Field Of Reissner Research Articles

Scalar field in Reissner–Nordström spacetime: Bound state and scattering state (with appendix on eliminating oscillation in partial sum approximation of periodic function)

In this paper, we solve the massive scalar field in the Reissner–Nordström spacetime. The scalar field in the Reissner–Nordström spacetime has both bound states and scattering states. For bound states, we solve the bound-state wave function and the eigenvalue spectrum. For scattering states, we solve the scattering wave function and give an explicit expression for scattering phase shift by the integral equation method. Especially, we introduce the tortoise coordinate for the Reissner–Nordström spacetime. Moreover, in the calculation of scattering cross sections, we encounter a difficulty in partial sum approximation. If the sum of partial waves cannot be performed exactly, one has to turn to the partial sum approximation which approximates a function by the first several terms of the series. However, in the partial sum approximation there exists an incorrect oscillation which cannot be eliminated by keeping more terms. In the appendix we suggest an approach for eliminating such oscillations in the partial sum.

Greybody factor of a scalar field from Reissner\u2013Nordstr\xf6m\u2013de Sitter black hole

In this work we derive a general expression for the greybody factor of non-minimally coupled scalar fields in Reissner–Nordström–de Sitter spacetime in low frequency approximation. Greybody factor as a characteristic of effective potential barrier, will be presented. We discuss the role of cosmological constant both, in the absence as well as in the presence of non-minimal coupling. Considering non-minimal coupling as a mass term, its effect on the greybody factor will be discussed. We also elaborate the significance of the results by giving formulae of differential energy rate and general absorption cross section. The greybody factor gives insight into the spectrum of Hawking radiations.

Stability of the extremal Reissner–Nordström black hole to charged scalar perturbations

The stability of Reissner–Nordström black holes to neutral (gravitational and electromagnetic) perturbations was established almost four decades ago. However, the stability of these charged black holes under charged perturbations has remained an open question due to the well-known phenomena of superradiant scattering: A charged scalar field impinging on a charged Reissner–Nordström black hole can be amplified as it scatters off the hole. If the incident field has a non-zero rest mass, then the mass term effectively works as a mirror, preventing the energy extracted from the hole from escaping to infinity. One may suspect that such superradiant amplification of charged fields in Reissner–Nordström spacetimes may lead to an instability of these charged black holes (in as much the same way that rotating Kerr black holes are unstable under rotating scalar perturbations). However, we show here that, for extremal Reissner–Nordström black holes, the two conditions which are required in order to trigger a possible superradiant instability [namely: (1) the existence of a trapping potential well outside the black hole, and (2) superradiant amplification of the trapped modes] cannot be satisfied simultaneously. Our results thus support the stability of extremal Reissner–Nordström black holes to charged scalar perturbations.

Statistical Entropy of Dirac Field Outside RN Black Hole and Modified Density Equation

Statistical entropy of Dirac field in Reissner–Nordstrom black hole space-time is computed by state density equation corrected by the generalized uncertainty principle to all orders in Planck length and WKB approximation. The result shows that the statistical entropy is proportional to the horizon area but the present result is convergent without any artificial cutoff.

Quasinormal modes of Rarita–Schwinger field in Reissner–Nordström black hole spacetimes

The Newman–Penrose formalism is used to deal with the quasinormal modes (QNMs) of Rarita–Schwinger perturbations outside a Reissner–Nordström black hole. We obtain four kinds of possible expressions of effective potentials, which are proved to be of the same spectra of quasinormal mode frequencies. The quasinormal mode frequencies evaluated by the WKB potential approximation show that, similar to those for Dirac perturbations, the real parts of the frequencies increase with the charge Q and decrease with the mode number n, while the dampings almost keep unchanged as the charge increases.

Entropy of Reissner–Nordstrom–De Sitter Black Hole in Nonthermal Equilibrium**The project supported by Natural Science Foundation of Shanxi Province of China and by Foundation for the Returned Scholar from the Education Commission of Shanxi Province of China

By making use of the method of quantum statistics, we directly derive the partition function of bosonic and fermionic fields in Reissner–Nordstrom–De Sitter black hole and obtain the integral expression of black hole's entropy and the entropy to which the cosmic horizon surface corresponds. It avoids the difficulty in solving the wave equation of various particles. Then via the improved brick-wall method, i.e. the membrane model, we calculate black hole's entropy and cosmic entropy and find out that if we let the integral upper limit and lower limit both tend to the horizon, the entropy of black hole is proportional to the area of horizon and the entropy to which cosmic horizon surface corresponds is proportional to the area of cosmic horizon. In our result, the stripped term and the divergent logarithmic term in the original brick-wall method no longer exist. In the whole process, the physical idea is clear and the calculation is simple. We offer a new simple and direct way for calculating the entropy of different complicated black holes.

Statistical entropy of Reissner–Nordström black hole

Abstract By using the method of quantum statistics, we directly derive the partition function of bosonic and fermionic field in Reissner–Nordstrom black hole. It is the same as the one obtained by solving wave equation approximately. Then via the improved brick-wall method, membrane model, obtain that the entropy of bosonic and fermionic field in black hole is proportional to the area of horizon. In our result, the stripped term and the divergent logarithmic term don't exist any more. The problem that the state density is divergent around the horizon doesn't exist either. We also give the influence factor of the spining degeneracy of various particles on the entropy of black hole. In the whole process, we do not take any approximation. We offer a new simple and direct way of calculating the entropy of different complicated black holes.