Gravity from quantum mechanics of finite matrices

We revisit the Berenstein-Maldacena-Nastase (BMN) conjecture relating M-theory on a PP-wave background and Matrix Quantum Mechanics (MQM). In particular, we discuss the PP-wave version of "another conjecture" for Matrix Theory by Susskind, relating BMN MQM at finite N to DLCQ of M-theory on a PP-wave. We study the model at strong coupling and find that the spectrum matches that of supergravity. Our derivation is based on the strong coupling expansion of the wavefunction and supersedes the naive path integral approach that can lead to incorrect results, as we demonstrate in a simple toy model. We end with mentioning open questions and future directions.