89 research outputs found
Black-holes, topological strings and large N phase transitions
The counting of microstates of BPS black-holes on local Calabi-Yau of the
form is explored
by computing the partition function of q-deformed Yang-Mills theory on .
We obtain, at finite , the instanton expansion of the gauge theory. It can
be written exactly as the partition function for U(N) Chern-Simons gauge theory
on a Lens space, summed over all non-trivial vacua, plus a tower of
non-perturbative instanton contributions. In the large limit we find a
peculiar phase structure in the model. At weak string coupling the theory
reduces to the trivial sector and the topological string partition function on
the resolved conifold is reproduced in this regime. At a certain critical
point, instantons are enhanced and the theory undergoes a phase transition into
a strong coupling regime. The transition from the strong coupling phase to the
weak coupling phase is of third order.Comment: 16 pages, 3 figures; Invited talk given at QG05, Cala Gonone (Italy),
September 200
Black Holes and Causal Structure in Anti-de Sitter Isometric Spacetimes
The observation that the 2+1 dimensional BTZ black hole can be obtained as a
quotient space of anti-de Sitter space leads one to ask what causal behaviour
other such quotient spaces can display. In this paper we answer this question
in 2+1 and 3+1 dimensions when the identification group has one generator.
Among other things we find that there does not exist any 3+1 generalization of
the rotating BTZ hole. However, the non-rotating generalization exists and
exhibits some unexpected properties. For example, it turns out to be non-static
and to possess a non-trivial apparent horizon.Comment: LaTeX, 22 pages, 10 postscript figures, uses epsf.te
The General Weak Interaction............................................................................................... 6
Abstract..............................................................................................................................
- …