Interacting quantum fields in de Sitter spacetime

We study the vacuum zero point energy associated to an interacting scalar field with an arbitrary mass and conformal coupling in a dS background. Employing a dimensional regularization scheme, we calculate the regularized zero point energy density, pressure and the trace of the energy momentum tensor. It is shown that the classical relation for the vacuum stress energy tensor receives anomalous quantum correction which depends on the mass and the conformal coupling does not hold. We calculate the density contrast associated to the vacuum zero point energy indicating an inhomogeneous and nonperturbative distribution of the zero point energy. Finally, we calculate the skewness associated to the distribution of the zero point energy and pressure and show that they are highly non-Gaussian.