Abstract:
Under time-dependent background, some particles can become light and those particles are produced (in non-perturbative way). Such particle production takes important roles in the early universe because the background is changing during inflation. Also, the relaxion mechanism, a dynamical approach to fine-tuning problem, has a condition that particle production happens. In this talk, I discuss particle production of scalars and gauge bosons for relaxion and inflation. In particular, we investigate aspects of possible replacement of relaxion wiggle, new dissipative force of inflation, and reheating of relaxion.