Fast computation of non-linear power spectrum in cosmologies with massive neutrinos. (arXiv:2208.02791v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Noriega_H/0/1/0/all/0/1">Hernán E. Noriega</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aviles_A/0/1/0/all/0/1">Alejandro Aviles</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fromenteau_S/0/1/0/all/0/1">Sebastien Fromenteau</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vargas_Magana_M/0/1/0/all/0/1">Mariana Vargas-Magaña</a>
We compute 1-loop corrections to the redshift space galaxy power spectrum in
cosmologies containing additional scales, and hence kernels different from
Einstein-de Sitter (EdS). Specifically, our method is tailored for cosmologies
in the presence of massive neutrinos and some modified gravity models; in this
article we concentrate on the former case. The perturbative kernels have
contributions that we notice appear either from the logarithmic growth factor
$f(k,t)$, which is scale-dependent because of the neutrino free-streaming, or
from the failure of the commonly used approximation $f^2=Omega_m$. The latter
contributions make the computation of loop corrections quite slow, precluding
full-shape analyses for parameter estimation. However, we identify that the
dominant pieces of the kernels come from the growth factor, allowing us to
simplify the kernels but retaining the characteristic free-streaming scale
introduced by the neutrinos’ mass. Moreover, with this simplification one can
exploit FFTLog methods to speed up the computations even more. We validate our
analytical modeling and numerical method with halo catalogs extracted from the
Quijote simulations finding good agreement with the, a priori, known
cosmological parameters. We make public our Python code FOLPS$nu$ to compute
the redshift space power spectrum in a fraction of second. Code available at
https://github.com/henoriega/FOLPS-nu.
We compute 1-loop corrections to the redshift space galaxy power spectrum in
cosmologies containing additional scales, and hence kernels different from
Einstein-de Sitter (EdS). Specifically, our method is tailored for cosmologies
in the presence of massive neutrinos and some modified gravity models; in this
article we concentrate on the former case. The perturbative kernels have
contributions that we notice appear either from the logarithmic growth factor
$f(k,t)$, which is scale-dependent because of the neutrino free-streaming, or
from the failure of the commonly used approximation $f^2=Omega_m$. The latter
contributions make the computation of loop corrections quite slow, precluding
full-shape analyses for parameter estimation. However, we identify that the
dominant pieces of the kernels come from the growth factor, allowing us to
simplify the kernels but retaining the characteristic free-streaming scale
introduced by the neutrinos’ mass. Moreover, with this simplification one can
exploit FFTLog methods to speed up the computations even more. We validate our
analytical modeling and numerical method with halo catalogs extracted from the
Quijote simulations finding good agreement with the, a priori, known
cosmological parameters. We make public our Python code FOLPS$nu$ to compute
the redshift space power spectrum in a fraction of second. Code available at
https://github.com/henoriega/FOLPS-nu.
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