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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

Taking advantage of the unprecedented statistical power of upcoming cosmic shear surveys will require exquisite knowledge of the matter power spectrum over a wide range of scales. Analytical methods can achieve such precision only up to…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-23 Matteo Cataneo

Model-independent tests of gravity with cosmology are important when testing extensions to the standard cosmological model. To maximise the impact of these tests one requires predictions for the matter power spectrum on non-linear scales.…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-18 Sankarshana Srinivasan , Daniel B Thomas , Richard Battye

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

Model-independent constraints on modified gravity models hitherto exist mainly on linear scales. A recently developed formalism presented a consistent parameterisation that is valid on all scales. Using this approach, we perform…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-15 Sankarshana Srinivasan , Daniel B Thomas , Francesco Pace , Richard Battye

We present numerical measurements of the power spectrum response function of the gravitational growth of cosmic structures, defined as the functional derivative of the nonlinear spectrum with respect to the linear counterpart, based on…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-20 Takahiro Nishimichi , Francis Bernardeau , Atsushi Taruya

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

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

We propose an alternative approach to the construction of fitting functions to the nonlinear matter power spectrum extracted from $N$-body simulations based on the relative matter power spectrum $\delta(k,a)$, defined as the fractional…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-18 Steen Hannestad , Yvonne Y. Y. Wong

The rapidly increasing statistical power of cosmological imaging surveys requires us to reassess the regime of validity for various approximations that accelerate the calculation of relevant theoretical predictions. In this paper, we…

Understanding nonlinear structure formation is crucial for fully exploring the data generated by stage IV surveys, requiring accurate modelling of the power spectrum. This is challenging for deviations from $\Lambda$CDM, but we must ensure…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-14 Pedro Carrilho , Karim Carrion , Benjamin Bose , Alkistis Pourtsidou , Juan Carlos Hidalgo , Lucas Lombriser , Marco Baldi

We present a specific prescription for the calculation of cosmological power spectra, exploited here at two-loop order in perturbation theory (PT), based on the multi-point propagator expansion. In this approach power spectra are…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Atsushi Taruya , Francis Bernardeau , Takahiro Nishimichi , Sandrine Codis

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 present the first MCMC-derived constraints on the parameters of the Large Scale Structure (LSS) bootstrap, a model-independent framework that captures deviations from $\Lambda$CDM using symmetry arguments alone. Focusing on modifications…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-14 Giorgia Biselli , Marco Marinucci , Guido D'Amico , Massimo Pietroni

Year 1 results of the Legacy Survey of Space and Time (LSST) will provide tighter constraints on small-scale cosmology, beyond the validity of linear perturbation theory. This heightens the demand for a computationally affordable…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-27 Jonathan Gordon , Bernardo F. de Aguiar , João Rebouças , Guilherme Brando , Felipe Falciano , Vivian Miranda , Kazuya Koyama , Hans A. Winther

Nonlinear effects are crucial in order to compute the cosmological matter power spectrum to the accuracy required by future generation surveys. Here, a new approach is presented, in which the power spectrum, the bispectrum and higher order…

Astrophysics · Physics 2009-11-13 Massimo Pietroni

We present a novel approach to test the consistency of the cosmological models with multiband CMB data using a nonparametric approach. In our analysis we calibrate the REACT (Risk Estimation and Adaptation after Coordinate Transformation)…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Amir Aghamousa , Arman Shafieloo

We extend the resummation method of Anselmi & Pietroni (2012) to compute the total density power spectrum in models of quintessence characterized by a vanishing speed of sound. For standard $\Lambda$CDM cosmologies, this resummation scheme…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Stefano Anselmi , Diana López Nacir , Emiliano Sefusatti

Limited-Angle Computed Tomography (LACT) is a challenging inverse problem where missing angular projections lead to incomplete sinograms and severe artifacts in the reconstructed images. While recent learning-based methods have demonstrated…

Image and Video Processing · Electrical Eng. & Systems 2025-07-09 Jiaqi Guo , Santiago López-Tapia

We propose a new approximated expression for non-linear Dark Matter power spectrum much beyond BAO scales. The proposed expression agrees with the result of N-body simulation with the accuracy better than 2 % up to k=1.0 [h/Mpc] and k=0.7…

General Relativity and Quantum Cosmology · Physics 2012-12-03 Naonori S. Sugiyama , Toshifumi Futamase
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