String interactions and discrete symmetries of the pp-wave background

TL;DR

This paper investigates the discrete symmetries of free string theory in a pp-wave background, demonstrating the completion of the zero mode structure into a full kinematical vertex and discussing implications for string interactions and dual field theories.

Contribution

It shows that the zero mode structure can be extended to a complete kinematical vertex, clarifying previous claims and enhancing understanding of string interactions in pp-wave backgrounds.

Findings

Zero mode structure can be completed to a full kinematical vertex

The Z2 symmetry is preserved at the interacting level

Discussion on relation to string-bit formalism and field theory duals

Abstract

Free string theory on the plane-wave background displays a discrete Z2 symmetry exchanging the two transverse SO(4) rotation groups. This symmetry should be respected also at the interacting level. We show that the zero mode structure proposed in hep-th/0208148 can be completed to a full kinematical vertex, contrary to claims appeared in the previous literature. We also comment on the relation with recent works on the string-bit formalism and on the comparison with the field theory side of the correspondence.