37,309 research outputs found
Gravitational Localization of All Local Fields on the Brane
We present a new -brane solution to Einstein's equations in a
general space-time dimension. This solution is a natural generalization of the
stringlike defect solution with codimension 2 in 6 space-time dimensions, which
has been recently discovered by Gogberashvili and Singleton, to a general -brane solution with codimension in general space-time
dimensions. It is shown that all the local fields are localized on the brane
only through the gravitational interaction although this solution does not have
a warp factor and takes a finite value in the radial infinity. Thus, this
solution is a solution in an arbitrary space-time dimension realizing the idea
of "gravitational trapping" of the whole bulk fields on the brane within the
framework of a local field theory. Some problems associated with this solution
and localization are pointed out.Comment: 12 pages, no figures, Late
Topological Symmetry, Background Independence, and Matrix Models
We illustrate a physical situation in which topological symmetry, its
breakdown, space-time uncertainty principle, and background independence may
play an important role in constructing and understanding matrix models. First,
we show that the space-time uncertainty principle of string may be understood
as a manifestation of the breakdown of the topological symmetry in the large
matrix model. Next, we construct a new type of matrix models which is a
matrix model analog of the topological Chern-Simons and BF theories. It is of
interest that these topological matrix models are not only completely
independent of the background metric but also have nontrivial "p-brane"
solutions as well as commuting classical space-time as the classical solutions.
In this paper, we would like to point out some elementary and unsolved problems
associated to the matrix models, whose resolution would lead to the more
satisfying matrix model in future.Comment: 19 pages, LaTex, Invited paper to appear in the special issue of the
Journal of Chaos, Solitons and Fractals on "Superstrings, M, F, S, .......
Theory", edited by M.S. El Naschie and C. Castr
Evaporation of Three Dimensional Black Hole in Quantum Gravity
We discuss an evaporation of (2+1)-dimensional black hole by using quantum
gravity holding in the vicinity of the black hole horizon. It is shown that the
black hole evaporates at a definite rate by emitting matters through the
quantum tunneling effect. A relation of the present formalism to the black hole
entropy is briefly commented.Comment: 13 pages, phyzz
Antisymmetric Tensor Fields in the Locally Localized Gravity Models
We study the localization property of antisymmetric tensor fields in the
locally localized gravity models. It is shown that all the antisymmetric tensor
fields, including the vector field, in a bulk space-time are trapped on an
brane by a gravitational interaction where the presence of the brane
cosmological constant plays an important role as in the cases of the other bulk
fields. The normalized zero-modes spread rather widely in extra space so small
extra dimensions might be needed in order not to conflict with experiment.Comment: 9 pages, LaTex 2e, no figure
Thermodynamics of Black Hole in (N+3)-dimensions from Euclidean N-brane Theory
In this article we consider an N-brane description of an (N+3)-dimensional
black hole horizon. First of all, we start by reviewing a previous work where a
string theory is used as describing the dynamics of the event horizon of a four
dimensional black hole. Then we consider a particle model defined on one
dimensional Euclidean line in a three dimensional black hole as a target
spacetime metric. By solving the field equations we find a ``world line
instanton'' which connects the past event horizon with the future one. This
solution gives us the exact value of the Hawking temperature and to leading
order the Bekenstein-Hawking formula of black hole entropy. We also show that
this formalism is extensible to an arbitrary spacetime dimension. Finally we
make a comment of one-loop quantum correction to the black hole entropy
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