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Accurate predictions for the non-linear matter power spectrum are needed to confront theory with observations in current and near future weak lensing and galaxy clustering surveys. We propose a computationally cheap method to create an…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-01 Hans Winther , Santiago Casas , Marco Baldi , Kazuya Koyama , Baojiu Li , Lucas Lombriser , Gong-Bo Zhao

We introduce an emulator approach to predict the non-linear matter power spectrum for broad classes of beyond-$\Lambda$CDM cosmologies, using only a suite of $\Lambda$CDM $N$-body simulations. By including a range of suitably modified…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-02 Benjamin Giblin , Matteo Cataneo , Ben Moews , Catherine Heymans

Based on a suite of state-of-the-art high-resolution $N$-body simulations, we revisit the so-called halofit model (Smith et al. 2003) as an accurate fitting formula for the nonlinear matter power spectrum. While the halofit model has been…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Ryuichi Takahashi , Masanori Sato , Takahiro Nishimichi , Atsushi Taruya , Masamune Oguri

The spatial curvature ($\Omega_K$) of the Universe is one of the most fundamental quantities that could give a link to the early universe physics. In this paper we develop an approximate method to compute the nonlinear matter power…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-19 Ryo Terasawa , Ryuichi Takahashi , Takahiro Nishimichi , Masahiro Takada

We consider cosmological models in which dark matter feels a fifth force mediated by the dark energy scalar field, also known as coupled dark energy. Our interest resides in estimating forecasts for future surveys like Euclid when we take…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-02 Santiago Casas , Luca Amendola , Marco Baldi , Valeria Pettorino , Adrian Vollmer

We present a general method to compute the nonlinear matter power spectrum for dark energy and modified gravity scenarios with percent-level accuracy. By adopting the halo model and nonlinear perturbation theory, we predict the reaction of…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-16 Matteo Cataneo , Lucas Lombriser , Catherine Heymans , Alexander Mead , Alexandre Barreira , Sownak Bose , Baojiu Li

To effectively exploit large-scale structure surveys, we depend on accurate and reliable predictions of non-linear cosmological structure formation. Tools for efficient and comprehensive computational modelling are therefore essential to…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-07 Benjamin Bose , Matteo Cataneo , Tilman Tröster , Qianli Xia , Catherine Heymans , Lucas Lombriser

Redshift space distortions of the matter density power spectrum carry information on the growth rate of cosmic structure but require accurate modeling of nonlinear and velocity effects on the density field. We test and advance the…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-19 Alberto Vallinotto , Eric V. Linder

The growth of large-scale structure, together with the geometrical information of cosmic expansion history and cosmological distances, can be used to obtain constraints on the spatial curvature of the universe that probes the early universe…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-23 Ryo Terasawa , Ryuichi Takahashi , Takahiro Nishimichi , Masahiro Takada

The 3D matter power spectrum, $P_{\delta}(k,z)$ is a fundamental quantity in the analysis of cosmological data such as large-scale structure, 21cm observations, and weak lensing. Existing computer models (Boltzmann codes) such as CLASS can…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-09 Arrykrishna Mootoovaloo , Andrew H. Jaffe , Alan F. Heavens , Florent Leclercq

We provide a new fitting formula of the matter bispectrum in the nonlinear regime calibrated by high-resolution cosmological $N$-body simulations of $41$ cold dark matter ($w$CDM, $w=$ constant) models around the Planck 2015 best-fit…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-10 Ryuichi Takahashi , Takahiro Nishimichi , Toshiya Namikawa , Atsushi Taruya , Issha Kayo , Ken Osato , Yosuke Kobayashi , Masato Shirasaki

Rapid and accurate evaluation of the nonlinear matter power spectrum, $P(k)$, as a function of cosmological parameters and redshift is of fundamental importance in cosmology. Analytic approximations provide an interpretable solution, yet…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-24 Deaglan J. Bartlett , Benjamin D. Wandelt , Matteo Zennaro , Pedro G. Ferreira , Harry Desmond

Computing the matter power spectrum, $P(k)$, as a function of cosmological parameters can be prohibitively slow in cosmological analyses, hence emulating this calculation is desirable. Previous analytic approximations are insufficiently…

We use the recently developed Kinetic Field Theory (KFT) for cosmic structure formation to show how non-linear power spectra for cosmic density fluctuations can be calculated in a mean-field approximation to the particle interactions. Our…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-23 Matthias Bartelmann , Johannes Dombrowski , Sara Konrad , Elena Kozlikin , Robert Lilow , Carsten Littek , Christophe Pixius , Felix Fabis

Near-future cosmological observations targeted at investigations of dark energy pose stringent requirements on the accuracy of theoretical predictions for the clustering of matter. Currently, N-body simulations comprise the only viable…

Astrophysics · Physics 2010-08-25 Katrin Heitmann , Martin White , Christian Wagner , Salman Habib , David Higdon

This paper presents an analytical formula that closely approximates the fully nonlinear power spectrum of matter fluctuations for redshift $z\approx 5$ to 0 over a wide range of cosmologically interesting flat models with varying matter…

Astrophysics · Physics 2009-10-30 Chung-Pei Ma

We study the prediction of the Effective Field Theory of Large Scale Structures (EFTofLSS) for the matter power spectrum at different redshifts. In previous work, we found that the two-loop prediction can match the nonlinear power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-27 Simon Foreman , Leonardo Senatore

The mysterious nature of the dark sector of the $\Lambda$CDM model is one of the main motivators behind the study of alternative cosmological models. A central quantity of interest for these models is the matter power spectrum, which…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-11 Renate Mauland , Hans A. Winther , Cheng-Zong Ruan

We present new fitting functions for the velocity divergence auto- and cross-power spectra, $P_{\theta\theta}(k)$ and $P_{\delta\theta}(k)$, calibrated on gravity-only $N$-body simulations. By applying the Evolution Mapping framework, we…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-15 Matteo Esposito , Ariel G. Sánchez , Julien Bel , Andrés N. Ruiz

We present methods for emulating the matter power spectrum by combining information from cosmological $N$-body simulations at different resolutions. An emulator allows estimation of simulation output by interpolating across the parameter…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-17 Ming-Feng Ho , Simeon Bird , Christian R. Shelton
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