Paper

Tree-Level Bispectrum in the Effective Field Theory of Large-Scale Structure extended to Massive Neutrinos

de Belsunce, Roger, Senatore, Leonardo

2019

Overview

We compute the tree-level bispectrum of dark matter in the presence of massive neutrinos in the mildly non-linear regime in the context of the effective field theory of large-scale structure (EFTofLSS). For neutrinos, whose typical free streaming wavenumber (\\(k_{\\rm fs}\\)) is longer than the non-linear scale (\\(k_{\\mathrm{NL}}\\)), we solve a Boltzmann equation coupled to the effective fluid equation for dark matter. We solve perturbatively the coupled system by expanding in powers of the neutrino density fraction (\\(f_{\\nu}\\)) and the ratio of the wavenumber of interest over the non-linear scale (\\(k/k_{\\mathrm{NL}}\\)) and add suitable counterterms to remove the dependence from short distance physics. For equilateral configurations, we find that the total-matter tree-level bispectrum is approximately \\(16f_{\\nu}\\) times the dark matter one on short scales (\\(k > k_{\\rm fs}\\)). The largest contribution stems from the back-reaction of massive neutrinos on the dark matter growth factor. On large scales (\\(k < k_{\\rm fs}\\)) the contribution of neutrinos to the bispectrum is smaller by up to two orders of magnitude.

• Publisher: Cornell University Library, arXiv.org
• Subject: Boltzmann transport equation / Dark matter / Dependence / Field theory / Growth factors / Neutrinos / Wavelengths