This book presents reviews and new findings in the field of the very early universe, where the interests of particle theorists and astrophysicists meet. Also, WIMP search experiments are reported. Contents: Cold Dark Matter Cosmology: Status and Open Questions (J R Primack); Review of Cosmological Parameters (W L Freedman); Relic Neutralinos: An Overview (A Bottino); Neutralino Proton Cross Section and Dark Matter Detection (R Arnowitt et al.); What is the Dark Matter of the Universe? (G L Kane); Axino OCo New Candidate for Cold Dark Matter (L Roszkowski); Signature for Signals from the Dark Universe (P Belli et al.); Limits on the WIMP-Nucleon Cross-Section from the Cryogenic Dark Matter Search (R W Schnee et al.); Large N Cosmology (S W Hawking); Observational Constraints on Models of Inflation (D Lyth); Atmospheric and Solar Neutrino Masses and Abelian Flavor Symmetry (K Choi); Current Experimental Status of Neutrino Oscillation (K Nakamura); Tunneling Phenomena in Cosmology: Some Fundamental Problems (M Yoshimura); The Cosmological Constant and the Brane World Scenario (H P Nilles); Color Superconductivity and Compact Star Cooling (D K Hong); and other papers. Readership: Graduate students, academics and researchers in high energy physics, astrophysics, astronomy and cosmology."