Nonlinear effects of dark energy clustering beyond the acoustic scales

DIANA L. LÓPEZ NACIR

Leiden

Workshop; Workshop on `Non-Linear Structure in the Modified Universe'; 2014

Lorentz Center

We extend a resummation method (which we call AP) to compute the total density power spectrum in models of quintessence with a vanishing speed of sound. For standard \LambdaCDM cosmologies, the method allows predictions with an accuracy at the few percent level beyond the range of scales where acoustic oscillations are present, therefore comparable to other, common numerical tools. Our approach indicates an approximate but valuable and simple relation between the power spectra for standard quintessence models and models where scalar field perturbations appear at all scales. This, in turn, provides an educated guess for the prediction of nonlinear growth in models with generic speed of sound, particularly valuable since no numerical results are yet available.