Particle Production and Density Fluctuations of Non-classical Inflaton in Coherent Squeezed Vacuum State of Flat FRW Universe

We study non-classical inflaton, which is minimally coupled to the semiclassical gravity in FRW universe in Coherent Squeezed Vacuum State (CSVS). We determined Oscillatory phase of inflaton, power-law expansion, scale factor, density fluctuations, quantum fluctuations and particle production for CSVS. We obtained an estimated leading solution of scale factor in CSVS proportional to $t^{2/3}$ follow similar diversification as demonstrated by Semiclassical Einstein Equation (SCEE) of gravity in matter dominated universe. We also studied the validity of SCEE in CSVS. By determining the quantum fluctuation for CSVS validity of uncertainty relation for FRW Universe also computed. The results shows that Quantum fluctuations doesn't depend on coherent parameter $\Upsilon$ as uncertainty relation doesn't effected by the displacement of $\Upsilon$ in phase space. We study the production of particles in CSVS for oscillating massive inflaton in flat FRW universe.

Dhwani Gangal, Sudhava Yadav, K.K. Venkataratnam · 2024