Penrose Limit of N = 1 Gauge Theories

We find a Penrose limit of AdS_5 × T^(1,1) which gives the pp-wave geometry identical to the one that appears in the Penrose limit of AdS_5 × S^5. This leads us to conjecture that there is a subsector of the corresponding N = 1 gauge theory which has enhanced N = 4 supersymmetry. We identify operators in the N = 1 gauge theory with stringy excitations in the pp-wave geometry and discuss how the gauge theory operators fall into N = 4 supersymmetry multiplets. We find similar enhancement of symmetry in some other models, but there are also examples in which there is no supersymmetry enhancement in the Penrose limit.