2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/148274At the simple example of a massless scalar field propagating in the static background we study the resummed expressions for the effective action at zero and finite temperature that are free from a usual sickness of the effective action induced by massless particles.7 pages, BI-TP 93/38 (revised)High Energy Physics - Theorytext