  We consider the long time behavior of solutions to scalar field models
appearing in the theory of cosmological inflation (oscillons) and cold dark
matter, in presence or absence of the cosmological constant. These models are
not included in standard mathematical literature due to their unusual
nonlinearities, which model different features to classical ones. Here we prove
that these models fit in the theory of dispersive decay by computing new
virials adapted to their setting. Several important examples, candidates to
model both effects are studied in detail.
