2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/192587It is shown that a well-known relation between entropy of a system and its energy spectrum being applied to the early universe determines the present vacuum energy and the time scale on which this energy can manifest itself. Given the present vacuum energy, the relation imposes a constraint on the initial inflationary state.3 pages, no figures; journal version: new title and minor corrections added; journal-ref addedGeneral Relativity and Quantum Cosmologytext