High Energy Physics

We consider pure three dimensional quantum gravity with a negative cosmological constant. The torus partition function can be computed exactly as a sum over geometries, including all known quantum corrections. The answer provides important clues about the structure of quantum gravity; in particular, in order for the theory to be a proper quantum mechanical system some extra ingredients are needed beyond the usual real geometries considered in general relativity. One possiblity is that complex geometries need to be included; this leads to holomorphically factorized partition functions. These partition functions provide a wealth of information about black hole microphysics. For example, the Hawking-page phase transition can be studied exactly; it is a phase transition of the type described by Lee and Yang, which is associated with a condensation of zeros in the complex temperature plane.

If some form of string theory indeed describes the ultra high energy physics of our universe, then there are two ingredients which are very likely to remain at low energies. The first, is a fifth force in the form of an additional abelian gauge group. The second, and more dramatic, is supersymmetry. Both may be observed at the upcoming Large Hadron Collider. In this talk I will explore a possible intimate connection between these two ingredients which leads to surprising predictions.

I will present a construction of supersymmetric Wilson loop operators in N=4 SYM for an arbitrary path on an S3 subspace of space-time. I will show how they are evaluated in AdS and in particular that the string world-sheet is a generalized calibration with respect to an almost-complex structure associate to the supersymmetries preserved by the loop. I will present some special examples and in the case when the loop is restricted to an S2, some evidence that the calculation reduces to a perturbative calculation in YM in 2-dimensions on S2. This in turn is exactly soluble in terms of a 0-dimensional matrix model.