2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/193900We outline the evaluation of the cosmological constant in the framework of the standard field-theoretical treatment of vacuum energy and discuss the relation between the vacuum energy problem and the gauge-group spontaneous symmetry breaking. We suggest possible extensions of the 't Hooft-Nobbenhuis symmetry, in particular, its complexification till duality symmetry and discuss the compatible implementation on gravity. We propose to use the discrete time-reflection transform to formulate a framework in which one can eliminate the huge contributions of vacuum energy into the effective cosmological constant and suggest that the breaking of time--reflection symmetry could be responsible for a small observable value of this constant.11 pages, more relevant refs, refining cutoff definition of cosmological constant + eq.for regularized pressure addedGeneral Relativity and Quantum CosmologyAstrophysicsHigh Energy Physics - Theorytext