Complexity of bipartite spherical spin glasses

Benjamin McKenna

Published 2021-05-11, updated 2022-10-05Version 2

This paper characterizes the annealed complexity of bipartite spherical spin glasses, both pure and mixed. This means we give exact variational formulas for the asymptotics of the expected numbers of critical points and of local minima. This problem was initially considered by [Auffinger, Chen 2014], who gave upper and lower bounds on this complexity. We find two surprising connections between pure bipartite and pure single-species spin glasses, which were studied by [Auffinger, Ben Arous, \v{C}ern\'y 2013]. First, the local minima of any pure bipartite model lie primarily in a low-energy band, similar to the single-species case. Second, for a more restricted set of pure $(p, q)$ bipartite models, the complexity matches exactly that of a pure $p + q$ single-species model.