690 research outputs found
BF Actions for the Husain-Kuchar Model
We show that the Husain-Kuchar model can be described in the framework of BF
theories. This is a first step towards its quantization by standard
perturbative QFT techniques or the spin-foam formalism introduced in the
space-time description of General Relativity and other diff-invariant theories.
The actions that we will consider are similar to the ones describing the
BF-Yang-Mills model and some mass generating mechanisms for gauge fields. We
will also discuss the role of diffeomorphisms in the new formulations that we
propose.Comment: 21 pages (in DIN A4 format), minor typos corrected; to appear in
Phys. Rev.
Quasinormal Modes and Black Hole Quantum Mechanics in 2+1 Dimensions
We explore the relationship between classical quasinormal mode frequencies
and black hole quantum mechanics in 2+1 dimensions. Following a suggestion of
Hod, we identify the real part of the quasinormal frequencies with the
fundamental quanta of black hole mass and angular momentum. We find that this
identification leads to the correct quantum behavior of the asymptotic symmetry
algebra, and thus of the dual conformal field theory. Finally, we suggest a
further connection between quasinormal mode frequencies and the spectrum of a
set of nearly degenerate ground states whose multiplicity may be responsible
for the Bekenstein-Hawking entropy.Comment: 8 pages, LaTeX; references added and corrected, introduction and
conclusion slightly expande
Algebraic characterization of the Wess-Zumino consistency conditions in gauge theories
A new way of solving the descent equations corresponding to the Wess-Zumino
consistency conditions is presented. The method relies on the introduction of
an operator which allows to decompose the exterior space-time
derivative as a commutator. The case of the Yang-Mills theories is
treated in detail.Comment: 16 pages, UGVA-DPT 1992/08-781 to appear in Comm. Math. Phy
Symmetries of topological field theories in the BV-framework
Topological field theories of Schwarz-type generally admit symmetries whose
algebra does not close off-shell, e.g. the basic symmetries of BF models or
vector supersymmetry of the gauge-fixed action for Chern-Simons theory (this
symmetry being at the origin of the perturbative finiteness of the theory). We
present a detailed discussion of all these symmetries within the algebraic
approach to the Batalin-Vilkovisky formalism. Moreover, we discuss the general
algebraic construction of topological models of both Schwarz- and Witten-type.Comment: 30 page
Quasinormal modes of d-dimensional spherical black holes with a near extreme cosmological constant
We derive an expression for the quasinormal modes of scalar perturbations in
near extreme d-dimensional Schwarzschild-de Sitter and Reissner-Nordstrom-de
Sitter black holes. We show that, in the near extreme limit, the dynamics of
the scalar field is characterized by a Poschl-Teller effective potential. The
results are qualitatively independent of the spacetime dimension and field
mass.Comment: 5 pages, REVTeX4, version to be published in Physical Review
Sny Magill Nonpoint Source Pollution Monitoring Project : final report
https://ir.uiowa.edu/igs_tis/1047/thumbnail.jp
Cardy-Verlinde Formula and AdS Black Holes
In a recent paper hep-th/0008140 by E. Verlinde, an interesting formula has
been put forward, which relates the entropy of a conformal formal field in
arbitrary dimensions to its total energy and Casimir energy. This formula has
been shown to hold for the conformal field theories that have AdS duals in the
cases of AdS Schwarzschild black holes and AdS Kerr black holes. In this paper
we further check this formula with various black holes with AdS asymptotics.
For the hyperbolic AdS black holes, the Cardy-Verlinde formula is found to hold
if we choose the ``massless'' black hole as the ground state, but in this case,
the Casimir energy is negative. For the AdS Reissner-Nordstr\"om black holes in
arbitrary dimensions and charged black holes in D=5, D=4, and D=7 maximally
supersymmetric gauged supergravities, the Cardy-Verlinde formula holds as well,
but a proper internal energy which corresponds to the mass of supersymmetric
backgrounds must be subtracted from the total energy. It is failed to rewrite
the entropy of corresponding conformal field theories in terms of the
Cardy-Verlinde formula for the AdS black holes in the Lovelock gravity.Comment: 18 pages, latex, no figures, discussions on the charged AdS black
holes change
Differential Regularization of Topologically Massive Yang-Mills Theory and Chern-Simons Theory
We apply differential renormalization method to the study of
three-dimensional topologically massive Yang-Mills and Chern-Simons theories.
The method is especially suitable for such theories as it avoids the need for
dimensional continuation of three-dimensional antisymmetric tensor and the
Feynman rules for three-dimensional theories in coordinate space are relatively
simple. The calculus involved is still lengthy but not as difficult as other
existing methods of calculation. We compute one-loop propagators and vertices
and derive the one-loop local effective action for topologically massive
Yang-Mills theory. We then consider Chern-Simons field theory as the large mass
limit of topologically massive Yang-Mills theory and show that this leads to
the famous shift in the parameter . Some useful formulas for the calculus of
differential renormalization of three-dimensional field theories are given in
an Appendix.Comment: 25 pages, 4 figures. Several typewritten errors and inappropriate
arguments are corrected, especially the correct adresses of authors are give
Physically meaningful and not so meaningful symmetries in Chern-Simons theory
We explicitly show that the Landau gauge supersymmetry of Chern-Simons theory
does not have any physical significance. In fact, the difference between an
effective action both BRS invariant and Landau supersymmetric and an effective
action only BRS invariant is a finite field redefinition. Having established
this, we use a BRS invariant regulator that defines CS theory as the large mass
limit of topologically massive Yang-Mills theory to discuss the shift k \to
k+\cv of the bare Chern-Simons parameter in conncection with the Landau
supersymmetry. Finally, to convince ourselves that the shift above is not an
accident of our regularization method, we comment on the fact that all BRS
invariant regulators used as yet yield the same value for the shift.Comment: phyzzx, 21 pages, 2 figures in one PS fil
Cosmological Plebanski theory
We consider the cosmological symmetry reduction of the Plebanski action as a
toy-model to explore, in this simple framework, some issues related to loop
quantum gravity and spin-foam models. We make the classical analysis of the
model and perform both path integral and canonical quantizations. As for the
full theory, the reduced model admits two types of classical solutions:
topological and gravitational ones. The quantization mixes these two solutions,
which prevents the model to be equivalent to standard quantum cosmology.
Furthermore, the topological solution dominates at the classical limit. We also
study the effect of an Immirzi parameter in the model.Comment: 20 page
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