#### High Energy Theory Informal Seminar - David Marsh, Cornell University - Wasteland of Random Supergravities

Abstract: I will discuss how in a general N = 1 supergravity with N ? 1 scalar fields, an exponentially small fraction of the de Sitter critical points are metastable vacua. For random superpotentials and Kähler potentials, the Hessian matrix is well-approximated by a simple matrix model, from which the eigenvalue spectrum can be obtained analytically by the techniques of random matrix theory. For typical critical points, a significant fraction of the eigenvalues are negative, and eigenvalue repulsion makes metastable critical points extremely rare, constituting a fraction of exp(?cN^p) of all critical points, where numerical evidence suggests p ? 1.5 for generic critical points.These results have significant implications for the counting of de Sitter vacua in string theory, but the number of vacua remains vast.

**Location:**
Other See Notes

**Date/Time: **02/28/12
at
12:30 pm
- 02/28/12
at
2:00 pm

To be held in the PCTS Lounge

**Category: **High Energy Experiment Seminar

**Department: **Physics