Abstract

Contributed Talk - Splinter Relativistic   (MW-2050)

Search for axion-like particles with strong gravitational lenses

Dominik Schwarz, Shivani Deshmuk, Aritra Basu, Ann Mao, Yuko Urakawa
Universität Bielefeld

Axion-like particles (ALPs) are among the leading candidates for dark matter. Axions and axion-like particles interact with light, which leads to the phenomenon of achromatic birefringence. In this presentation, we will show how strongly lensed polarised radio sources can be used to exploit the ALP-induced birefringence to search for ALP dark matter. We will report new upper limits from multi-band, multi-epoch spectra-polarimetric VLA observations of a single lens system. This new limit improves on the CAST experiment by an order of magnitude over a range of ultra-light masses and demonstrates the search potential of the method once more lense systems and many observational epochs are combined.