Workshop on Very Light Dark Matter 2021

Session

Tuesday AM

Sep 28, 2021, 10:00 AM

Online

Conveners

Tuesday AM

• Naoya Kitajima

20. Axion in antiferromagnetic insulators

Koji Ishiwata

9/28/21, 10:00 AM

Invited

21. Axion dark matter search with magnons

Asuka Ito

9/28/21, 10:40 AM

Invited

The axion provides a solution for the strong CP problem and is one of the leading candidates for dark matter. In this talk, we propose an axion detection scheme based on quantum nondemolition detection of magnons, i.e., quanta of collective spin excitations in a ferromagnetic crystal. Furthermore, we give an upper limit on the coupling constant between an axion and an electron for a certain...

22. Axion clouds may survive the perturbative tidal interaction over the early inspiral phase of black hole binaries

Takuya Takahashi

9/28/21, 11:30 AM

Axion forms a cloud around a rotating black hole (BH) by superradiant instability. On the other hand, considering the cloud associated with a BH in a binary system, tidal interaction depletes the cloud in some cases during the inspiral phase. To clarify the condition that clouds avoid disappearing, we made the exhaustive study of cloud depletion numerically in a wide parameter range for equal...

23. An analytic model for the sub-galactic matter power spectrum in fuzzy dark matter halos

Hiroki Kawai

9/28/21, 11:45 AM

Fuzzy dark matter (FDM) is one of the promising alternative dark matter candidates to cold dark matter. The quantum clumps, which is a unique structure of FDM, can be seen in halos in cosmological FDM simulations. In this talk, we first provide our analytic model of the sub-galactic matter power spectrum originating from quantum clumps in FDM halos. Then we show a result of a comparison...

43. DANCE: Searching for Axion-like particle dark matter with optical bow-tie ring cavity

Hiroki Fujimoto

9/28/21, 12:00 PM

DANCE stands for Dark matter Axion search with riNg Cavity Experiment, and aims to detect the axion-like particle (ALP) dark matter by using laser interferometric techniques. ALPs interact with photons slightly and cause the rotational oscillation of linearly polarized light. The bow-tie ring cavity of DANCE can enhance the amplitude of the rotational oscillation by extending the effective...