Young filaments in active centers.

Topics in nuclear astrophysics are considered in terms of cosmology, grand unified theories, pair production and annihilation in the universe, the Big Bang, supernovae, and processes which occur in observed stellar objects. Specific attention is given to nuclear and particle physics of the early universe, quarks, solar neutrinos, and the nucleosynthesis of light and of heavy elements. A model is presented of a thermonuclear runaway, along with analyses of the structure of neutron stars, nuclear explosions on neutron stars, and a cold Big Bang with small black holes. Consideration is directed toward the transfer of laboratory results to astrophysical problems, and radio measurements of He abundances are discussed. Finally, the emission of neutrinos from electron-positron annihilation, the first order phase transition of a vacuum and baryon number domain structure of the Universe, and the neutron lifetime are explored.