We are pleased to announce a Journal club by Toyokazu Sekiguchi.
* Title: Axion DM from topological defects
* Speaker: Toyokazu Sekiguchi (CTPU) (at KAIST Munji Campus)
* Date: 3:00~4:00 PM, 26 Nov 2015
* Abstract: We investigate the cosmological scenario where the Peccei-Quinn symmetry breaks after inflation. In this scenario, axionic cosmic strings and domain walls form and axions are abundantly produced from these topological defects. These axions contribute to cold dark matter in the present Universe. Employing the state of art field theoretic simulations of the topological defects, we update the estimation of the axion abundance. It is found that axions can be responsible for the cold dark matter in the mass range $m_a=(0.8−1.3)×10^−4$eV for the models with the domain wall number $N_DW=1$, and $m_a=(10^-4−10^−2)$eV with a mild tuning of parameters for the models with $N_{DW}$>1. We also discuss the possibility for near-future experiments to probe these mass ranges of axions.
* Reference:
http://arxiv.org/abs/1412.0789
We look forward to your participation in the Journal club.
Thank you.
Sincerely,
Sung Yeop Na