Constraining the Inflationary Equation of State

Abstract. We explore possible constraints on the inflationary equation state: p = wρ. While w must be close to −1 for those modes that contribute to the observed power spectrum, for those modes currently out of experimental reach, the constraints on w are much weaker, with only w < −1/3 as an a priori requirement. We find, however, that limits on the reheat temperature and the inflationary energy scale constrain w further, though there is still ample parameter space for a vastly different (accelerating) equation of state between the end of quasi-de Sitter inflation and the beginning of the radiation-dominated era. In the event that such an epoch of acceleration could be observed, we review the consequences for the primordial power spectrum. ArXiv ePrint: 1007.3511 ar X i