2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/206482We demonstrate that power-like non-perturbative behavior of gluon and ghost propagators in infrared limit of Yang-Mills theories can provide at finite temperatures T a negative T^4-contribution to the pressure and energy density. Existence of mass gap implies then new relations between infrared critical exponents of gluon and ghost propagators.4 pages, RevTeX 4. Revision: title changed, references and new material added. Published versionHigh Energy Physics - PhenomenologyOther Condensed MatterHigh Energy Physics - LatticeHigh Energy Physics - Theorytext