Hot. delta. expansion

Journal Article · Tue May 15 04:00:00 EDT 1990 · Physical Review, D (Particles Fields); (USA)

DOI:https://doi.org/10.1103/PhysRevD.41.3269· OSTI ID:6848230

Bender, C M ^[1]; Rebhan, A ^[2]

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1. Department of Physics, Washington University, St. Louis, Missouri 63130 (USA)
2. Institut fuer Theoretische Physik, Technische Universitaet Wien, Wiedner Hauptstrasse 8-10, A-1040 Vienna (Austria)

The {delta} expansion, a novel perturbative scheme for quantum field theories, is investigated in the case of finite temperatures. For the exactly solvable example of the large-{ital N} limit of massless scalar four-dimensional {phi}{sup 4} theory, the first two orders of the {delta} expansion are compared with ordinary perturbation theory which at finite temperature is infrared singular beyond one-loop order. The {delta} expansion gives results which are nonperturbative with respect to the coupling constant and which compare favorably with the exact solution. Most importantly, the {delta} series naturally solves the general infrared problem of perturbative high-temperature field theories.

• OSTI ID: 6848230
• Journal Information: Physical Review, D (Particles Fields); (USA), Journal Name: Physical Review, D (Particles Fields); (USA) Vol. 41:10; ISSN PRVDA; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

645400* -- High Energy Physics-- Field Theory
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COUPLING CONSTANTS
ELEMENTARY PARTICLES
FIELD THEORIES
INFRARED DIVERGENCES
MASSLESS PARTICLES
PERTURBATION THEORY
PHI4-FIELD THEORY
PROPAGATOR
QUANTUM FIELD THEORY
SCALAR FIELDS
TEMPERATURE DEPENDENCE