Retarded thermal Green{close_quote}s functions and forward scattering amplitudes at two loops

Journal Article · Mon Nov 01 04:00:00 EST 1999 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.60.105008· OSTI ID:690768

Brandt, F T ^[1]; Das, A ^[2]; Frenkel, J ^[1]

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1. Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, SP 05315-970 (Brazil)
2. Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627-0171 (United States)

In this paper, we extend our earlier one loop analysis to two loops and give a simple diagrammatic description for the retarded Green{close_quote}s functions at finite temperature in terms of forward scattering amplitudes of on-shell thermal particles. We present a simple discussion, which can be easily generalized to any field theory, of the temperature dependent parts of the retarded two and three point functions in scalar field theory and QED. As an application of our result at two loops, we show how the infrared singularities in the thermal part of the retarded photon self-energy cancel in QED{sub 2} in the limit of vanishing electron mass. {copyright} {ital 1999} {ital The American Physical Society}

• OSTI ID: 690768
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 10 Vol. 60; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
FEYNMAN DIAGRAM
GREEN FUNCTION
LAGRANGIAN FIELD THEORY
PERTURBATION THEORY
QUANTUM ELECTRODYNAMICS
QUANTUM FIELD THEORY
SCATTERING
SCATTERING AMPLITUDES
SELF-ENERGY