5 research outputs found
Quantum field theory on manifolds with a boundary
We discuss quantum theory of fields \phi defined on (d+1)-dimensional
manifold {\cal M} with a boundary {\cal B}. The free action W_{0}(\phi) which
is a bilinear form in \phi defines the Gaussian measure with a covariance
(Green function) {\cal G}. We discuss a relation between the quantum field
theory with a fixed boundary condition \Phi and the theory defined by the Green
function {\cal G}. It is shown that the latter results by an average over \Phi
of the first. The QFT in (anti)de Sitter space is treated as an example. It is
shown that quantum fields on the boundary are more regular than the ones on
(anti) de Sitter space.Comment: The version to appear in Journal of Physics A, a discussion on the
relation to other works in the field is adde
Alpha-Vacua, Black Holes, and AdS/CFT
The Schwarzschild, Schwarzschild-AdS, and Schwarzschild-de Sitter solutions
all admit freely acting discrete involutions which commute with the continuous
symmetries of the spacetimes. Intuitively, these involutions correspond to the
antipodal map of the corresponding spacetimes. In analogy with the ordinary de
Sitter example, this allows us to construct new vacua by performing a
Mottola-Allen transform on the modes associated with the Hartle-Hawking, or
Euclidean, vacuum. These vacua are the `alpha'-vacua for these black holes. The
causal structure of a typical black hole may ameliorate certain difficulties
which are encountered in the case of de Sitter alpha-vacua. For
Schwarzschild-AdS black holes, a Bogoliubov transformation which mixes
operators of the two boundary CFT's provides a construction of the dual CFT
alpha-states. Finally, we analyze the thermal properties of these vacua.Comment: 40 pages REVTeX and AMSLaTeX, 17 black&white eps figures. v3:
references added. v4: details of the pinch singularity avoidance for the
string quantization of the Rindler space toy model have been added in both
the body of the paper and in a new 7 page appendix. Other clarifications and
references added. This is the version accepted for publication in Class.
Quant. Gra
The Bekenstein Formula and String Theory (N-brane Theory)
A review of recent progress in string theory concerning the Bekenstein
formula for black hole entropy is given. Topics discussed include p-branes,
D-branes and supersymmetry; the correspondence principle; the D- and M-brane
approach to black hole entropy; the D-brane analogue of Hawking radiation, and
information loss; D-branes as probes of black holes; and the Matrix theory
approach to charged and neutral black holes. Some introductory material is
included.Comment: 53 pages, LaTeX. v3: Typos fixed, minor updates, references added,
brief Note Added on AdS/CF
Holography and Brane-bulk Energy Exchange
The five-dimensional description of generalized Randall-Sundrum cosmology is
mapped via holography to a generalization of the Starobinsky model. This
provides a holographic dual description of the cosmological brane-bulk energy
exchange processes studied previously. Some simple solutions are presented in
four dimensions.Comment: 41 pages, LaTe