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相关论文: Modelling the matter bispectrum at small scales in…

200 篇论文

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…

宇宙学与河外天体物理 · 物理学 2020-06-10 Ryuichi Takahashi , Takahiro Nishimichi , Toshiya Namikawa , Atsushi Taruya , Issha Kayo , Ken Osato , Yosuke Kobayashi , Masato Shirasaki

We compare higher order gravity models to observational constraints from magnitude-redshift supernova data, distance to the last scattering surface of the CMB, and Baryon Acoustic Oscillations. We follow a recently proposed systematic…

宇宙学与河外天体物理 · 物理学 2014-11-20 Jacob Moldenhauer , Mustapha Ishak

It is well established that maximizing the information extracted from upcoming and ongoing stage-IV weak-lensing surveys requires higher-order summary statistics that complement the standard two-point statistics. In this work, we focus on…

宇宙学与河外天体物理 · 物理学 2024-08-02 Christopher T. Davies , Joachim Harnois-Déraps , Baojiu Li , Benjamin Giblin , César Hernández-Aguayo , Enrique Paillas

We explore observational constraints on possible deviations from Newtonian gravity by means of large-scale clustering of galaxies. We measure the power spectrum and the bispectrum of Sloan Digital Sky Survey galaxies and compare the result…

天体物理学 · 物理学 2008-12-18 Akihito Shirata , Yasushi Suto , Chiaki Hikage , Tetsuya Shiromizu , Naoki Yoshida

We study the effect of modified gravity on weak lensing in a class of scalar-tensor theory that includes $f(R)$ gravity as a special case. These models are designed to satisfy local gravity constraints by having a large scalar-field mass in…

天体物理学 · 物理学 2009-06-23 Shinji Tsujikawa , Takayuki Tatekawa

We propose a new framework for testing gravity using cluster observations, which aims to provide an unbiased constraint on modified gravity models from Sunyaev Zel'dovich (SZ) and X-ray cluster counts and the cluster gas fraction, among…

宇宙学与河外天体物理 · 物理学 2018-05-10 Myles A. Mitchell , Jian-hua He , Christian Arnold , Baojiu Li

Clustering of large-scale structure provides significant cosmological information through the power spectrum of density perturbations. Additional information can be gained from higher-order statistics like the bispectrum, especially to…

宇宙学与河外天体物理 · 物理学 2015-03-09 Marcel Schmittfull , Tobias Baldauf , Uroš Seljak

Measurements of redshift space distortions (RSD) provide a means to test models of gravity on large-scales. We use mock galaxy catalogues constructed from large N-body simulations of standard and modified gravity models to measure galaxy…

宇宙学与河外天体物理 · 物理学 2019-02-27 César Hernández-Aguayo , Jiamin Hou , Baojiu Li , Carlton M. Baugh , Ariel G. Sánchez

We test the imprint of f(R) modified gravity on the halo mass function, using N-body simulations and a theoretical model developed in (Kopp et al. 2013). We find a very good agreement between theory and simulations. We extend the…

宇宙学与河外天体物理 · 物理学 2016-05-25 Ixandra Achitouv , Marco Baldi , Ewald Puchwein , Jochen Weller

The bispectrum, being sensitive to non-Gaussianity and mode coupling of cosmological fields induced by non-linear gravitational evolution, serves as a powerful probe for detecting deviations from General Relativity (GR). The signatures of…

宇宙学与河外天体物理 · 物理学 2025-09-17 Sukhdeep Singh Gill

We present a perturbative treatment of nonlinear galaxy clustering in the context of the cubic Galileon modified gravity model, in terms of 2nd order Lagrangian Perturbation theory and an extension of ellipsoidal collapse that includes…

宇宙学与河外天体物理 · 物理学 2022-10-14 Yanling Song , Chiara Moretti , Pierluigi Monaco , Bin Hu

Modified gravity theories have richer observational consequences for large-scale structure than conventional dark energy models, in that different observables are not described by a single growth factor even in the linear regime. We examine…

天体物理学 · 物理学 2009-02-20 Bhuvnesh Jain , Pengjie Zhang

The combination of GR and the Standard Model disagrees with numerous observations on scales from our Solar System up. In the concordance model of cosmology, these contradictions are removed or alleviated by the introduction of three…

广义相对论与量子宇宙学 · 物理学 2012-01-10 Glenn D. Starkman

We use a suite of high-resolution $N$-body simulations and state-of-the-art perturbation theory to improve the code halofit, which predicts the nonlinear matter power spectrum. We restrict attention to parameters in the vicinity of the…

宇宙学与河外天体物理 · 物理学 2019-04-09 Robert E. Smith , Raul E. Angulo

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…

宇宙学与河外天体物理 · 物理学 2020-01-01 Hans Winther , Santiago Casas , Marco Baldi , Kazuya Koyama , Baojiu Li , Lucas Lombriser , Gong-Bo Zhao

We perform N-body simulations for $f(T)$ gravity using the ME-Gadget code, in order to investigate for the first time the structure formation process in detail. Focusing on the power-law model, and considering the model-parameter to be…

宇宙学与河外天体物理 · 物理学 2022-10-12 Yiqi Huang , Jiajun Zhang , Xin Ren , Emmanuel N. Saridakis , Yi-Fu Cai

We study Modified Gravity (MG) theories by modelling the redshifted matter power spectrum in a spherical Fourier-Bessel (sFB) basis. We use a fully non-linear description of the real-space matter power-spectrum and include the lowest-order…

宇宙学与河外天体物理 · 物理学 2016-01-27 Dipak Munshi , Geraint Pratten , Patrick Valageas , Peter Coles , Philippe Brax

We use measurements from the Planck satellite mission and galaxy redshift surveys over the last decade to test three of the basic assumptions of the standard model of cosmology, $\Lambda$CDM: the spatial curvature of the universe, the…

宇宙学与河外天体物理 · 物理学 2016-01-20 Shadab Alam , Shirley Ho , Alessandra Silvestri

We extend the scale-dependent Gaussian Streaming Model (GSM) to produce analytical predictions for the anisotropic redshift-space correlation function for biased tracers in modified gravity models. Employing the Convolution Lagrangian…

宇宙学与河外天体物理 · 物理学 2020-02-03 Georgios Valogiannis , Rachel Bean , Alejandro Aviles

This note includes results of a study of stationary spherically symmetric ``dark holes'', objects merging central black holes and peripheral scalar graviton dark haloes arising in the framework of the modified gravity -- the quartet-metric,…

广义相对论与量子宇宙学 · 物理学 2025-07-15 Yu. F. Pirogov , O. V. Zenin