Holographic entanglement entropy of the near horizon 1/4 BPS F-D$p$ bound states

Abstract: It was shown in Dey and Roy (2012) that the near horizon limit of the 1/4 BPS threshold F-D$p$ (for $0\leq p \leq 5$, $p \neq 4$) bound state solutions of type II string theories give rise to space-time metrics endowed with Lifshitz scaling along with hyperscaling violation. Here we compute the holographic entanglement entropy of this system for all $p \neq 4$ (for $p=4$ the space-time has AdS$_2$ structure). For $p=3,5$, we get the expected area law behavior of the entanglement entropy. For $p=0,1$, the entanglement entropy has new area law violations and has the behavior which is in between the linear and logarithmic behaviors. For $p=2$, we get a logarithmic violation of the area law. We also compute the entanglement entropy at finite temperature and show that as the temperature rises, the entanglement entropy makes a crossover to the thermal entropy of the system. We thus obtain the string theoretic realization of holographic EE and various of its aspects noted earlier for generic metric with hyperscaling violation.