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相关论文: Nonlinear structure formation in Nonlocal Gravity

200 篇论文

We study a spherical, self-gravitating fluid model, which finds applications in cosmic structure formation. We argue that since the system features nonlinearity and gravity-induced dispersion, the emergence of solitons becomes possible. We…

斑图形成与孤子 · 物理学 2024-02-21 G. N. Koutsokostas , S. Sypsas , O. Evnin , T. P. Horikis , D. J. Frantzeskakis

Cosmic structures at small non-linear scales $k>L\sim 0.2 h $ Mpc$^{-1}$ have an impact on the longer (quasi-)linear wavelengths with $k<L$ via non-linear UV-IR mode coupling. We evaluate this effect for a $\Lambda$CDM universe applying the…

宇宙学与河外天体物理 · 物理学 2015-05-19 Kari Enqvist , Gerasimos Rigopoulos

We examine the nonlinear structure of gravitationally collapsed objects that form in our simulations of wavelike cold dark matter ($\psi$DM), described by the Schr\"{o}dinger-Poisson (SP) equation with a particle mass $\sim 10^{-22} {\rm…

The interacting dark energy (IDE) model, which considers the interaction between dark energy and dark matter, provides a natural mechanism to alleviate the coincidence problem and can also relieve the observational tensions under the…

宇宙学与河外天体物理 · 物理学 2022-02-09 Yun Liu , Shihong Liao , Xiangkun Liu , Jiajun Zhang , Rui An , Zuhui Fan

We present a detailed study of the redshift evolution of dark matter halo structural parameters in a LambdaCDM cosmology. We study the mass and redshift dependence of the concentration, shape and spin parameter in Nbody simulations spanning…

宇宙学与河外天体物理 · 物理学 2015-05-19 J. C. Muñoz-Cuartas , A. V. Macciò , S. Gottlöber , A. A. Dutton

We present "sheet+release" simulations that reliably follow the evolution of dark matter structure at and below the dark matter free-streaming scale, where instabilities in traditional N-body simulations create a large population of…

宇宙学与河外天体物理 · 物理学 2021-11-03 Jens Stücker , Raul E. Angulo , Oliver Hahn , Simon D. M. White

We test cosmological models of structure formation using the rotation curve of the nearest spiral galaxy, M31, determined using a recent deep, full-disk 21-cm imaging survey smoothed to 466 pc resolution. We fit a tilted ring model to the…

宇宙学与河外天体物理 · 物理学 2015-05-14 Edvige Corbelli , Silvio Lorenzoni , René A. M. Walterbos , Robert Braun , David A. Thilker

This work investigates the impact of different Modified Gravity (MG) models on the large-scale structures (LSS) properties in relation to the cosmic web (CW), using N-body simulations of f(R) and nDGP models. We analyse the impact of the MG…

宇宙学与河外天体物理 · 物理学 2024-10-28 Suhani Gupta , Simon Pfeifer , Punyakoti Ganeshaiah Veena , Wojciech A. Hellwing

We investigate the effect of long-range scalar interactions in dark matter (DM) models of cosmic structure formation with a particular focus on the formation times of haloes. Utilising $N$-body simulations with $512^3$ DM particles we show…

宇宙学与河外天体物理 · 物理学 2010-09-20 Wojciech A. Hellwing , Steffen R. Knollmann , Alexander Knebe

Theoretical differences in the growth of structure offer the possibility that we might distinguish between modified gravity theories of dark energy and \LambdaCDM. A significant impediment to applying current and prospective large scale…

天体物理学 · 物理学 2008-11-26 Istvan Laszlo , Rachel Bean

We study the growth of large scale structure in two recently proposed non-standard cosmological models: the brane induced gravity model of Dvali, Gabadadze and Porrati (DGP) and the Cardassian models of Freese and Lewis. A general formalism…

天体物理学 · 物理学 2009-11-07 T. Multamaki , E. Gaztanaga , M. Manera

We propose a simple, nonlocal modification to general relativity (GR) on large scales, which provides a model of late-time cosmic acceleration in the absence of the cosmological constant and with the same number of free parameters as in…

广义相对论与量子宇宙学 · 物理学 2018-03-30 Valeri Vardanyan , Yashar Akrami , Luca Amendola , Alessandra Silvestri

We present constraints on the flat $\Lambda$CDM cosmological model through a joint analysis of galaxy abundance, galaxy clustering and galaxy-galaxy lensing observables with the Kilo-Degree Survey. Our theoretical model combines a flexible…

In this work we systematically study the linear and nonlinear structure formation in chameleon theories of modified gravity, using a generic parameterisation which describes a large class of models using only 4 parameters. For this we have…

宇宙学与河外天体物理 · 物理学 2013-05-24 Philippe Brax , Anne-C. Davis , Baojiu Li , Hans A. Winther , Gong-Bo Zhao

We study the phase-space structure of a dark-matter halo formed in a high resolution simulation of a Lambda CDM cosmology. Our goal is to quantify how much substructure is left over from the inhomogeneous growth of the halo, and how it may…

天体物理学 · 物理学 2009-09-25 Amina Helmi , Simon D. M. White , Volker Springel

New corrections to General Relativity are considered in the context of modified $f(R)$ gravity, that satisfy cosmological and local gravity constraints. The proposed models behave asymptotically as $R-2\Lambda$ at large curvature and show…

广义相对论与量子宇宙学 · 物理学 2022-01-13 L. N. Granda

We compute the critical density of collapse for spherically symmetric overdensities in a class of f(R) modified gravity models. For the first time we evolve the Einstein, scalar field and non-linear fluid equations, making the minimal…

宇宙学与河外天体物理 · 物理学 2013-11-26 Michael Kopp , Stephen A. Appleby , Ixandra Achitouv , Jochen Weller

We explore the effects of background cosmology on large scale structures with non-spherical symmetry by using the concept of quasi-equilibrium which allows certain internal properties (e.g. angular velocity) of the bodies to change with…

广义相对论与量子宇宙学 · 物理学 2008-11-26 A. Balaguera-Antolinez , M. Nowakowski

The statistical properties of dark matter halos, the building blocks of cosmological observables associated with structure in the universe, offer many opportunities to test models for cosmic acceleration, especially those that seek to…

天体物理学 · 物理学 2009-10-02 Fabian Schmidt , Marcos Lima , Hiroaki Oyaizu , Wayne Hu

Massive cosmological neutrinos suppress the Large-Scale Structure (LSS) in the Universe by smoothing the cosmic over-densities, and hence structure formation is delayed relative to that in the standard Lambda-Cold Dark Matter ($\Lambda$CDM)…

宇宙学与河外天体物理 · 物理学 2022-04-04 Hiu Wing Wong , Ming-chung Chu