From an appropriate expression for the effective action, the Hawking radiation from charged black holes is derived, using only covariant boundary conditions at the event horizon. The connection of our approach with the Unruh vacuum and the recent analysis [1, 2, 3] of Hawking radiation using anomalies is established. Introduction: Hawking radiation arises… (More)
We describe the deformed Poincare-conformal symmetries implying the covariance of the noncommutative space obeying Snyder's algebra. Relativistic particle models invariant under these deformed symmetries are presented. A gauge (reparametri-sation) independent derivation of Snyder's algebra from such models is given. The algebraic transformations relating… (More)
We apply the method of Banerjee and Kulkarni (arXiv:0707.2449, [hep-th]) to provide a derivation of Hawking radiation from the GHS (stringy) blackhole which falls in the class of the most general spherically symmetric blackholes (√ −g = 1) and also the non-extremal D1 − D5 blackhole using only covariant gravitational anomalies. Introduction : Hawking… (More)
Starting from the chiral covariant effective action approach of Banerjee and Kulkarni [Phys. Lett. B 659, 827(2008)], we provide a derivation of the Hawking radiation from a charged black hole in the presence of gravitational back reaction. The modified expressions for charge and energy flux, due to effect of one loop back reaction are obtained.
The basic characteristics of the covariant current < J µ > and the covariant energy-momentum tensor < T µν > in Unruh, Hartle-Hawking and Boulware states are obtained from a chiral effective action. These results are used to justify the covariant boundary condition used in recent approaches [2, 4, 5, 6] of computing the Hawking flux from chiral gauge and… (More)