On the pp-wave limit and the BMN structure of new Sasaki-Einstein spaces
  We construct the pp-wave string associated with the Penrose limit of $Y^{p,q}$ and $L^{p,q,r}$ families of Sasaki-Einstein geometries. We identify in the dual quiver gauge theories the chiral and the non-chiral operators that correspond to the ground state and the first excited states. We present an explicit identification in a prototype model of $L^{1,7,3}$. 
Stanislav Kuperstein, Oded Mintkevich, Jacob Sonnenschein