2,288 research outputs found
Geometric Finiteness and Non-quasinormal Modes of the BTZ Black Hole
The BTZ black hole is geometrically finite. This means that its three
dimensional hyperbolic structure as encoded in its metric is in 1-1
correspondence with the Teichmuller space of its boundary, which is a two
torus. The equivalence of different Teichmuller parameters related by the
action of the modular group therefore requires the invariance of the
monodromies of the solutions of the wave equation around the inner and outer
horizons in the BTZ background. We show that this invariance condition leads to
the non-quasinormal mode frequencies discussed by Birmingham and Carlip.Comment: 8 Pages, Latex file, minor changes in the text, journal versio
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
Construction of topological field theories using BV
We discuss in detail the construction of topological field theories using the
Batalin--Vilkovisky (BV) quantisation scheme. By carefully examining the
dependence of the antibracket on an external metric, we show that
differentiating with respect to the metric and the BRST charge do not commute
in general. We introduce the energy momentum tensor in this scheme and show
that it is BRST invariant, both for the classical and quantum BRST operators.
It is antifield dependent, guaranteeing gauge independence. For topological
field theories, this energy momentum has to be quantum BRST exact. This leads
to conditions at each order in . As an example of this procedure, we
consider topological Yang--Mills theory. We show how the reducible set of
symmetries used in topological Yang--Mills can be recovered by means of trivial
systems and canonical transformations. Self duality of the antighosts is
properly treated by introducing an infinite tower of auxiliary fields. Finally,
it is shown that the full energy momentum tensor is classically BRST exact in
the antibracket sense.Comment: 15
Non-Quasinormal Modes and Black Hole Physics
The near-horizon geometry of a large class of extremal and near-extremal
black holes in string and M theory contains three-dimensional asymptotically
anti-de Sitter space. Motivated by this structure, we are led naturally to a
discrete set of complex frequencies defined in terms of the monodromy at the
inner and outer horizons of the black hole. We show that the correspondence
principle, whereby the real part of these ``non-quasinormal frequencies'' is
identified with certain fundamental quanta, leads directly to the correct
quantum behavior of the near-horizon Virasoro algebra, and thus the black hole
entropy. Remarkably, for the rotating black hole in five dimensions we also
reproduce the fractionization of conformal weights predicted in string theory.Comment: 4 pages, revtex4; v2: reference added; v3: more references, minor
typo corrected; v4: minor rewording to adjust size (ugh!); v5: some small
clarifications at referees' suggestio
Birmingham’s Eastside story: making steps towards sustainability?
Sustainability has come to play a dominant discursive role in the UK planning system, particularly relating to urban regeneration. The purpose of this paper is to evaluate the role that sustainability plays in a major regeneration
programme, known as Eastside, currently underway in Birmingham, the UK. That this ÂŁ6 billion redevelopment is now widely talked about by such key players as Birmingham City Council and the Regional Development Agency, Advantage West Midlands, as having a central sustainability agenda points to the growing importance of the ideal of sustainability in planning and regeneration agendas. In this paper, we investigate in detail how and why sustainability has become part of the planning discourse for Eastside and critically evaluate what impact, if any, this is having on public policy decision-making
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