68 research outputs found
Canonical Theory of 2+1 Gravity
Recently 2+1 dimensional gravity theory, especially has been
studied extensively. It was shown to be equivalent to the 2+1 Chern-Simon
theory and has been investigated to understand the black hole thermodynamics,
i.e. Hawking temperature and others. The purpose of this report is to
investigate the canonical formalism of the original 2+1 Einstein gravity theory
instead of the Chern-Simon theory. For the spherically symmetric space-time,
local conserved quantities(local mass and angular momentum) are introduced and
using them canonical quantum theory is defined. Constraints are imposed on
state vectors and solved analytically. The strategy to obtain the solution is
followed by our previous work.Comment: 6 pages, talk given at LLWI-2000: From Particles to Universe,
Alberta, 20-26 February 200
Analytic Solutions of The Wheeler-DeWitt Equation in Spherically Symmetric Space-time
We study the quantum theory of the Einstein-Maxwell action with a
cosmological term in the spherically symmetric space-time, and explored quantum
black hole solutions in Reissner-Nordstrom-de Sitter geometry. We succeeded to
obtain analytic solutions to satisfy both the energy and momentum constraints.Comment: LaTeX file, 15 page
Rotating Black Hole Entropy from Two Different Viewpoints
Using the brick-wall method, we study the entropy of Kerr-Newman black hole
from two different viewpoints, a rest observer at infinity and zero angular
momentum observer near horizon. We investigate this with scalar field in the
canonical quantization approach. An observer at infinity can take one of the
two possible frequency ranges; one is with positive frequencies only and the
other is with the whole range including negative frequencies. On the other
hand, a zero angular momentum observer near horizon can take positive
frequencies only. For the observer at infinity the superradiant modes appear in
either choice of the frequency ranges and the two results coincide. For the
zero angular momentum observer superradiant modes do not appear due to absence
of ergoregion. The resulting entropies from the two viewpoints turn out to be
the same.Comment: LaTeX 18 pages, 2 figures, Minor modifications in section 3(ZAMO
Classical and Quantum Solutions and the Problem of Time in Cosmology
We have studied various classical solutions in cosmology. Especially we
have obtained general classical solutions in pure \ cosmology. Even in the
quantum theory, we can solve the Wheeler-DeWitt equation in pure \
cosmology exactly. Comparing these classical and quantum solutions in \
cosmology, we have studied the problem of time in general relativity.Comment: 17 pages, latex, no figure, one reference is correcte
de Broglie-Bohm Interpretation for the Wave Function of Quantum Black Holes
We study the quantum theory of the spherically symmetric black holes. The
theory yields the wave function inside the apparent horizon, where the role of
time and space coordinates is interchanged. The de Broglie-Bohm interpretation
is applied to the wave function and then the trajectory picture on the
minisuperspace is introduced in the quantum as well as the semi-classical
region. Around the horizon large quantum fluctuations on the trajectories of
metrics and appear in our model, where the metrics are functions of
time variable and are expressed as . On the trajectories, the classical relation holds,
and the event horizon U=0 corresponds to the classical apparent horizon on
. In order to investigate the quantum fluctuation near the horizon, we
study a null ray on the dBB trajectory and compare it with the one in the
classical black hole geometry.Comment: 20 pages, Latex, 7 Postscript figure
Scalar field dynamics in warped AdS_3 black hole background
We study the normal modes of a scalar field in the background of a warped
AdS_3 black hole which arises in topologically massive gravity. We discuss the
normal mode spectrum using the brick wall boundary condition. In addition, we
investigate the possibility of a more general boundary condition for the scalar
field.Comment: 7 pages, one figure, revtex4, refs. added and minor modifications in
tex
On the Perturbative Solutions of Bohmian Quantum Gravity
In this paper we have solved the Bohmian equations of quantum gravity,
perturbatively. Solutions up to second order are derived explicitly, but in
principle the method can be used in any order. Some consequences of the
solution are disscused.Comment: 14 Pages, RevTeX. To appear in Phys. Rev.
Normal mode analysis for scalar fields in BTZ black hole background
We analyze the possibility of inequivalent boundary conditions for a scalar
field propagating in the BTZ black hole space-time. We find that for certain
ranges of the black hole parameters, the Klein-Gordon operator admits a
one-parameter family of self-adjoint extensions. For this range, the BTZ
space-time is not quantum mechanically complete. We suggest a physically
motivated method for determining the spectra of the Klein-Gordon operator.Comment: 6 pages, no figure, late
Canonical entropy of three-dimensional BTZ black hole
Recently, Hawking radiation of the black hole has been studied using the
tunnel effect method. It is found that the radiation spectrum of the black hole
is not a strictly pure thermal spectrum. How does the departure from pure
thermal spectrum affect the entropy? This is a very interesting problem. In
this paper, we calculate the partition function by energy spectrum obtained
from tunnel effect. Using the partition function, we compute the black hole
entropy and derive the expression of the black hole entropy after considering
the radiation. And we derive the entropy of charged black hole. In our
calculation, we consider not only the correction to the black hole entropy due
to fluctuation of energy but also the effect of the change of the black hole
charges on entropy. There is no other hypothesis. Our result is more
reasonable.According to the fact that the black hole entropy is not divergent,
we obtain the lower limit of Banados-Teitelboim-Zanelli black hole energy. That
is, the least energy of Banados-Teitelboim-Zanelli black hole, which satisfies
the stationary condition in thermodynamics.Comment: 10 page
Entropy of the Schwarzschild black hole to all orders in the Planck length
Considering corrections to all orders in the Planck length on the quantum
state density from a generalized uncertainty principle (GUP), we calculate the
statistical entropy of the scalar field on the background of the Schwarzschild
black hole without any cutoff. We obtain the entropy of the massive scalar
field proportional to the horizon area.Comment: 13 pages, 1 figure; Minor typos corrected, one reference added;
Accepted for publication in Phys. Lett.
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