Thermal effects on saxion in supersymmetric model with Peccei-Quinn symmetry

We consider supersymmetric model with Peccei-Quinn symmetry and study effects of saxion on the evolution of the universe, paying particular attention to the effects of thermal bath. The axion multiplet inevitably couples to colored particles, which induces various thermal effects. In particular, (i) saxion potential is deformed by thermal effects, and (ii) coherent oscillation of the saxion dissipates via the interaction with hot plasma. These may significantly affect the evolution of the saxion in the early universe.