High energy scattering amplitudes in matrix string theory

TL;DR

This paper investigates high energy scattering in matrix string theory, demonstrating that classical backgrounds and zero mode analysis reproduce key features of string scattering amplitudes, including Lorentz invariance and coupling dependence.

Contribution

It provides a detailed one-loop fluctuation analysis around classical backgrounds in matrix string theory, reproducing the high energy limit of four graviton scattering amplitudes.

Findings

Reproduces the high energy limit of four graviton scattering amplitude.

Shows Lorentz invariant kinematic structure from fermion zero modes.

Obtains correct string coupling dependence from gauge field zero modes.

Abstract

High energy fixed angle scattering is studied in matrix string theory. The saddle point world sheet configurations, which give the dominant contributions to the string theory amplitude, are taken as classical backgrounds in matrix string theory. A one loop fluctuation analysis about the classical background is performed. An exact treatment of the fermionic and bosonic zero modes is shown to lead to all of the expected structure of the scattering amplitude. The ten dimensional Lorentz invariant kinematical structure is obtained from the fermion zero modes, and the correct factor of the string coupling constant is obtained from the abelian gauge field zero modes. Up to a numerical factor we reproduce, from matrix string theory, the high energy limit of the tree level, four graviton scattering amplitude.