Orbifolds, Penrose Limits and Supersymmetry Enhancement

TL;DR

This paper explores supersymmetric Penrose limits of various orbifold geometries related to AdS/CFT correspondence, revealing conditions for supersymmetry enhancement and identifying dual gauge operators.

Contribution

It systematically analyzes different orbifold geometries and their Penrose limits, detailing supersymmetry preservation and dual operator identification.

Findings

Maximal and half-maximal supersymmetric PP-wave geometries identified.

Explicit gauge-invariant operators corresponding to string excitations determined.

Conditions for supersymmetry enhancement in orbifold limits clarified.

Abstract

We consider supersymmetric PP-wave limits for different N=1 orbifold geometries of the five sphere S^5 and the five dimensional Einstein manifold T^{1,1}. As there are several interesting ways to take the Penrose limits, the PP-wave geometry can be either maximal supersymmetric N=4 or half-maximal supersymmetric N=2. We discuss in detail the cases AdS_5 x S^5/Z_3, AdS_5 x S^5/(Z_m x Z_n) and AdS_5 x T^{1,1}/(\Z_m \times \Z_n) and we identify the gauge invariant operators which correspond to stringy excitations for the different limits.