Quantum Inflaton Dynamics
  We show that the quantum dynamics of a real scalar field for a large class of potentials in the symmetric Gaussian state, where the nonperturbative quantum contributions are taken into account, can be described equivalently by a two-dimensional nonlinear dynamical system with a definite angular momentum (U(1) charge of a complex theory). It is found that the Gaussian state with a nearly minimal uncertainty and a large quantum fluctuation, as an initial condition, naturally explains the most of the essential features of the early stage of the inflationary Universe. 
Dongsu Bak, Sang Pyo Kim, Sung Ku Kim, Kwang-Sup Soh, Jae Hyung Yee