High Energy Theory Seminar
I'll talk about a recent reinterpretation of tree-level string theory amplitudes in terms of twisted homology and cohomology in the moduli space of Riemann surfaces. In this formulation the Kawai-Lewellen-Tye (KLT) relations between closed and open string amplitudes gain a geometric interpretation in terms of intersection theory in this twisted homology. Moreover, it unifies the description of other string-like models such as Witten's Twistor string and the more recent Ambitwistor string, clarifying their relation to usual string theory. From there I'll talk about recent work in generalizing this framework to higher genus surfaces. I'll use this to derive all genus monodromy relations between string integrands and to give a conjecture for the size of a basis of string integrands, which generalizes the (n-3)! for tree-level string amplitudes. I'll discuss some interesting facts about their field theory limit which gives rise to relations for field theory amplitudes and integrands, and end with a short discussion on prospects of KLT at higher genus.