291 research outputs found
On the Stability of a Stringy Black Hole
We study the stability under perturbations of a charged four dimensional
stringy black hole arising from gauging a previously studied WZW model. We find
that the black hole is stable only in the extremal case .Comment: 14 pages + 1 figure (not included but available on request
Exotic prepotentials from D(-1)D7 dynamics
We compute the partition functions of D(-1)D7 systems describing the
multi-instanton dynamics of SO(N) gauge theories in eight dimensions. This is
the simplest instance of the so called exotic instantons. In analogy with the
Seiberg-Witten theory in four space-time dimensions, the prepotential and
correlators in the chiral ring are derived via localization formulas and found
to satisfy relations of the Matone type. Exotic prepotentials of SO(N) gauge
theories with N=2 supersymmetries in four-dimensions are also discussed.Comment: 19 page
Quantum Models of Black Hole Evaporation
The discovery of black-hole evaporation represented in many respects a
revolutionary event in scientific world; as such, in giving answers to open
questions, it gave rise to new problems part of which are still not resolved.
Here we want to make a brief review of such problems and examine some possible
solutions. Invited Talk at the "Workshop on String Theory, Quantum Gravity and
the Unification of the Fundamental Interactions" Rome, September 21-26Comment: 9 pages, ROM2F-92/6
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