Role of scalar field in the formation of structure in the universe

A scalar field approach to the Jeans mass calculation is discussed. Considering a massive scalar field arbitrarily coupled to a gravitational background, the stress-energy tensor expectation values are computed in a coherent state. The density matrix is used to represent the expectation values. The energy density and pressure associated with the density perturbations are evaluated. Using these results, the exact expressions for the Jeans length and Jeans mass are evaluated