2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/40641After recalling why dynamical adjustment mechanisms represent a particularly attractive possibility for solving the cosmological constant problem, we briefly discuss their intrinsic difficulties as summarized in Weinberg's no-go theorem. We then comment on some problems of the recently proposed `self-tuning' mechanism in 4+1 dimensions. Finally, we describe an alternative approach which uses the time-evolution of the universe to achieve a dynamical relaxation of the cosmological constant to zero.4 pages LaTeX, talk at PASCOS 2001, Chapel Hill, North Carolina, 10-15 April 2001High Energy Physics - Phenomenologytext