CHAOTIC INFLATION FROM A SCALAR FIELD IN NONCLASSICAL STATES - ART. NO. 103514

We study chaotic inflation driven by a real, massive, homogeneous mini mally coupled scalar field in a flat Robertson-Walker spacetime. The s emiclassical limit for gravity is considered, whereas the scalar field is treated quantum mechanically by the technique of invariants in ord er to also investigate the dynamics of the system for non-classical st ates of the latter. An inflationary stage is found to be possible for a large set of initial quantum states, obviously including the coheren t ones. States associated with a vanishing mean value of the field (su ch as the vacuum and thr: thermal) can also lead to inflation: however , for such states we cannot make a definitive prediction due to the im portance of higher order corrections during inflation. The results for the above coupled system are described and their corrections evaluate d perturbatively. [S0556-2821(98)02722-2].