1209.6018 (Wei-Jie Fu)

Hubbard Model in the Two-particle Irreducible Effective Action Formalism    [PDF]

Wei-Jie Fu

The two-particle irreducible (2PI) effective action theory is employed in the two-dimensional Hubbard model. We obtain the corresponding quantum 2PI effective action after the original classic action of the Hubbard model is bosonized. In our actual calculations, the 2PI effective action is expanded to three loops, in which the leading order (LO) and next-to-leading order (NLO) quantum fluctuations are included. We also obtain the LO and NLO contributions to the fermion and boson self-energies. Numerical calculations on a lattice are also performed in our approaches.

View original: http://arxiv.org/abs/1209.6018