Triangle Seminars

Abstract:
When an integrable quantum field theory in one space dimension
has a Lie group symmetry, the Lie algebra is typically embedded in a
larger algebra called a Yangian. When one adds a boundary which
preserves integrability, this is extended to a (generalized) twisted
Yangian. We explain the role of these algebras in physics, and in
particular recent work by MacKay and Regelskis which uncovers their
governing role in the scattering of worldsheet excitations off D-branes
in the AdS/CFT correspondence.

Abstract:
Four-dimensional supersymmetric type II string theory vacua can be described elegantly in terms of pure spinors on the generalized tangent bundle T+T. This leads to constraints on M6 involving Hitchin's "generalized complex geometry". In this talk, we apply the same techniques to any ten-dimensional supersymmetric solution, not necessarily factorized as AdS4xM6 or Mink4xM6. I will describe a system of differential equations in terms of forms describing a "generalized ISpin(7) structure" is equivalent to unbroken supersymmetry, in both IIA and IIB. One of the equations in the system reproduces in one fell swoop all the pure spinors equations for four-dimensional vacua.