Nonlinear power spectrum in the presence of massive neutrinos: Perturbation theory approach, galaxy bias, and parameter forecasts

Shun Saito; Masahiro Takada; Atsushi Taruya

doi:10.1103/physrevd.80.083528

Perturbation theory approach to predict the covariance matrices of the galaxy power spectrum and bispectrum in redshift space

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1940 ◽

2020 ◽

Vol 497 (2) ◽

pp. 1684-1711 ◽

Cited By ~ 6

Author(s):

Naonori S Sugiyama ◽

Shun Saito ◽

Florian Beutler ◽

Hee-Jong Seo

Keyword(s):

Perturbation Theory ◽

Power Spectrum ◽

Shot Noise ◽

Signal To Noise Ratio ◽

Covariance Matrices ◽

Theory Approach ◽

Cross Covariance ◽

The Galaxy ◽

The Cross ◽

Non Gaussian

ABSTRACT In this paper, we predict the covariance matrices of both the power spectrum and the bispectrum, including full non-Gaussian contributions, redshift space distortions, linear bias effects, and shot-noise corrections, using perturbation theory (PT). To quantify the redshift-space distortion effect, we focus mainly on the monopole and quadrupole components of both the power and bispectra. We, for the first time, compute the 5- and 6-point spectra to predict the cross-covariance between the power and bispectra, and the autocovariance of the bispectrum in redshift space. We test the validity of our calculations by comparing them with the covariance matrices measured from the MultiDark-Patchy mock catalogues that are designed to reproduce the galaxy clustering measured from the Baryon Oscillation Spectroscopic Survey Data Release 12. We argue that the simple, leading-order PT works because the shot-noise corrections for the Patchy mocks are more dominant than other higher order terms we ignore. In the meantime, we confirm some discrepancies in the comparison, especially of the cross-covariance. We discuss potential sources of such discrepancies. We also show that our PT model reproduces well the cumulative signal-to-noise ratio of the power spectrum and the bispectrum as a function of maximum wavenumber, implying that our PT model captures successfully essential contributions to the covariance matrices.

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Clustering in massive neutrino cosmologies via Eulerian Perturbation Theory

Journal of Cosmology and Astroparticle Physics ◽

10.1088/1475-7516/2021/11/028 ◽

2021 ◽

Vol 2021 (11) ◽

pp. 028

Author(s):

Alejandro Aviles ◽

Arka Banerjee ◽

Gustavo Niz ◽

Zachary Slepian

Keyword(s):

Perturbation Theory ◽

Power Spectrum ◽

Effective Field ◽

Tree Level ◽

Accurate Approximation ◽

Bias Parameter ◽

Wave Numbers ◽

Massive Neutrinos ◽

Correct Estimation ◽

The One

Abstract We introduce an Eulerian Perturbation Theory to study the clustering of tracers for cosmologies in the presence of massive neutrinos. Our approach is based on mapping recently-obtained Lagrangian Perturbation Theory results to the Eulerian framework. We add Effective Field Theory counterterms, IR-resummations and a biasing scheme to compute the one-loop redshift-space power spectrum. To assess our predictions, we compare the power spectrum multipoles against synthetic halo catalogues from the QUIJOTE simulations, finding excellent agreement on scales k ≲ 0.25 h Mpc-1. One can obtain the same fitting accuracy using higher wave-numbers, but then the theory fails to give a correct estimation of the linear bias parameter. We further discuss the implications for the tree-level bispectrum. Finally, calculating loop corrections is computationally costly, hence we derive an accurate approximation wherein we retain only the main features of the kernels, as produced by changes to the growth rate. As a result, we show how FFTLog methods can be used to further accelerate the loop computations with these reduced kernels.

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Perturbation theory approach for the power spectrum: from dark matter in real space to massive haloes in redshift space

Journal of Cosmology and Astroparticle Physics ◽

10.1088/1475-7516/2012/11/029 ◽

2012 ◽

Vol 2012 (11) ◽

pp. 029-029 ◽

Cited By ~ 28

Author(s):

Héctor Gil-Marín ◽

Christian Wagner ◽

Licia Verde ◽

Cristiano Porciani ◽

Raul Jimenez

Keyword(s):

Dark Matter ◽

Perturbation Theory ◽

Power Spectrum ◽

Real Space ◽

Theory Approach

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Accelerating Large-Scale-Structure data analyses by emulating Boltzmann solvers and Lagrangian Perturbation Theory

Open Research Europe ◽

10.12688/openreseurope.14310.1 ◽

2021 ◽

Vol 1 ◽

pp. 152

Author(s):

Giovanni Arico' ◽

Raul Angulo ◽

Matteo Zennaro

Keyword(s):

Perturbation Theory ◽

Power Spectrum ◽

Large Scale ◽

Theoretical Models ◽

Large Scale Structure ◽

Scale Structure ◽

Matter Power Spectrum ◽

Linear Spectrum ◽

Massive Neutrinos ◽

Cold Matter

The linear matter power spectrum is an essential ingredient in all theoretical models for interpreting large-scale-structure observables. Although Boltzmann codes such as CLASS or CAMB are very efficient at computing the linear spectrum, the analysis of data usually requires 104-106 evaluations, which means this task can be the most computationally expensive aspect of data analysis. Here, we address this problem by building a neural network emulator that provides the linear theory (total and cold) matter power spectrum in about one millisecond with ≈0.2%(0.5%) accuracy over redshifts z ≤ 3 (z ≤ 9), and scales10-4 ≤ k [h Mpc-1] < 50. We train this emulator with more than 200,000 measurements, spanning a broad cosmological parameter space that includes massive neutrinos and dynamical dark energy. We show that the parameter range and accuracy of our emulator is enough to get unbiased cosmological constraints in the analysis of a Euclid-like weak lensing survey. Complementing this emulator, we train 15 other emulators for the cross-spectra of various linear fields in Eulerian space, as predicted by 2nd-order Lagrangian Perturbation theory, which can be used to accelerate perturbative bias descriptions of galaxy clustering. Our emulators are specially designed to be used in combination with emulators for the nonlinear matter power spectrum and for baryonic effects, all of which are publicly available at http://www.dipc.org/bacco.

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On the road to per cent accuracy – III. Non-linear reaction of the matter power spectrum to massive neutrinos

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz3189 ◽

2019 ◽

Vol 491 (3) ◽

pp. 3101-3107 ◽

Cited By ~ 4

Author(s):

M Cataneo ◽

J D Emberson ◽

D Inman ◽

J Harnois-Déraps ◽

C Heymans

Keyword(s):

Power Spectrum ◽

Cold Dark Matter ◽

New Physics ◽

Model Reaction ◽

Matter Power Spectrum ◽

Non Linear ◽

Cent Level ◽

Massive Neutrinos ◽

On The Road ◽

Total Matter

ABSTRACT We analytically model the non-linear effects induced by massive neutrinos on the total matter power spectrum using the halo model reaction framework of Cataneo et al. In this approach, the halo model is used to determine the relative change to the matter power spectrum caused by new physics beyond the concordance cosmology. Using standard fitting functions for the halo abundance and the halo mass–concentration relation, the total matter power spectrum in the presence of massive neutrinos is predicted to per cent-level accuracy, out to $k=10 \,{ h}\,{\rm Mpc}^{-1}$. We find that refining the prescriptions for the halo properties using N-body simulations improves the recovered accuracy to better than 1 per cent. This paper serves as another demonstration for how the halo model reaction framework, in combination with a single suite of standard Λ cold dark matter (ΛCDM) simulations, can recover per cent-level accurate predictions for beyond ΛCDM matter power spectra, well into the non-linear regime.

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