Halo White Dwarfs and Galactic Structure -- Old Ultracool White Dwarfs as Cosmological Probes -- Number Counts of White Dwarfs: The Impact of GAIA -- Influence of Metallicity in the Determination of the Age of Halo White Dwarfs -- Cool Halo White Dwarfs from GSCII -- Dark Halo Baryons not in Ancient White Dwarfs? -- The White Dwarf Population in the 2QZ and Sloan Surveys -- White Dwarfs and Cataclysmic Variables in the FBS -- Spectroscopic and Photometric Observations of White Dwarfs in Globular Clusters -- The Core/Envelope Symmetry in Pulsating White Dwarf Stars -- A Search for Variability in Cool White Dwarf Stars -- Study of the Galactic Bulge Using New Planetary Nebulae Discovered on the AAO/UKST H? Survey -- Type Ia Supernovae -- Type Ia Supernovae and Cosmology -- The Progenitors of Type Ia Supernovae -- Surveys for Double Degenerate Progenitors of Supernovae Type Ia -- Population Synthesis for Progenitors of Type Ia Supernovae -- How Far Can We Trust Type Ia Supernovae as Standard Candles? -- Kirshner on White Dwarfs, Supernovae, and Cosmology -- Cataclysmic Variables and White Dwarf Accretion -- Accretion in Cataclysmic Variable Stars -- White Dwarfs in Cataclysmic Variables: Probes of Accretion History -- Intermediate Polars in Low States -- Chemical Abundances of White Dwarfs in Cataclysmic Variables -- AM CVn Stars in the UCT CCD CV Survey -- Photometric Observations of Cataclysmic Variables with the 1.5-m Telescope at the TÜBITAK National Observatory (TUG): V2275 Cyg, RW UMi, PX And and FO Per -- The Possible Identification of Two Hibernating Novae -- Evidence for Large Superhumps in TX Col and V4742 Sgr -- Concluding Remarks -- Understanding the Ultimate Fate of the Universe.The emphasis on white dwarf stars and cosmology arises from the most recent advances in cosmological and galactic structure research in which white dwarf stars are playing a very prominent role. Examples are Type Ia supernovae (i.e. white dwarf supernovae), the origin and evolution of the universe, the age of the galactic disk, cosmochronology using white dwarfs in globular clusters and galactic clusters, and the physics of accretion onto compact (very dense) stars. As an assisting guide to the reader, we have included, by invitation, comprehensive review articles in each of the four major areas of the book, white dwarf supernovae, cosmology, accretion physics and galactic structure. The reviews include introductory material that they build upon. The book is suitable and most useful to advanced undergraduates, graduate students and scientific professionals (e.g. astronomers, astrophysicists, cosmologists, physicists).