591 research outputs found
Notes on SU(3) Structures in Type IIB Supergravity
We study solutions of type IIB supergravity with an SU(3) structure group and
four dimensional Poincare invariance and present relations among the bosonic
fields which follow from the supersymmetry variations. We make explicit some
results which also follow from the more general case of an SU(2) structure and
give some short comments applicable to general supersymmetric solutions. We
also provide simplified relations appropriate for duals of gauge theory
renormalization group flows, and use these to derive the supergravity solution
for a bound state of (p,q)5-branes and D3-branes.Comment: 14p, JHEP3.cls, v2 typos corrected, refs adde
Towards A Nonsingular Tachyonic Big Crunch
We discuss an effective field theory background containing the gravitational
field, the dilaton and a closed string tachyon, and couple this background to a
gas of fundamental strings and D strings. Allowing for the possibility of a
non-vanishing dilaton potential of Casimir type, we demonstrate the possibility
of obtaining a nonsingular, static tachyon condensate phase with fixed dilaton.
The time reversal of our solution provides a candidate effective field theory
description of a Hagedorn phase of string gas cosmology with fixed dilaton.Comment: 7 pages, two references adde
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