Fundamental Aspects of Superstring Theory

Coordinators: Melanie Becker, Nathan Berkovits, Joe G. Polchinski

Over the last decade, string theory has seen important conceptual and technical advances on a host of long-standing problems involving non-pertur-bative and strongly-coupled physics. However, the fundamental ingredients of superstring theory and M-theory are still not well understood, and this five month program will be directed at these open questions.

There has been recent progress on a variety of central technical problems and our goal is to further these advances and to develop the connections between them. To accomplish this, we have planned a series of overlapping focus periods during the first twelve weeks of the program, while the final nine weeks are left open for broader questions and new developments. The focus areas are:

Pure spinor formalism (weeks 1-6, Jan. 5-Feb. 13): This formalism has been useful for quantizing the superstring in Ramond-Ramond backgrounds, and has considerably simplified the computation of multiloop superstring scattering amplitudes. There are also indications that the formalism can be used to describe d=11 supergravity and M-theory.

String field theory (weeks 1-4, Jan. 5-Jan. 30): Schnabl's construction of an analytic solution of open string field theory has opened a window of opportunity for progress. Although the problem of closed string tachyon potentials remains quite mysterious, renewed efforts to understand their properties may lead to significant progress.

Integrability (weeks 5-8, Feb. 2-Feb. 27): There are strong indications that ${\cal N} = 4$ super-Yang-Mills theory is solvable, at least in the large-N limit. This would be a remarkable system, in that one would have not only the dual AdS and CFT descriptions at the extremes of the coupling, but a complete solution in between as well.

Topological string theory (weeks 7-12, Feb. 16-Mar. 27): Topological strings arise both in Calabi-Yau backgrounds of conventional superstrings, and as string theories on their own. Furthermore, topological strings exhibit the dualities of "physical" superstrings and can be viewed as a theoretical laboratory for testing various ideas about quantum gravity.

Flux compactifications (weeks 9-12, Mar. 2-Mar. 27): Flux compactifications in type II as well as heterotic theories are of interest in connection to moduli stabilization in string phenomenology as well as string cosmology. As opposed to compactifications on ordinary Calabi-Yau manifolds, the moduli fields can be stabilized in this type of compactifications.

Dualities in Physics and Mathematics (week 11, Mar 16-20): This week will be devoted to exploring the newly found connections between various dualities in physics (such as the S-duality in 4D supersymmetric gauge theory and Mirror Symmetry of 2D-sigma models) and in mathematics (geometric Langlands Program.) The additional coordinators for this week are Edward Frenkel and David Morrison; further information may be found here.

New developments & other topics (weeks 13-21, Mar. 30-May 29): Other subjects which may be addressed during these two months include the counting of black hole microstates, cosmological vacuum selection and the lessons of the landscape, the description of spacelike singularities, the origins of holography, the development of new mechanisms for supersymmetry breaking, and a host of mathematical correlates.

80th Birthday Celebration: There will be a celebration of Stanley Mandelstam's work on Friday, February 13, 2009.