Phase transition during inflation

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Abstract

Symmetry plays important roles in particle physics. In the Standard Model and beyond, phase transition associated with symmetry breaking may occur in the early universe. We will discuss an unexplored possibility that phase transition occurs during inflation rather than after inflation. We first argue that phase transition may naturally occur during inflation, triggered by slow-roll dynamics of an inflation field or a spectator field. We then discuss two applications of phase transition during inflation: enhanced axion dark matter production and gravitational-waves with a characteristic spectrum and anisotropy.

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