3rd Symposium on Prospects in the Physics of Discrete Symmetries | |
Thermal field theory to all orders in gradient expansion | |
Millington, Peter^1 ; Pilaftsis, Apostolos^2 | |
Consortium for Fundamental Physics, School of Mathematics and Statistics, University of Sheffield, Sheffield S3 7RH, United Kingdom^1 | |
Consortium for Fundamental Physics, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom^2 | |
关键词: Evolution equations; Non-markovian evolutions; Particle number density; Perturbation series; Perturbation theory; Quasi-particle approximation; Statistical distribution function; Time evolution equations; | |
Others : https://iopscience.iop.org/article/10.1088/1742-6596/447/1/012071/pdf DOI : 10.1088/1742-6596/447/1/012071 |
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来源: IOP | |
【 摘 要 】
We present a new perturbative formulation of non-equilibrium thermal field theory, based upon non-homogeneous free propagators and time-dependent vertices. The resulting time-dependent diagrammatic perturbation series are free of pinch singularities without the need for quasi-particle approximation or effective resummation of finite widths. After arriving at a physically meaningful definition of particle number densities, we derive master time evolution equations for statistical distribution functions, which are valid to all orders in perturbation theory and all orders in a gradient expansion. For a scalar model, we make a loopwise truncation of these evolution equations, whilst still capturing fast transient behaviour, which is found to be dominated by energy-violating processes, leading to non-Markovian evolution of memory effects.
【 预 览 】
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Thermal field theory to all orders in gradient expansion | 1008KB | download |