skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: LUKEWARM DARK MATTER: BOSE CONDENSATION OF ULTRALIGHT PARTICLES

Journal Article · · Astrophysical Journal Letters
 [1];  [2];  [3];  [4]
  1. Department of Physics, Syracuse University, Syracuse, NY 13244 (United States)
  2. Department of Physics and Astronomy, 108 Lewis Hall, University of Mississippi, University, MS 38677 (United States)
  3. Department of Physics, 104 Davey Laboratory, Pennsylvania State University, University Park, PA 16802 (United States)
  4. Department of Arts and Sciences, Harris-Stowe State University, 3026 Laclede Avenue, St. Louis, MO 63103 (United States)

We discuss the thermal evolution and Bose-Einstein condensation of ultralight dark matter particles at finite, realistic cosmological temperatures. We find that if these particles decouple from regular matter before Standard Model particles annihilate, their temperature will be about 0.9 K. This temperature is substantially lower than the temperature of cosmic microwave background neutrinos and thus big bang nucleosynthesis remains unaffected. In addition, the temperature is consistent with WMAP 7-year+BAO+H0 observations without fine-tuning. We focus on particles of mass of m {approx} 10{sup -23} eV, which have Compton wavelength of galactic scales. Agglomerations of these particles can form stable halos and naturally prohibit small-scale structure. They avoid over-abundance of dwarf galaxies and may be favored by observations of dark matter distributions. We present numerical as well as approximate analytical solutions of the Friedmann-Klein-Gordon equations and study the cosmological evolution of this scalar field dark matter from the early universe to the era of matter domination. Today, the particles in the ground state mimic pressureless matter, while the excited state particles are radiation like.

OSTI ID:
21448726
Journal Information:
Astrophysical Journal Letters, Vol. 715, Issue 1; Other Information: DOI: 10.1088/2041-8205/715/1/L35; ISSN 2041-8205
Country of Publication:
United States
Language:
English