2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/205283Applying the Thomas-Fermi approximation to renormalizable field theories, we construct ghost condensation models that are free of the instabilities associated with violations of the null-energy condition.9 pages, minor corrections, a reference added, the discussion on consistency of the Thomas-Fermi approximation expanded, to appear in JCAPGeneral Relativity and Quantum CosmologyAstrophysicsHigh Energy Physics - Phenomenologytext