Nonclassical nature of thermal quantum states in the oscillating FRW Universe

摘要

We used coherent thermal and squeezed thermal vacuum states to represent the massive inflaton field in the semi-classical gravity; therefore, it would be useful to examine whether the field exhibits classical or nonclassical nature in the cosmological context. In the present article, we examine the non-classical nature of thermal quantum optical states in the cosmological context using Mandel's Q parameter.