Rest mass oscillation induced by scalar dark matter and its detection using space-based gravitational waves detector and classical tests of the equivalence principle

by Jordan Gué

Thursday 13 Feb 2025, 12:00 → 13:00 Europe/Madrid

IFAE Seminar Room (In-Person)

Abstract : Scalar ultralight dark matter (ULDM) candidates, such as dilatons and axions, would induce oscillatory motion of freely falling test masses via their coupling to Standard Model fields. This effect can be probed via classical and quantum tests of the equivalence principle, but also using space based gravitational waves (GW) detectors. In the first part of the talk, I will present a numerical study on the potential of LISA to detect such DM candidates, which specifically investigates whether LISA can decorrelate a scalar ULDM signal from a monochromatic GW. Using one year of realistic orbits for the spacecrafts and Bayesian methods, we find that LISA will indeed be able to discriminate between the two signals.
In the second part of the talk, I will focus on the coupling between axion dark matter and QCD, and how it can induce a non-zero static differential acceleration between test masses of different composition. I will present the result of the data analysis of the final released data from MICROSCOPE, to search for this effect. While no positive signal has been found, I will present a (preliminary) improved upper limit on the axion-gluon coupling, compared to existing laboratory bounds.