We investigate the thermal phase structure of the Berenstein--Maldacena--Nastase (BMN) matrix model using non-perturbative lattice Monte Carlo calculations. Our main analyses span three orders of magnitude in the coupling, involving systems with sizes up to $N_{ \tau} = 24$ lattice sites and SU($N$) gauge groups with $8 \leq N \leq 16$. In addition, we carry out extended checks of discretization artifacts for $N_{ \tau} \leq 128$ and gauge group SU(4). We find results for the deconfinement temperature that interpolate between the perturbative prediction at weak coupling and the large-$N$ dual supergravity calculation at strong coupling. While we confirm that the phase transition is first order for strong coupling, it appears to be continuous for weaker couplings.
Categories: hep-lat hep-th