25 research outputs found
Dualities in fractional statistics
We first reobtain in a simpler way the Haldane fractional statistics at
thermal equilibrium using an interpolation argument. We then show that the mean
occupation number for fractional statistics is invariant to a group of duality
transformations, a nonabelian subgroup of the fractional linear groupComment: 7 pages, no figur
Our World as an Expanding Shell
In the model where the Universe is considered as a thin shell expanding in
5-dimensional hyper-space there is a possibility to have just one scale for a
particle theory corresponding to the Universe thickness. From a realistic model
the relation of this parameter to the Universe size was found.Comment: RevTeX, 4 pages, no figure
Non-commutative multi-dimensional cosmology
A non-commutative multi-dimensional cosmological model is introduced and used
to address the issues of compactification and stabilization of extra dimensions
and the cosmological constant problem. We show that in such a scenario these
problems find natural solutions in a universe described by an increasing time
parameter.Comment: 9 pages, 1 figure, to appear in JHE
Boundary conditions in the Unruh problem
We have analyzed the Unruh problem in the frame of quantum field theory and
have shown that the Unruh quantization scheme is valid in the double Rindler
wedge rather than in Minkowski spacetime. The double Rindler wedge is composed
of two disjoint regions (- and -wedges of Minkowski spacetime) which are
causally separated from each other. Moreover the Unruh construction implies
existence of boundary condition at the common edge of - and -wedges in
Minkowski spacetime. Such boundary condition may be interpreted as a
topological obstacle which gives rise to a superselection rule prohibiting any
correlations between - and - Unruh particles. Thus the part of the field
from the -wedge in no way can influence a Rindler observer living in the
-wedge and therefore elimination of the invisible "left" degrees of freedom
will take no effect for him. Hence averaging over states of the field in one
wedge can not lead to thermalization of the state in the other. This result is
proved both in the standard and algebraic formulations of quantum field theory
and we conclude that principles of quantum field theory does not give any
grounds for existence of the "Unruh effect".Comment: 31 pages,1 figur
Higher dimensional flat embeddings of (2+1) dimensional black holes
We obtain the higher dimensional global flat embeddings of static, rotating,
and charged BTZ black holes. On the other hand, we also study the similar
higher dimensional flat embeddings of the (2+1) de Sitter black holes which are
the counterparts of the anti-de Sitter BTZ black holes. As a result, the
charged dS black hole is shown to be embedded in (3+2) GEMS, contrast to the
charged BTZ one having (3+3) GEMS structure.Comment: 16pages, revtex, no figures, to appear in Phys. Rev.
Global embeddings of scalar-tensor theories in (2+1)-dimensions
We obtain (3+3)- or (3+2)-dimensional global flat embeddings of four
uncharged and charged scalar-tensor theories with the parameters B or L in the
(2+1)-dimensions, which are the non-trivially modified versions of the
Banados-Teitelboim-Zanelli (BTZ) black holes. The limiting cases B=0 or L=0
exactly are reduced to the Global Embedding Minkowski Space (GEMS) solution of
the BTZ black holes.Comment: 19 pages, 2 figure
Higher dimensional flat embeddings of black strings in (2+1) dimensions
We obtain (3+1) and (3+2) dimensional global flat embeddings of (2+1)
uncharged and charged black strings, respectively. In particular, the charged
black string, which is the dual solution of the Banados-Teitelboim-Zanelli
black holes, is shown to be embedded in the same global embedding Minkowski
space structure as that of the (2+1) charged de Sitter black hole solution.Comment: 11 pages, REVTEX, no figur