  During its early evolution, the hot, dense Universe provided a laboratory for
probing fundamental physics at high energies. By studying the relics from those
early epochs, such as the light elements synthesized during primordial
nucleosynthesis when the Universe was only a few minutes old, and the relic,
cosmic microwave photons, last scattered when the protons, alphas, and
electrons (re)combined some 400 thousand years later, the evolution of the
Universe may be used to test the standard models of cosmology and particle
physics and to set constraints on proposals of physics beyond these standard
models.
