Blast-frozen dark matter and modulated density perturbations

First-order phase transitions (FOPTs) are ubiquitous in beyond the Standard Model physics and leave distinctive echoes in the history of early Universe. We consider a FOPT serving the well-motivated role of dark matter mass generation and present blast-frozen dark matter (BFDM), which transitions from radiation to nonrelativistic relic in a period much shorter than the corresponding Hubble time. Its cosmological imprint are strong oscillations in the dark matter density perturbations that seed structure formation on large and small scales. For a FOPT occurring not long before the matter-radiation equality, next-generation cosmological surveys bear a strong potential to discover BFDM and in turn establish the origin of dark matter mass.