67 research outputs found
Discrete Quantum Field Theories and the Intersection Form
It is shown that the standard mod- valued intersection form can be used to
define Boltzmann weights of subdivision invariant lattice models with gauge
group . In particular, we discuss a four dimensional model which is
based upon the assignment of field variables to the -simplices of the
simplicial complex. The action is taken to be the intersection form defined on
the second cohomology group of the complex, with coefficients in .
Subdivision invariance of the theory follows when the coupling constant is
quantized and the field configurations are restricted to those satisfying a
mod- flatness condition. We present an explicit computation of the partition
function for the manifold , demonstrating non-triviality.Comment: 10 pages, Latex, ITFA-94-1
Entropy of Three-Dimensional Black Holes in String Theory
It is observed that the three-dimensional BTZ black hole is a supersymmetric
solution of the low-energy field equations of heterotic string theory
compactified on an Einstein space. The solution involves a non-zero dilaton and
NS-NS H-field. The entropy of the extreme black hole can then be computed using
string theory and the asymptotic properties of anti-de Sitter space, without
recourse to a D-brane analysis. This provides an explicit example of a black
hole whose entropy can be computed using fundamental string theory, as
advocated by Susskind.Comment: 7 pages, Latex, Two additional reference
Classical Stability of the BTZ Black Hole in Topologically Massive Gravity
We demonstrate the classical stability of the BTZ black hole within the
context of topologically massive gravity. The linearized perturbation equations
can be solved exactly in this case. By choosing standard boundary conditions
appropriate to the stability problem, we demonstrate the absence of modes which
grow in time, for all values of the Chern-Simons coupling.Comment: 11 page
Generalized Skein Relations from Chern-Simons Field Theory
Using a variational approach based only on three dimensional properties of Chern-Simons theory, a skein relation for the expectation value of Wilson line operators in the adjoint representation of SU(2) is derived, in the large k limit. The result agrees with that obtained from RCFT. The generalization to arbitrary representations is then straighforward, once an important phase factor present in our example is understood
The Eta Function in Chern-Simons Field Theory
We discuss a Schwinger expansion technique for computing the η-function of a first order operator in the pure Chern-Simons quantum field theory. When evaluated at zero, the η-function of this operator gives essentially the one-loop correction to the partition function. We illustrate this technique by explicitly computing the one-loop 2-point function in this theory on a fiat spacetime background
Brane World in a Topological Black Hole Bulk
We consider a static brane in the background of a topological black hole, in
arbitrary dimensions. For hyperbolic horizons, we find a solution only when the
black hole mass assumes its minimum negative value. In this case, the tension
of the brane vanishes, and the brane position coincides with the location of
the horizon. For an elliptic horizon, we show that the massless mode of
Randall-Sundrum is recovered in the limit of large black hole mass.Comment: Latex, 8 pages, v2: Additional references, to appear in MPL
On Dijkgraaf-Witten Type Invariants
We explicitly construct a series of lattice models based upon the gauge group
which have the property of subdivision invariance, when the coupling
parameter is quantized and the field configurations are restricted to satisfy a
type of mod- flatness condition. The simplest model of this type yields the
Dijkgraaf-Witten invariant of a -manifold and is based upon a single link,
or -simplex, field. Depending upon the manifold's dimension, other models
may have more than one species of field variable, and these may be based on
higher dimensional simplices.Comment: 18 page
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