939 research outputs found
Propagating waves in an extremal black string
We investigate the black string in the context of the string theories. It is
shown that the graviton is the only propagating mode in the (2+1)--dimensional
extremal black string background. Both the dilation and axion turn out to be
non-propagating modes.Comment: Minor corrections, 11 pages in ReVTeX, no figure
Double-Well Potential : The WKB Approximation with Phase Loss and Anharmonicity Effect
We derive a general WKB energy splitting formula in a double-well potential
by incorporating both phase loss and anharmonicity effect in the usual WKB
approximation. A bare application of the phase loss approach to the usual WKB
method gives better results only for large separation between two potential
minima. In the range of substantial tunneling, however, the phase loss approach
with anharmonicity effect considered leads to a great improvement on the
accuracy of the WKB approximation.Comment: 14 pages, revtex, 1 figure, will appear at Phys. Rev.
Thermodynamics and evaporation of the noncommutative black hole
We investigate the thermodynamics of the noncommutative black hole whose
static picture is similar to that of the nonsingular black hole known as the de
Sitter-Schwarzschild black hole. It turns out that the final remnant of
extremal black hole is a thermodynamically stable object. We describe the
evaporation process of this black hole by using the noncommutativity-corrected
Vaidya metric. It is found that there exists a close relationship between
thermodynamic approach and evaporation process.Comment: 16 pages, 6 figures, added references, to appear in JHE
The absence of the Kerr black hole in the Ho\v{r}ava-Lifshitz gravity
We show that the Kerr metric does not exist as a fully rotating black hole
solution to the modified Ho\v{r}ava-Lifshitz (HL) gravity with
and case. We perform it by showing that the Kerr metric does not
satisfy full equations derived from the modified HL gravity.Comment: 35 pages, no figure
Dilaton gravity approach to three dimensional Lifshitz black hole
The z=3 Lifshitz black hole is an exact black hole solution to the new
massive gravity in three dimensions. In order to understand this black hole
clearly, we perform a dimensional reduction to two dimensional dilaton gravity
by utilizing the circular symmetry. Considering the linear dilaton, we find the
same Lifshitz black hole in two dimensions. This implies that all thermodynamic
quantities of the z=3 Lifshitz black hole could be obtained from its
corresponding black hole in two dimensions. As a result, we derive the
temperature, mass, heat capacity, Bekesnstein-Hawking entropy, and free energy.Comment: 13 pages, 1 figure, version to appear in EPJ
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