PUB - Publikationen an der Universität Bielefeld

We find the best-fit cosmological parameters for a scenario of inflation withonly the sufficient amount of accelerated expansion for the $\lambda\phi^4$potential. While for the simplest scenario of chaotic inflation all observableprimordial fluctuations cross the Hubble horizon during the slow-roll epoch,for the scenario of just-enough inflation the slow-roll conditions are violatedat the largest length scales. Performing a numerical mode-by-mode integrationfor the perturbations on the largest scales and comparing the predictedanisotropies of the cosmic microwave background to results from the WMAP 7yrdata analysis, we find the initial conditions in agreement with currentcosmological data. In contrast to the simplest chaotic model for the quarticpotential, the just-enough inflation scenario is not ruled out. Although thisscenario naturally gives rise to a modification of the first multipoles, for aquartic potential it cannot explain the lack of power at the largest angularscales.