Distinct MLT asymmetry of auroral kilometric radiation observed by the FAST satellite

Auroral Kilometric Radiation(AKR)is a common radio emission,which can contribute to the magnetosphere−ionosphere−atmosphere coupling.Similar emissions have been observed in all magnetic planet magnetospheres of the solar system.In this study,using observations from the FAST satellite from 30 August 1996 to 9 September 2001,the distribution of AKR in altitude=500−4500 km and invariant latitude(|ILAT|)=60°−80°has been analyzed.63045 AKR samples have been identified with~48%(52%)samples on the dayside(nightside).Of considerable interest,there is a distinct MLT asymmetry with the high occurrence rate in MLT=05−08 and 18−22(02−05 and 12−17)in the northern(southern)hemisphere.The distinct MLT asymmetry is associated with the direction of Bxof the interplanetary magnetic field.In addition,the occurrence rate on the nightside clearly increases as the index increases.This study further enriches theAE.information and understanding of AKR in the magnetosphere as well as other similar radio emissions.

Hawking radiation from the Schwarzschild black hole with a global monopole via gravitational anomaly

This paper derives the Hawking flux from the Schwarzschild black hole with a global monopole by using Robinson and Wilczek＇s method. Adopting a dimensional reduction technique, it can describe the effective quantum field in the （3 ＋ 1）-dimensional global monopole background by an infinite collection of the （1 ＋ 1）-dimensional massless fields if neglecting the ingoing modes near the horizon, where the gravitational anomaly can be cancelled by the （1 ＋ 1）- dimensional black body radiation at the Hawking temperature.

Hawking Radiation of Charged Particles in Reissner-Nordstrm Black Hole

We extend the method that Banerjee and Majhi have used to discuss Hawking radiation. Under the condition that the total energy and electrical charge of spacetime are conserved, we investigate Hawking radiation of the charged black hole by a new Tortoise coordinate transformation. Taking the reaction of the radiation of the particle to the spacetime into consideration, we not only derive the radiation spectrum that satisfies the unitary principle in quantum mechanics but also show that the contribution of ingoing particles is equal to the one of outgoing particles on the similar chemical potential term in radiation spectrum caused by charged particles.

Correction to Hawking Tunneling Radiation from Global Monopole Charged BlackHole

Considering the self-gravitation and energy conservation as well as charge conservation, we extend Medved and Vagenas＇s quantum tunneling method to the global monopole charged black hole, and give a correction to Hawking radiation of a charged particle.

Unthermal Hawking Radiation from a General Stationary Black Hole

Using Damour-Ruflini＇s method, Hawking radiation from a general stationary black hole is investigated again deeply. Considering the back reaction of the particle to the space-time and energy conservation, we find that the radiation is not exactly thermal and can take out information from the black hole. This can be used to explain the information loss paradox, and the result is consistent with the works finished before.

Hawking radiation from gravity’s rainbow via gravitational anomaly

Based on the anomaly cancellation method, initiated by Robinson and Wilczek, we investigates Hawking radiation from the modified Schwarzschild black hole from gravity＇s rainbow from the anomaly point of view. Unlike the general Schwarzschild space-time, the metric of this black hole depends on the energies of probes. The obtained result shows to restore the underlying general covariance at the quantum level in the effective field, the covariant compensating flux of energy-momentum tensor, which is related to the energies of the probes, should precisely equal to that of a （1 ＋ 1）-dimensional blackbody at the Hawking temperature.

Hawking radiation via tunnelling from general stationary axisymmetric black holes

Hawking radiation is viewed as a tunnelling process. In this way the emission rates of massless particles and massive particles tunnelling across the event horizon of general stationary axisymmetric black holes are calculated, separately. The emission spectra of these two different kinds of outgoing particles have the same functional form and both are consistent with an underlying unitary theory.

Hawking Radiation from a Non-static Black Hole

A method exactly determining an event horizon and its temperature in a nonstatic space-time is proposed.Using the generalised Tortoise coordinate,we give exact location of event horison and exact Hawking temperature for a general spherically symmetric evaporating black hole.

Hawking effect and quantum nonthermal radiation of an arbitrarily accelerating charged black hole using a new tortoise coordinate transformation

Using a new tortoise coordinate transformation, this paper investigates the Hawking effect from an arbitrarily accelerating charged black hole by the improved Damour-Ruffini method. After the tortoise coordinate transformation, the Klein-Gordon equation can be written as the standard form at the event horizon. Then extending the outgoing wave from outside to inside of the horizon analytically, the surface gravity and Hawking temperature can be obtained automatically. It is found that the Hawking temperatures of different points on the surface are different. The quantum nonthermal radiation characteristics of a black hole near the event horizon is also discussed by studying the Hamilton-Jacobi equation in curved spacetime and the maximum overlap of the positive and negative energy levels near the event horizon is given. There is a dimensional problem in the standard tortoise coordinate and the present results may be more reasonable.

Hawking radiation as tunnelling from arbitrarily dimensional Reissner-Nordstrom de Sitter black hole

This paper extends Parikh-Wilzcek＇s recent work, which treats the Hawking radiation as a semi-classical tunnelling process from the event horizon of four dimensional Schwarzshild and Reissner-Nordstrom black holes, to that of arbitrarily dimensional Reissner-Nordstrom de Sitter black hole. The result shows that the tunnelling rate is related to the change of Bekenstein-Hawking entropy and the factually radiant spectrum is no longer precisely thermal after taking the dynamical black hole background and energy conservation into account, but is consistent with the underlying unitary theory and then satisfies the first law of the black hole thermodynamics. Meanwhile, in Parikh-Wilzcek＇s framework, this paper points out that the information conservation is only suitable for the reversible process but in highly unstable evaporating black hole （irreversible process） the information loss is possible.

Hawking Radiation to An Observer with Variable Acceleration

There exists an event horizon and thermal radiation depending on time to a non-uniformly accelerating observer.The Hawking temperature is proportional to its instantaneous acceleration.

Hawking radiation from Kerr-Newman de Sitter black hole via anomalies

In this paper, Hawking radiation from the Kerr Newman de Sitter black hole is studied via gauge anomaly and gravitational anomaly. The obtained results of Hawking radiation from the event horizon and the cosmological horizon accord with those by other methods.

Covariant Anomaly and Hawking Radiation from Kerr-Newman Black Hole in Dragging Coordinates Frame

In the light of Robinson and Wilczek's new idea,and motivated by Banerjee and Kulkarni's simplified method of using only the covariant anomaly to derive Hawking radiation from a black hole,we generally extend the work to Kerr-Newman black hole in dragging coordinates frame.It is shown that the flows introduced to cancel the anomaly at the event horizon are equal to the corresponding Hawking radiation in dragging coordinates frame,which supports and extends Robinson and Wilczek's opinion.

Hawking radiation from the charged and magnetized BTZ black hole via covariant anomaly

This paper discusses Hawking radiation from the charged and magnetized Bafiados-Teitelboim-Zanelli （BTZ） black hole from the viewpoint of anomaly, initiated by Robinson and Wilczek recently. It reconstructs the electromagnetic field tensor and the Lagrangian of the field corresponding to the source with electric and magnetic charges to redefine an equivalent charge and gauge potential. It employs the covariant anomaly cancellation method to determine the compensating fluxes of charge flow and energy-momentum tensor, which are shown to match with those of the 2- dimensional blackbody radiation at the Hawking temperature exactly.

Hawking Radiation from Horizons of Reissner-Nordstrm de Sitter Black Hole with a Global Monopole via Anomalies

Hawking radiation from cosmological horizon and event horizon of the Reissner-Nordstrom de Sitter black hole with a global monopole is studied via a new method that was propounded by Robinson and Wilzek and elaborated by Banerjee and Kulkarni. The results show that the gauge current and energy-momentum tensor fluxes, which required keeping gauge covariance and general coordinate invariance at the quantum level in the effective field theory, are exactly equivalent to those of Hawking radiation from the event horizon and the cosmological horizon, respectively.

Non-equilibrium Landauer transport model for Hawking radiation from a Reissner-Nordstrom black hole

The recent work of Nation et al., in which the Hawking radiation energy and entropy flow from a black hole is considered to be produced in a one-dimensional Landauer transport process, is extended to the case of a Reissner- Nordstrom black hole. The energy flow contains not only the contribution of the thermal flux but also that of the particle flux. It is found that the charge can also be transported via the one-dimensional quantum tunnel. Because of the existence of the electrostatic potential, the entropy production rate is shown to be smaller than that of the Schwarzschild black hole.

Hawking radiation of stationary and non-stationary Kerr–de Sitter black holes

Hawking radiation of the stationary Kerr–de Sitter black hole is investigated using the relativistic Hamilton–Jacobi method. Meanwhile, extending this work to a non-stationary black hole using Dirac equations and generalized tortoise coordinate transformation, we derived the locations, the temperature of the thermal radiation as well as the maximum energy of the non-thermal radiation. It is found that the surface gravity and the Hawking temperature depend on both time and different angles. An extra coupling effect is obtained in the thermal radiation spectrum of Dirac particles which is absent from thermal radiation of scalar particles. Further, the chemical potential derived from the thermal radiation spectrum of scalar particle has been found to be equal to the highest energy of the negative energy state of the scalar particle in the non-thermal radiation for the Kerr–de Sitter black hole. It is also shown that for stationary black hole space time, these two different methods give the same Hawking radiation temperature.

Hawking Radiation from Plane Symmetric Black Hole Covariant Anomaly

Based on the covariant anomaly cancellation method, which is believed to be more refined than the initial approach of Robinson and Wilczek, we discuss Hawking radiation from the plane symmetric black hole. The result shows that Hawking radiation from the non-spherical symmetric black holes also can be derived from the viewpoint of anomaly.

Hawking radiation from Kerr-Newman-Kasuya black hole via quantum anomalies

We have studied the Hawking radiation of the Kerr-Newman-Kasuya black hole via gauge and gravitational anomaly in the dragging coordinates. The fluxes of the electromagnetic current and the energy momentum tensor for each partial wave in two-dimensional field are obtained.

Hawking Radiation from Spherically Symmetrical Gravitational Collapse to an Extremal R-N Black Hole for a Charged Scalar Field

Si-Jie Gao has recently investigated Hawking radiation from spherically symmetrical gravitational collapse to an extremal R-N black hole for a real scalar field. Especially he estimated the upper bound for the expected number of particles in any wave packet belonging to spontaneously produced from the state , which confirms the traditional belief that extremal black holes do not radiate particles. Making some modifications, we demonstrate that the analysis can go through for a charged scalar field.