We summarize our recent results on the ground state energy of multi-polaron
systems. In particular, we discuss stability and existence of the thermodynamic
limit, and we discuss the absence of binding in the case of large Coulomb
repulsion and the corresponding binding-unbinding transition. We also consider
the Pekar-Tomasevich approximation to the ground state energy and we study
radial symmetry of the ground state density.Comment: Contribution to the proceedings of ICMP12, Aalborg, Denmark, August
6--11, 2012; 8 page
