2008

What is the Simplest Quantum Field Theory?

Arkani-Hamed, Nima, Cachazo, Freddy, Kaplan, Jared

Understand

Conventional wisdom says that the simpler the Lagrangian of a theory the simpler its perturbation theory, but an increased understanding of the structure of the S-matrix in gauge theories and gravity has been pointing to the opposite conclusion.

  • In this paper we suggest that N=8 SUGRA has the simplest interacting S-matrix in 4D.
  • Using Grassmann coherent states for external particles shows that amplitudes with maximal SUSY are smooth objects, with the action of SUSY manifest.
  • We show that all tree amplitudes in N=4 SYM and N=8 SUGRA vanish at (supersymmetric) infinite complex momentum, and can thus be determined by recursion relations.

Reading the bibliography…