  We study some aspects of cosmologies in 5D models with one infinite extra
dimension. Matter is confined to the brane, gravity extends to the bulk. Models
with positive and negative tension of the brane are considered. Cosmological
evolution of the 4D world is described by warped solutions of the generalized
Friedmann equation. Cosmological solutions on the brane are obtained with the
input of the present-time observational cosmological parameters. We estimate
the age of the Universe and abundance of ${}^4 He$ produced in primordial
nucleosynthesis in different models. Using these estimates we find constraints
on dimensionless combinations of the 5D gravitational scale, scale of the warp
factor and coupling at the 4D curvature term in the action.

Cosmology and Nongalactic Astrophysics