Matrix Perturbation Theory For M-theory On a PP-Wave

TL;DR

This paper analyzes the matrix model for M-theory on a pp-wave background, deriving it from supermembranes and D0-branes, and computes its spectrum and BPS states in the large  limit, establishing perturbative regimes.

Contribution

It provides a derivation of the matrix model from supermembrane and D0-brane perspectives and computes the spectrum and BPS states in the large  limit, clarifying the perturbative regime.

Findings

Exact spectrum computed in large  limit

Complete set of BPS states identified

Perturbation theory validity range estimated

Abstract

In this paper, we study the matrix model proposed by Berenstein, Maldacena, and Nastase to describe M-theory on the maximally supersymmetric pp-wave. We show that the model may be derived directly as a discretized theory of supermembranes in the pp-wave background, or alternatively, from the dynamics of D0-branes in type IIA string theory. We consider expanding the model about each of its classical supersymmetric vacua and note that for large values of the mass parameter \mu, interaction terms are suppressed by powers of 1/mu, so that the model may be studied in perturbation theory. We compute the exact spectrum about each of the vacua in the large \mu limit and find the complete (infinite) set of BPS states, which includes states preserving 2, 4, 6, 8, or 16 supercharges. Through explicit perturbative calculations, we then determine the effective coupling that controls the perturbation expansion for large \mu and estimate the range of parameters and energies for which perturbation theory is valid.