The Friedmann cosmological models: open, flat, and closed; matter and radiation dominated. The cosmological constant. Three degree blackbody radiation and its theoretical implications. Experimental tests in cosmology. Nucleosynthesis and galaxy formation. Anisotropic and inhomogeneous cosmologies: the Bianchi models, primarily Kasner and Type IX. GUTs in the very early universe: baryogenesis and phase transitions. Dark matter. Cosmic strings and magnetic monopoles. Inflationary models. Chaotic inflation. Future history and final state of the universe.pre-rec: PHYS 423, 625, and 630.