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Late-time cosmological phase transitions: Particle-physics models and cosmic evolution

1992; American Physical Society; Volume: 46; Issue: 4 Linguagem: Inglês

10.1103/physrevd.46.1226

1538-4500

J. Frieman, Christopher T. Hill, Richard Watkins,

Particle physics theoretical and experimental studies

We describe a natural particle-physics basis for late-time phase transitions in the Universe. Such a transition can seed the formation of large-scale structure while leaving a minimal imprint upon the microwave background anisotropy. The key ingredient is an ultralight pseudo Nambu-Goldstone boson with an astronomically large (\ensuremath{\sim}kpc-Mpc) Compton wavelength. We analyze the cosmological signatures of and constraints upon a wide class of scenarios which do not involve domain walls. In addition to seeding structure, coherent ultralight bosons may also provide unclustered dark matter in a spatially flat universe, ${\ensuremath{\Omega}}_{\ensuremath{\varphi}}\ensuremath{\simeq}1$.