cosmic censorship conjecture. Finally, all of those conclusions are independent of the scalar curvature parameter $k$ and the conformal anomaly parameter $\tildeα$

gr-qc

Lorentz Violation, Quantum Tunneling and Information Conservation

In this paper, by introducing a Lorentz-invariance-violation (LIV) class of dispersion relations (DR) suppressed by the second power $(E/E_{QG})^2$, we have investigated the effect of LIV on the Hawking radiation of the charged Dirac particle via tunneling from a Reissner-Nordström(RN) black hole. We first find the effect of LIV speeds up the black hole evaporation, leaving the induced Hawking temperature very sensitive to the changes in the energy of the radiation particle, but at the same energy level, insensitive to the changes in the charge of the radiation particle. This provides a phenomenological evidence for the LIV-DR as a candidate for describing the effect of quantum gravity. Then, when the effect of LIV is included, we find the statistical correlations with the Planck-scale corrections between the successive emissions can leak out the information through the radiation. And, it turns out that the black hole radiation as tunneling is an entropy conservation process, and no information loss occurs during the radiation, where the interpretation for the entropy of black hole is addressed. Finally, we conclude that black hole evaporation is still an unitary process in the context of quantum gravity.

gr-qc