The Strongly Coupled Polaron on the Torus: Quantum Corrections to the Pekar Asymptotics

We investigate the Fr"ohlich polaron model on a three-dimensional torus, and give a proof of the second-order quantum corrections to its ground-state energy in the strong-coupling limit. Compared to previous work in the confined case, the translational symmetry (and its breaking in the Pekar approximation) makes the analysis substantially more challenging.