Probing universality in the gravity duals of Script N = 1 SYM by γ deformations

Recently, a one-parameter deformation of the Maldacena-Nunez dual of the N=1SYM theory was constructed in hep-th/0505100. According to the Lunin-Maldacenaconjecture, the background is dual to pure N=1 SYM in the IR coupled to a KKsector whose dynamics is altered by a dipole deformation that is proportionalto the deformation parameter gamma. Thus, the deformation serves to identifythe aspects of the gravity backgrounds that bear the effects of the KK sector,hence non-universal in the dual gauge theory. We make this idea concrete bystudying a Penrose limit of the deformed MN theory. We obtain an exactlysolvable pp-wave that is conjectured to describe the IR dynamics of KK-hadronsin the field theory. The spectrum, the thermal partition function and theHagedorn temperature are calculated. The Hagedorn temperature turns out to beindependent of the deformation parameter.Comment: 29 pages, 1 figure, refs. added, typos corrected, v3: discussion extended and modified v4: discussion section modified, typos corrceted, v5: referencing correcte