DEMNUni: the clustering of large-scale structures in the presence of massive neutrinos

By E. Castorina, C. Carbone, J. Bel, E. Sefusatti, Klaus Dolag. 2015

154 citations recorded by the source corpus.

We analyse the clustering features of Large Scale Structures (LSS) in the presence of massive neutrinos, employing a set of large-volume, high-resolution cosmological N-body simulations, where neutrinos are treated as separate collisionless particles. The volume of 8 h-3 Gpc3, combined with a resolution of about 8×1010h-1M⊚ for the cold dark matter (CDM) component, represents a significant improvement over previous N-body simulations in massive neutrino cosmologies. In this work we focus, in the first place, on the analysis of nonlinear effects in CDM and neutrinos perturbations contributing to the total matter power spectrum. We show that most of the nonlinear evolution is generated exclusively by the CDM component. We therefore compare mildly nonlinear predictions from Eulerian Perturbation Theory (PT), and fully nonlinear prescriptions (HALOFIT) with the measurements obtained from the simulations. We find that accounting only for the nonlinear evolution of the CDM power spectrum allows to recover the total matter power spectrum with the same accuracy as the massless case. Indeed, we show that, the most recent version of the (HALOFIT) formula calibrated on ΛCDM simulations can be applied directly to the linear CDM power spectrum without requiring additional fitting parameters in the massive case. As a second step, we study the abundance and clustering properties of CDM halos, confirming that, in massive neutrino cosmologies, the proper definition of the halo bias should be made with respect to the cold rather than the total matter distribution, as recently shown in the literature. Here we extend these results to the redshift space, finding that, when accounting for massive neutrinos, an improper definition of the linear bias can lead to a systematic error of about 1-2 % in the determination of the linear growth rate from anisotropic clustering. This result is quite important if we consider that future spectroscopic galaxy surveys, as e.g. Euclid, are expected to measure the linear growth-rate with statistical errors less than about 3 % at z≲1.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/afd307adddb283705c104b6d9a29121f240eac7a

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Shi-Fan Chen
2. Mikhail Ivanov
3. Z. Vlah
4. O. Philcox
5. M. White
6. M. Simonovi'c
7. E. Castorina
8. A. Chudaykin

In Nuclear and High Energy Physics

1. O. Philcox
2. Mikhail Ivanov
3. M. Simonovi'c
4. A. Chudaykin
5. Z. Vlah
6. M. White
7. Shi-Fan Chen
8. E. Castorina

Citations in the corpus

• Nonlinear perturbation theory extension of the Boltzmann code CLASS (2020, methodology): “This prescription has been advocated on the basis of N-body simulations in [89, 90, 90–93]; besides, Refs.”
• A new analysis of galaxy 2-point functions in the BOSS survey, including full-shape information and post-reconstruction BAO (2021, methodology): “[72]) have sought to more exactly integrate the scale-dependent effects of massive neutrinos into LPT, in this work we will approximate the effect of neutrinos on galaxy clustering by using the “cb” prescription [73].”
• Redshift-space distortions in Lagrangian perturbation theory (2020, background): “It is well known that halos and galaxies are biased tracers of the dark matter and baryon fluids only [96–102], which implies the bias expansion presented in Section 2 will still be valid with the trivial replacement of the total matter field with the dark matter plus baryon one.”