Regular Article - Theoretical Physics
Lagrangian perturbation theory: exact one-loop power spectrum in general dark energy models
School of Physics, Korea Institute for Advanced Study, Heogiro 85, Seoul, 130-722, Korea
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Accepted: 20 October 2014
Published online: 11 November 2014
Recently, we found that the correction for the Einstein–de Sitter (EdS) assumption on the one-loop matter power spectrum for general dark energy models using the standard perturbation theory is not negligible (Lee et al., arXiv:1407.7325, 2014). Thus, we investigate the same problem by obtaining the exact displacement vector and kernels up to the third order for the general dark energy models in the Lagrangian perturbation theory (LPT). Using these exact solutions, we investigate the present one-loop matter power spectrum in the CDM model with to obtain a % error correction compared to that obtained from the EdS assumption for the mode. If we consider the total matter power spectrum, the correction is only % for the same mode. It means that the EdS assumption is a good approximation for the CDM model in LPT theory. However, one can use this method for general models where the EdS assumption is improper.
© SIF and Springer-Verlag Berlin Heidelberg, 2014