RESUMMATION IN A HOT SCALAR FIELD-THEORY

A resummed perturbative expansion is used to obtain the self-energy in the high-temperature g(2)phi(4) field-theory model up to order g4. From this the zero-momentum pole of the effective propagator is evaluated to determine the induced thermal mass and damping rate for the bosons in the plasma to order g3. The calculations are performed in the imaginary-time formalism and a simple diagrammatic analysis is used to identify the relevant diagrams at each order. Results are compared with similar real-time calculations found in the literature.