Dissipation in equations of motion of scalar fields

Abstract

The methods of non-equilibrium quantum field theory are used to investigate the possibility of representing dissipation in the equation of motion for the expectation value of a scalar field by a friction term, such as is commonly included in phenomenological inflaton equations of motion. A sequence of approximations is exhibited which reduces the non-equilibrium theory to a set of local evolution equations. However, the adiabatic solution to these evolution equations which is needed to obtain a local equation of motion for the expectation value is not well defined; nor, therefore, is the friction coefficient. Thus, a non-equilibrium treatment is essential, even for a system that remains close to thermal equilibrium, and the formalism developed here provides one means of achieving this numerically.

17 pages, 5 figures

References in corpus (3)

• Nonequilibrium time evolution of the spectral function in quantum field theory
• Affinity for Scalar Fields to Dissipate
• Friction in inflaton equations of motion

Cited by in corpus (9)

• Warm Inflation and its Microphysical Basis
• Dynamics of Interacting Scalar Fields in Expanding Space-Time
• The warm inflation story
• Fluctuation-dissipation dynamics of cosmological scalar fields
• Thermal effects on slow-roll dynamics
• Spotted Inflation
• Entropy production and curvature perturbation from dissipative curvatons
• Aspects of warm-flat directions
• Numerical investigation of friction in inflaton equations of motion