Journal Club

Seminar Room

Monday 19th of May, 2014

Axions: Bose Einstein Condensate or Classical Field?

The axion is a motivated dark matter candidate, so it would be interesting to find features in Large Scale Structures specific to axion dark matter. Such features were proposed for a Bose Einstein condensate of axions, leading to confusion in the literature (to which I contributed) about whether axions condense due to their gravitational interactions. This note argues that the Bose Einstein condensation of axions is a red herring: the axion dark matter produced by the misalignment mechanism is already a classical field, which has the distinctive features attributed to the axion condensate (BE condensates are described as classical fields). The rate at which gravity could condense the cold axion particles produced from strings is estimated to be negligeable.
Comments: 11 pages, 1 figure
Subjects: High Energy Physics - Phenomenology (hep-ph)
Cite as: arXiv:1405.1139 [hep-ph]
  (or arXiv:1405.1139v1 [hep-ph] for this version)
Presented by: many of us