EDUCATION:

Ph.D. 1993, M.I.T.

RESEARCH:

My main research interests are in the area of non-perturbative string theory and its applications to quantum gravity and cosmology. In recent years people have finally understood how to give complete non-perturbative definitions of string theory in certain background spacetimes, via the so-called Matrix and AdS/CFT conjectures. These conjectures state that gravitational physics in a bulk spacetime with certain asymptotic boundary conditions is completely equivalent to a non-gravitational theory localized on the boundary of the spacetime. I've been studying the way in which gravitational physics - for example a black hole in the bulk spacetime - gets encoded in the boundary theory [1,2,3]. I'm also interested in applications of string theory to cosmology. In particular I've been investigating a cosmological scenario put forward by Brandenberger and Vafa in which the dynamics of extended objects in the early universe play a key role. The idea is that if you start with all dimensions curled up, string theory might be dynamically unstable to decompactifying three spatial dimensions. Our preliminary results indicate that it's difficult to keep the string interaction rate high enough [4,5,6]. I'm currently looking at whether taking the chaotic dynamics of the early universe into account could help fix this problem [7].

SELECTED PUBLICATIONS:

A complete list of publications is available from the e-print archive

1. "Quasiparticle picture of black holes and the entropy-area relation" (with N. Iizuka, G Lifschytz and D. Lowe), e-print archive: hep-th/0212246.

2. "Stretched horizons, quasiparticles and quasinormal modes" (with N. Iizuka, G. Lifschytz and D. Lowe), e-print archive: hep-th/0306209.

3. "Non-local operators in the AdS/CFT correspondence" (with A. Hamilton, G. Lifschytz and D. Lowe), in progress.

4. "Brane gas cosmology in M-theory: late time behavior" (with R. Easther, B. R. Greene and M. Jackson), e-print archive: hep-th/0211124.

5. "Brane gases in the early universe" (with R. Easther, B. R. Greene and M. Jackson), e-print archive: hep-th/0307233.

6. "String windings in the early universe" (with R. Easther, B. R. Greene and M. Jackson), e-print archive: hep-th/0409121.

7. "Chaos and U-duality in string gas cosmology" (with N. Petrovic), in progress.