The Early Universe has become the standard reference on forefront topics in cosmology, particularly the early history of the Universe. Subjects covered include primordial nucleosynthesis, baryogenesis, phase transitions, inflation, dark matter, and galaxy formation, as well as relics such as axions, neutrinos, and monopoles, and speculations about the Universe at the Planck time. The book includes more than ninety figures, as well as a five-page update discussing recent developments such as the COBE results.