2 research outputs found
Gravitational anomalies: a recipe for Hawking radiation
We explore the method of Robinson and Wilczek for deriving the Hawking
temperature of a black hole. In this method, the Hawking radiation restores
general covariance in an effective theory of near-horizon physics which
otherwise exhibits a gravitational anomaly at the quantum level. The method has
been shown to work for broad classes of black holes in arbitrary spacetime
dimensions. These include static black holes, accreting or evaporating black
holes, charged black holes, rotating black holes, and even black rings. In the
case of charged and rotating black holes, the expected super-radiant current is
also reproduced.Comment: 7 pages; This essay received an "Honorable Mention" in the 2007 Essay
Competition of the Gravity Research Foundation; (v2) Short comments and
references added; (v3) Minor revisions and updated references to agree with
published versio
Anomalies and Hawking radiation from the Reissner-Nordstr\"om black hole with a global monopole
We extend the work by S. Iso, H. Umetsu and F. Wilczek [Phys. Rev. Lett. 96
(2006) 151302] to derive the Hawking flux via gauge and gravitational anomalies
of a most general two-dimensional non-extremal black hole space-time with the
determinant of its diagonal metric differing from the unity () and use it to investigate Hawking radiation from the Reissner-Nordstrom
black hole with a global monopole by requiring the cancellation of anomalies at
the horizon. It is shown that the compensating energy momentum and gauge fluxes
required to cancel gravitational and gauge anomalies at the horizon are
precisely equivalent to the -dimensional thermal fluxes associated with
Hawking radiation emanating from the horizon at the Hawking temperature. These
fluxes are universally determined by the value of anomalies at the horizon.Comment: 18 pages, 0 figure. 1 footnote and 4 new reference adde