2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/108761We show that convexity of the effective action follows from its functional flow equation. Our analysis is based on a new, spectral representation. The results are relevant for the study of physical instabilities. We also derive constraints for convexity-preserving regulators within general truncation schemes including proper-time flows, and bounds for infrared anomalous dimensions of propagators.4 pages, 3 figuresHigh Energy Physics - Theorytext