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We present a new numerical scheme to treat the non-linear evolution of cosmological power spectra. Governing equations for matter power spectra have been previously derived by a non-perturbative technique with closure approximation.…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-30 Takashi Hiramatsu , Atsushi Taruya

Based on the multi-point propagator expansion, we present resummed perturbative calculations for cosmological power spectra and correlation functions in the context of modified gravity. In a wide class of modified gravity models that have a…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-17 Atsushi Taruya , Takahiro Nishimichi , Francis Bernardeau , Takashi Hiramatsu , Kazuya Koyama

Building upon the recent pioneering work by Mazenko and by Das and Mazenko, we develop a microscopic, non-equilibrium, statistical field theory for initially correlated canonical ensembles of classical microscopic particles obeying…

Statistical Mechanics · Physics 2019-04-08 Matthias Bartelmann , Felix Fabis , Daniel Berg , Elena Kozlikin , Robert Lilow , Celia Viermann

We present results for the cosmic non-linear density-fluctuation power spectrum based on the analytical formalism developed in [1] which allows us to study cosmic structure formation based on Newtonian particle dynamics in phase-space. This…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 Tristan Daus , Elena Kozlikin

Perturbation theory of large-scale structures of the Universe at next-to-leading order and next-to-next-to-leading order provides us with predictions of cosmological statistics at sub-percent level in the mildly non-linear regime. Its use…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-08 Ken Osato , Takahiro Nishimichi , Atsushi Taruya , Francis Bernardeau

In this work we present a nonparametric approach, which works on minimal assumptions, to reconstruct the cosmic expansion of the Universe. We propose to combine a locally weighted scatterplot smoothing method and a simulation-extrapolation…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-20 Ariadna Montiel , Ruth Lazkoz , Irene Sendra , Celia Escamilla-Rivera , Vincenzo Salzano

In a previous paper (part I), the mathematical properties of the cosmic microwave background radiation power spectrum which presents oscillations were discussed. Here, we discuss the physical interpretation: a power spectrum with…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-28 Martin Lopez-Corredoira

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

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

The galaxy power spectrum is now a well-known tool of precision cosmology. In addition to the overall shape, baryon oscillations and the small-scale suppression of power by massive neutrinos capture complimentary information on cosmological…

Astrophysics · Physics 2009-11-10 Asantha Cooray

We present the BACCO project, a simulation framework specially designed to provide highly-accurate predictions for the distribution of mass, galaxies, and gas as a function of cosmological parameters. In this paper, we describe our main…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-04 Raul E. Angulo , Matteo Zennaro , Sergio Contreras , Giovanni Aricò , Marcos Pellejero-Ibañez , Jens Stücker

Nonlinear gravitational evolution induces strong nonlinearities in the observed cosmological density fields, leading to positive off-diagonal correlations in the power spectrum covariance. This has caused the information saturation in the…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-29 Shi-Hui Zang , Hong-Ming Zhu

We calculate the power spectrum of density fluctuations in the statistical non-equilibrium field theory for classical, microscopic degrees of freedom to first order in the interaction potential. We specialise our result to cosmology by…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-07 Matthias Bartelmann , Felix Fabis , Daniel Berg , Elena Kozlikin , Robert Lilow , Celia Viermann

We present an analytic model for the fully nonlinear power spectrum P and bispectrum Q of the cosmological mass density field. The model is based on physical properties of dark matter halos, with the three main model inputs being analytic…

Astrophysics · Physics 2009-06-16 Chung-Pei Ma , J. N. Fry

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

We discuss a method of calculating the key cosmological parameters on the basis of a selected scale factor by using exact solutions of the background equations. We specify the formulas for calculating the power spectrum, the spectral…

General Relativity and Quantum Cosmology · Physics 2017-04-19 Sergey V. Chervon , Igor V. Fomin

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

We study the non-linear evolution of baryon acoustic oscillations in the matter power spectrum and correlation function from the improved perturbation theory (PT). Based on the framework of renormalized PT, we apply the {\it closure…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-29 Atsushi Taruya , Takahiro Nishimichi , Shun Saito , Takashi Hiramatsu

We describe an approximate statistical model for the sample variance distribution of the non-linear matter power spectrum that can be calibrated from limited numbers of simulations. Our model retains the common assumption of a multivariate…

Cosmological probes pose an inverse problem where the measurement result is obtained through observations, and the objective is to infer values of model parameters which characterize the underlying physical system -- our Universe. Modern…

Instrumentation and Methods for Astrophysics · Physics 2019-05-21 Timur Takhtaganov , Zarija Lukic , Juliane Mueller , Dmitriy Morozov
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