Date:
6. December 2013 - 11:30
Speaker:
Sacha Davidson (IPNL, Lyon U.)
The axion vs the WIMP
The QCD axion is a micro->milli eV boson arising in extensions of the Standard Model which solve the
"strong CP problem". It is consistent with astrophysical observations of the cooling timescale of stars.
Non-thermal production mechanisms in the early Universe allow the axions, despite their neutrino-scale
mass, to behave like Cold Dark Matter: their energy density redshifts like matter, and their density
fluctuations grow like CDM. I aim to review the above, and explore the question of how to distinguish
axions from WIMPs, in particular during non-linear stucture formation. Sadly, I have not an answer.