Upper bounds on the charge susceptibility of many-electron systems coupled to the quantized radiation field
arXiv:1405.0112
Abstract
We extend the Kubo-Kishi theorem concerning the charge susceptibility of the Hubbard model in the following way: (i) The electron-photon interaction is taken into account. (ii) Not only on-site but also general Coulomb repulsion is considered.
15 pages, V2:Minor corrections