(28.04.) Berends-Giele currents, string amplitudes and gauge invariance
28.04.2016 at 16:15
In this talk, the recursive method of Berends and Giele to resum Feynman diagrams of gauge theories is applied to string amplitudes. The kinematic dependence of open- and closed-string amplitudes at tree level and one loop is efficiently organized in terms of Berends-Giele currents. Gauge invariant combinations of currents are systematically constructed and identified in string amplitudes after reducing their worldsheet integrals to a
basis. One-loop amplitudes with different amount of supersymmetry are shown to exhibit the same patterns of worldsheet functions and kinematic factors. Partial supersymmetry breaking is argued to introduce the same complexity as two additional particles in a maximally supersymmetric context, paving the way for multiparticle amplitudes in orbifold compactifications.
Arnold Sommerfeld Center