Cosmology with Ultralight Pseudo Nambu-Goldstone Bosons
Abstract
We explore the cosmological implications of an ultralight pseudo Nambu-Goldstone boson. With global spontaneous symmetry breaking scale f~=1018 GeV and explicit breaking scale comparable to Mikheyev-Smirnov-Wolfenstein neutrino masses, M~10-3 eV, such a field, which acquires a mass mφ~M2/f~H0, would currently dominate the energy density of the Universe. The field acts as an effective cosmological constant before relaxing into a condensate of nonrelativistic bosons. Such a model can reconcile dynamical estimates of the density parameter, Ωm~0.2, with a spatially flat universe, yielding H0t0~=1 consistent with limits from gravitational lens statistics.
- Publication:
-
Physical Review Letters
- Pub Date:
- September 1995
- DOI:
- 10.1103/PhysRevLett.75.2077
- arXiv:
- arXiv:astro-ph/9505060
- Bibcode:
- 1995PhRvL..75.2077F
- Keywords:
-
- Astrophysics
- E-Print:
- 15 pages (including 2 figs.), uuencoded compressed postscript