Penrose limit and DLCQ of string theory

TL;DR

This paper explores the Penrose limit of string backgrounds as a generalization of the Seiberg-Sen limit, connecting it to DLCQ and providing insights into the BMN duality within string theory.

Contribution

It establishes a new perspective on the Penrose limit as a generalization of the Seiberg-Sen limit, linking it to DLCQ and clarifying features of the BMN duality.

Findings

Penrose limit generalizes Seiberg-Sen limit for string backgrounds.

DLCQ of string theory relates to Penrose limit and BMN theory.

Provides a conceptual framework for understanding BMN duality.

Abstract

We argue that the Penrose limit of a general string background is a generalization of the Seiberg-Sen limit describing M(atrix) theory as the DLCQ of M theory in flat space. The BMN theory of type IIB strings on the maximally supersymmetric pp-wave background is understood as the exact analogue of the BFSS M(atrix) theory, namely, a DLCQ of IIB string theory on $AdS_5 \times S^5$ in the limit of infinite longitudinal momentum. This point of view is used to explain some features of the BMN duality.