Asteroid-mass soliton as the dark matter-baryon coincidence solution

by Prof. Sinya Kanemura (U. Osaka)

Tuesday 10 Mar 2026, 16:30 → 18:30 Asia/Tokyo

A238 (Department of Physics, Faculty of Science)

Nontopological solitons formed during first-order phase transitions can
serve as macroscopic dark matter candidates, with their stability ensured
by a charge asymmetry traditionally assumed to originate from baryogenesis.
We discuss the possibility that solitogenesis after baryogenesis makes the
solitons a coincident dark matter candidate, providing new explanations for
the coincidence problem between baryon and dark matter energy densities. We
derive a novel and robust conclusion; asteroid-mass coincident soliton dark
matter is always accompanied by detectable gravitational waves observable
by LISA, μAres, and Theia, etc., providing a new candidate beyond
primordial black holes in this mass window. Additionally, we propose a
simple neutrino-ball scenario that addresses baryon asymmetry, dark matter,
and neutrino masses, featuring new particles below the electroweak scale
and correlated observable signals, including lensing, gravitational waves,
and soliton evaporation or collisions.