Fields that are completely decoupled from the inflaton still interact with gravitational strength interactions. Although these are very suppressed at low energies, a large number of them can have interesting effects on cosmological observables. We make a few observations in this regard, including i) how the scale dependence of the effective strength of gravity complicates the determination of the absolute energy scale of inflation, and ii) how the absence of observed non-Gaussianities (i.e. non-vanishing higher order correlation functions) in the cosmic microwave background can be used to place bounds on the number of hidden fields in the universe. We discuss the implications of the latter observation on various string/susy phenomenological scenarios of the early universe.
