Zhongwen Feng

Quantum corrections to the thermodynamics of Schwarzschild–Tangherlini black hole and the generalized uncertainty principle

We investigate the thermodynamics of Schwarzschild–Tangherlini black hole in the context of the generalized uncertainty principle (GUP). The corrections to the Hawking temperature, entropy and the heat capacity are obtained via the modified Hamilton–Jacobi equation. These modifications show that the GUP changes the evolution of the Schwarzschild–Tangherlini black hole. Specially, the GUP effect becomes susceptible when the radius or mass of the black hole approaches the order of Planck scale, it stops radiating and leads to a black hole remnant. Meanwhile, the Planck scale remnant can be confirmed through the analysis of the heat capacity. Those phenomena imply that the GUP may give a way to solve the information paradox. Besides, we also investigate the possibilities to observe the black hole at the Large Hadron Collider (LHC), and the results demonstrate that the black hole cannot be produced in the recent LHC.

Constraining the generalized uncertainty principle with the gravitational wave event GW150914

Abstract In this letter, we show that the dimensionless parameters in the generalized uncertainty principle (GUP) can be constrained by the gravitational wave event GW150914, which was discovered by the LIGO Scientific and Virgo Collaborations. Firstly, according to the Heisenberg uncertainty principle (HUP) and the data of gravitational wave event GW150914, we derive the standard energy–momentum dispersion relation and calculate the difference between the propagation speed of gravitons and the speed of light, i.e., Δυ. Next, using two proposals regarding the GUP, we also generalize our study to the quantum gravity case and obtain the modified speed of gravitons. Finally, based on the modified speed of gravitons and Δυ, the improved upper bounds on the GUP parameters are obtained. The results show that the upper limits of the GUP parameters β 0 and α 0 are 2.3 × 10 60 and 1.8 × 10 20 .

The remnants in Reissner–Nordström–de Sitter quintessence black hole

According to the effects of quantum gravity, we investigated the fermion tunneling from the Reissner–Nordstrom–de Sitter quintessence (RN–dSQ) black hole. The corrected temperature is not only determined by the mass and charge of the black hole, but also depended on the quantum number of the emitted fermion and β, which is a small value representing the effects of quantum gravity. The effects of quantum gravity slowed down the increase of the temperature and led to the remnants of the black hole. We think it is a method to avoid the information loss paradox of black holes.

Strong Gravitational Lensing in the Einstein-Proca Theory

Adopting the strong field limit approach, we investigate the strong gravitational lensing of a spherically symmetric spacetime in the Einstein-Proca theory. With the strong field limit coefficient, three observable quantities are obtained, which are the innermost relativistic image, the deflection angle and the ratio of the flux. Comparing the observable value and the theoretical value of the strong gravitational lensing, we can verify the effectiveness of the strong gravitational lensing model.

Dirac equation of spin particles and tunneling radiation from a Kinnersly black hole

In curved space-time, the Hamilton–Jacobi equation is a semi-classical particle equation of motion, which plays an important role in the research of black hole physics. In this paper, starting from the Dirac equation of spin 1/2 fermions and the Rarita–Schwinger equation of spin 3/2 fermions, respectively, we derive a Hamilton–Jacobi equation for the non-stationary spherically symmetric gravitational field background. Furthermore, the quantum tunneling of a charged spherically symmetric Kinnersly black hole is investigated by using the Hamilton–Jacobi equation. The result shows that the Hamilton–Jacobi equation is helpful to understand the thermodynamic properties and the radiation characteristics of a black hole.

Remnants by fermions' tunneling from a Hořava–Lifshitz black hole

Adopting the Hamilton–Jacobi method, we investigated the tunneling radiation of a deform Hořava–Lifshitz black hole, and the original tunneling rate and Hawking temperature are obtained. Based on the generalized uncertainty principle, recent researches imply that the quantum gravity corrected the Dirac equation exactly. Hence, the corrected Dirac equation can express the tunneling behavior of fermions may be more suitable, and meanwhile, the corrected Hawking temperature of the Hořava–Lifshitz black hole is obtained. Comparing with previous results, we find that the Hawking temperature is not only related to the mass of black hole, but also related to the mass and energy of outgoing fermions. Finally, we inferred that the Hawking radiation would stop by the reason of the quantum gravity, and the remnant of the black hole exists naturally, also the singularity of the black hole is avoided.

Modified tunneling radiation of the scalar particles and Dirac particles from a five-dimensional black hole

Incorporating the generalized uncertainty principle (GUP) into the tunneling mechanism, we have studied the tunneling radiation of the scalar particles and fermions from the five-dimensional Schwarzschild–Tangherlini black hole. The results showed that the GUP corrected temperatures do not only depend on the mass of ST black hole, but are also affected by the gravity effects correction β. Besides, the β slows down the Hawking temperature increasing and causes the existence of remnants in black hole evaporation.

Strong Gravitational Lensing in a Brane-World Black Hole

Adopting the strong field limit approach, we investigated the strong gravitational lensing in a Brane-World black hole, which means that the strong field limit coefficients and the deflection angle in this gravitational field are obtained. With this result, it can be said with certainly that the strong gravitational lensing is related to the metric of gravitational fields closely, the cosmology parameter α and the dark matter parameter β come from the Brane-World black hole exerts a great influence on it. Comparing with the Schwarzschild-AdS spacetime and the Schwarzschild-XCMD spacetime, the parameters α, β of black holes have the similar effects on the gravitational lensing. In some way, we infer that the real gravitational fields in our universe can be described by this metric, so the results of the strong gravitational lensing in this spacetime will be more reasonable for us to observe. Finally, it has to be noticed that the influence which the parameters α, β exerted on the main observable quantities of this gravitational field is discussed.