2006/01/31 by F. T. Brandt, Fernando T. Brandt, Ashok Das +4 · 1 citation
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Quantum Mechanics and Applications #Quantum, superfluid, helium dynamics #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.73.065010
published as Phys.Rev.D73:065010,2006 · 13 pages, 4 figures. Revised version (minor changes) accepted for publication in Phys. Rev. D
arxiv created 2006/02/09 · openalex publication_date 2006/03/09 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Using the mixed space representation, we extend our earlier analysis to the case of Dirac and gauge fields and show that in the absence of a chemical potential, the finite temperature Feynman diagrams can be related to the corresponding zero temperature graphs through a thermal operator. At nonzero chemical potential we show explicitly in the case of the fermion self-energy that such a factorization is violated because of the presence of a singular contact term. Such a temperature dependent term which arises only at finite density and has a quadratic mass singularity cannot be related, through a regular thermal operator, to the fermion self-energy at zero temperature which is infrared finite. Furthermore, we show that the thermal radiative corrections at finite density have a screening effect for the chemical potential leading to a finite renormalization of the potential.