Warm inflation in the adiabatic regime — a model, an existence proof for inflationary dynamics in quantum field theory Original Research Article

Warm inflation is examined in a multi-field model. Solutions are obtained for expansion e-folds and scalar density perturbations. Nonequilibrium dynamics is restricted to a regime that is displaced only slightly from thermal equilibrium and in which all macroscopic motion is adiabatic. In such a regime, nonequilibrium dynamics is well defined, provided macroscopic motions that displace the thermal equilibrium state occur sufficiently slow. The solution has adjustable parameters that permit observational consistency with respect to expansion e-folds and density perturbations in the full adiabatic regime, thus insuring a valid solution regime. For particle physics, the model is nonstandard since it requires a large number of fields, >104 . A particle physics/string interpretation of the model and solutions is discussed, which can accommodate the large field number requirement.