Another proof of Gell-Mann and Low’s theorem
本文檔由 四悉地 分享于2018-11-05 21:31
The theorem by Gell-Mann and Low is a cornerstone in quantum field theory and zero-temperature many-body theory. The standard proof is based on Dyson’s timeordered expansion of the propagator; a proof based on exact identities for the time propagator is here given.