  In this article we prove the global existence of a unique strong solution to
the initial boundary-value problem for a fourth-order exponential PDE. The
equation we study was originally proposed to study the evolution of crystal
surfaces, and was derived by applying a nonstandard scaling regime to a
microscopic Markov jump process with Metropolis rates. Our investigation here
finds that compared to the PDE's which use Arhenious rates, (and also have a
fourth order exponential nonlinearity) the hyperbolic sine nonlinearity in our
equation can offer much better control over the exponent term even in high
dimensions.
