|Speaker:||Brian Wecht (IAS)|
|Title:||Recursion Relations and String Theory Amplitudes|
|Date (JST):||Wed, Jun 30, 2010, 15:30 - 17:00|
|Place:||Seminar Room A|
Abstract (Intro): In the past five years, there has been considerable progress in computing scattering amplitudes via recursive techniques. These techniques often are much simpler than directly computing Feynman diagrams, and also can make certain properties of the amplitudes manifest. In the introduction to my talk, I will review how these methods work in quantum field theory, and set up the framework for similar techniques in string theory amplitudes.
Abstract (seminar): The BCFW recursion relations are powerful tools for computing gauge theory amplitudes. In this talk, I will prove that these recursion relations also apply to all tree-level open and closed string amplitudes. Additionally, I will give evidence for the equivalence between string theory and field theory amplitudes in a particular limit where some momenta become arbitrarily small. I will also describe new recursive techniques which can be used for computing tachyon amplitudes in terms of lower-point tachyon amplitudes.