Speaker
Description
Dark matter fermions interacting through an attractive force mediated by a light scalar can form bound structures already in the very early universe. We show that binaries composed of such dark matter halos can generate gravitational wave (GW) signals observable today, even when the individual halos are extremely light. Because the dark Yukawa interaction, which is much stronger than gravity, governs the dynamics of these systems, they can emit sizable GW signals at initially very high frequencies despite their low masses. As the universe expands, these signals are redshifted into frequency bands accessible to current and future GW detectors.
The resulting GW signatures exhibit distinctive features that can differentiate them from conventional astrophysical sources. Remarkably, even if only a small fraction of dark matter participates in such strong self-interactions, the associated GW signals may still be detectable. This opens a new avenue for probing self-interacting dark matter through gravitational wave observations.