Mixed Dark Matter

A theory of dark matter which was promising up to the late 1990s.

"Mixed" dark matter is also called Hot + Cold Dark Matter. Hot Dark matter has only one known form - neutrinos, although other forms are speculated to exist. Cosmologically important dark matter is now believed to be pure Cold Dark Matter. However, in the early 1990s the power spectrum of fluctuations in the galaxy clustering did not agree entirely with the predictions for a standard cosmology built around pure Cold Dark Matter. Mixed Dark Matter with a composition of about 80% cold and 20% hot (neutrinos) was investigated and found to agree better with observations. This model was made obsolete by the discovery in 1998 of the acceleration of universal expansion, which eventually led to the Dark Energy + Dark Matter paradigm of this decade.

Famous quotes containing the words mixed, dark and/or matter:

    To brew up an adult, it seems that some leftover childhood must be mixed in; a little unfinished business from the past periodically intrudes on our adult life, confusing our relationships and disturbing our sense of self.
    Roger Gould (20th century)

    I’ve seen things you people wouldn’t believe. Attack ships on fire off the shoulder of Orion. I watched seabeams glitter in the dark near the Tennhauser Gate. All those moments will be lost in time like tears in rain. Time to die.
    David Webb Peoples, U.S. screenwriter, and Ridley Scott. Roy Batty, Blade Runner, final words before dying—as an android he had a built-in life span that expired (1982)

    This great kindness pervades Chekhov’s literary work, but it is not a matter of program or of literary message with him, but simply the natural coloration of his talent.
    Vladimir Nabokov (1899–1977)