114 research outputs found
Hawking Radiation as Tunneling: the D-dimensional rotating case
The tunneling method for the Hawking radiation is revisited and applied to
the dimensional rotating case. Emphasis is given to covariance of results.
Certain ambiguities afflicting the procedure are resolved.Comment: Talk delivered at the Seventh International Workshop Quantum Field
Theory under the influence of External Conditions, QFEXT'05, september
05,Barcelona, Spain. To appear in Journal of Phys.
On the semiclassical treatment of Hawking radiation
In the context of the semiclassical treatment of Hawking radiation we prove
the universality of the reduced canonical momentum for the system of a massive
shell self gravitating in a spherical gravitational field within the Painlev\'e
family of gauges. We show that one can construct modes which are regular on the
horizon both by considering as hamiltonian the exterior boundary term and by
using as hamiltonian the interior boundary term. The late time expansion is
given in both approaches and their time Fourier expansion computed to reproduce
the self reaction correction to the Hawking spectrum.Comment: 18 pages, LaTeX, Corrected typo
Local temperature for dynamical black holes
A local Hawking temperature was recently derived for any future outer
trapping horizon in spherical symmetry, using a Hamilton-Jacobi tunneling
method, and is given by a dynamical surface gravity as defined geometrically.
Descriptions are given of the operational meaning of the temperature, in terms
of what observers measure, and its relation to the usual Hawking temperature
for static black holes. Implications for the final fate of an evaporating black
hole are discussed.Comment: 7 pages, contribution to Proceedings of ERE200
On the Hawking radiation as tunneling for a class of dynamical black holes
The instability against emission of massless particles by the trapping
horizon of an evolving black hole is analyzed with the use of the
Hamilton-Jacobi method. The method automatically selects one special expression
for the surface gravity of a changing horizon. Indeed, the strength of the
horizon singularity turns out to be governed by the surface gravity as was
defined a decade ago by Hayward using Kodama's theory of spherically symmetric
gravitational fields. The theory also applies to point masses embedded in an
expanding universe, were the surface gravity is still related to Kodama-Hayward
theory. As a bonus of the tunneling method, we gain the insight that the
surface gravity still defines a temperature parameter as long as the evolution
is sufficiently slow that the black hole pass through a sequence of
quasi-equilibrium states.Comment: added references for section 1, corrected typos, some improvement in
notatio
Hawking Radiation as Tunneling for Extremal and Rotating Black Holes
The issue concerning semi-classical methods recently developed in deriving
the conditions for Hawking radiation as tunneling, is revisited and applied
also to rotating black hole solutions as well as to the extremal cases. It is
noticed how the tunneling method fixes the temperature of extremal black hole
to be zero, unlike the Euclidean regularity method that allows an arbitrary
compactification period. A comparison with other approaches is presented.Comment: 17 pages, Latex document, typos corrected, four more references,
improved discussion in section
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