Thermal effective potential of the O(N) linear sigma model

The finite-temperature effective potential of the O(N) linear sigma model is studied, with emphasis on the implications for the investigation of hot hadron dynamics. The contributions from all the ''bubble diagrams'' are fully taken into account for arbitrary N; this also allows to address some long-standing issues concerning the use of non-perturbative approaches in (finite-temperature) field theory. (C) 1997 Elsevier Science B.V