Giant Gravitons on Deformed pp-waves

Abstract

The recently constructed Lunin-Maldacena deformation of $AdS_{5}\times S^{5}$ is known to support two inequivalent Penrose limits that lead to BPS pp-wave geometries. In this note, we construct new giant graviton solutions on these backgrounds. A detailed study of the spectra of small fluctuations about these solutions reveals a remarkably rich structure. In particular, the giants that we contruct fall into two classes, one of which appears to remain stable in the Penrose limit independently of the strength of the deformation. The other class of giants, while more difficult to treat analytically, seems to exhibit a shape deformation not unlike the so-called "squashed giants" seen in the pp-wave with a constant NS $B$-field turned on. Some consideration is also given to the associated giant operators in the BMN limit of the dual ${\cal N}=1$ SYM gauge theory.