2001/07/10 by Eric Braaten, E. Petitgirard, Emmanuel Petitgirard · 3 citations
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Cosmology and Gravitation Theories #High-Energy Particle Collisions Research #hep-ph
paper · pdf · doi:10.1103/physrevd.65.085039
published as Phys.Rev. D65 (2002) 085039 · 57 pages, 10 figures
arxiv created 2001/07/10 · openalex publication_date 2002/04/09 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We develop a systematic method for solving the 3-loop Φ-derivable approximation to the thermodynamics of the massless ϕ4 field theory. The method involves expanding sum-integrals in powers of g2 and m/T, where g is the coupling constant, m is a variational mass parameter, and T is the temperature. The problem is reduced to one with the single variational parameter m by solving the variational equations order-by-order in g2 and m/T. At the variational point, there are ultraviolet divergences of order g6 that cannot be removed by any renormalization of the coupling constant. We define a finite thermodynamic potential by truncating at 5th order in g and m/T. The associated thermodynamic functions seem to be perturbatively stable and insensitive to variations in the renormalization scale.