1996/10/23 by Ian D. Lawrie, I. D. Lawrie, D. B. McKernan · 3 citations
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Boltzmann equation #Classical mechanics #Cosmology and Gravitation Theories #Dissipative system #Non-equilibrium thermodynamics #Perturbation (astronomy) #Perturbation theory (quantum mechanics) #Physics #Propagator #Quantum Electrodynamics and Casimir Effect #Quantum electrodynamics #Quantum mechanics #Quasiparticle #Scalar field #Thermal #Thermal equilibrium #Thermal quantum field theory #Thermodynamics #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.55.2290
published as Phys.Rev. D55 (1997) 2290-2297 · 15 pages using RevTeX; 2 figures in 1 Postscript file; Submitted to Phys. Rev. D
arxiv created 1996/10/23 · openalex publication_date 1997/02/15 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Real-time perturbation theory is formulated for complex scalar fields away from thermal equilibrium in such a way that dissipative effects arising from the absorptive parts of loop diagrams are approximately resummed into the unperturbed propagators. Low order calculations of physical quantities then involve quasiparticle occupation numbers which evolve with the changing state of the field system, in contrast with standard perturbation theory, where these occupation numbers are frozen at their initial values. The evolution equation of the occupation numbers can be cast approximately in the form of a Boltzmann equation. Particular attention is given to the effects of a nonzero chemical potential, and it is found that the thermal masses and decay widths of quasiparticle modes are different for particles and antiparticles.