A Model of Large Quintessence Isocurvature Fluctuations and Low CMB Quadrupole

Abstract

Based on quintessence models with anticorrelation between the quintessence fluctuations and adiabatic perturbations in the other matter components, we show that if the quintessence potential is sufficiently steep in the initial era, i.e., at the beginning of radiation dominated epoch, the quintessence fluctuations can be large enough to sufficiently suppress the CMB power spectrum at low multipoles without excess gravitational waves. The leaping kinetic term quintessence and the crossover quintessence models, can realize such steep potential at the initial stage, and therefore can give rise to a low CMB quadrupole as required by observations.