Scale-Invariant Resummed Perturbation at Finite Temperatures. Auteur(s): Kneur J.-L., Pinto Marcus (Article) Publié: Physical Review Letters, vol. 116 p.031601 (2016) Texte intégral en Openaccess : Ref HAL: hal-01177137_v1 PMID 26849585 Ref Arxiv: 1507.03508 DOI: 10.1103/PhysRevLett.116.031601 WoS: 000368523200003 Ref. & Cit.: NASA ADS Exporter : BibTex | endNote 11 Citations Résumé: We use the scalar model with quartic interaction to illustrate how a nonperturbative variational technique combined with renormalization group (RG) properties efficiently resums perturbative expansions in thermal field theories. The resulting convergence and scale dependence of optimized thermodynamical quantities, here illustrated up to two-loop order, are drastically improved as compared to standard perturbative expansions, as well as to other related methods such as the screened perturbation or (resummed) hard-thermal-loop perturbation, that miss RG invariance (as we explain). Being very general and easy to implement, our method is a potential analytical alternative to dealing with the phase transitions of field theories such as thermal QCD. Commentaires: 5 pages, 1 figure |