Ultralight dark matter searches with KAGRA gravitational wave telescope

Abstract: Among various dark matter candidates, bosonic ultralight fields with masses below 1~eV are well motivated. Recently, a number of novel approaches have been put forward to search for ultralight dark matter candidates using laser interferometers at various scales. Those include our proposals to search for axion-like particles (ALPs) and vector fields with laser interferometric gravitational wave detectors. ALPs can be searched for by measuring the oscillating polarization rotation of laser light. Massive vector fields weakly coupled to the standard model sector can also be searched for by measuring the oscillating forces acting on the suspended mirrors of the interferometers. In this paper, the current status of the activities to search for such ultralight dark matter candidates using a gravitational wave detector in Japan, KAGRA, is reviewed. The analysis of data from KAGRA's observing run in 2020 to search for vector dark matter, and the installation of polarization optics to the arm cavity transmission ports of the interferometer to search for ALPs in future observing runs are underway.