Renormalization of self-consistent approximation schemes at finite temperature. II. Applications to the sunset diagram

@article{Hees2001RenormalizationOS,
  title={Renormalization of self-consistent approximation schemes at finite temperature. II. Applications to the sunset diagram},
  author={Hendrik van Hees and Joern Knoll},
  journal={Physical Review D},
  year={2001},
  volume={65},
  pages={105005}
}
The theoretical concepts for the renormalization of self-consistent Dyson resummations, deviced in the first paper of this series, are applied to first example cases for the $\phi^4$-theory. Besides the tadpole (Hartree) approximation as a novel part the numerical solutions are presented which includes the sunset self-energy diagram into the self-consistent scheme based on the $\Phi$-derivable approximation or 2PI effective action concept. 
73 Citations

Figures from this paper

Techniques for calculations with nPI effective actions

We consider a symmetric scalar theory with quartic coupling in 2- and 3- dimensions and compare the self-consistent 4-point vertex obtained from the 4PI effective action with the Bethe-Salpeter

2PI effective action for gauge theories: Renormalization

We discuss the application of two-particle-irreducible (2PI) functional techniques to gauge theories, focusing on the issue of non-perturbative renormalization. In particular, we show how to

O(N) linear sigma model at finite temperature beyond the Hartree approximation

We study the O(N) linear sigma model with spontaneous symmetry breaking, using a Hartree-like ansatz with a classical field and variational masses. We go beyond the Hartree approximation by including

Renormalization of the 4PI effective action using the functional renormalization group

Techniques based on $n$-particle irreducible effective actions can be used to study systems where perturbation theory does not apply. The main advantage, relative to other non-perturbative continuum
...