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We use two high resolution CDM simulations to show that (i) when clusters of galaxies form the infall pattern of matter is not random but shows clear features which are correlated in time; (ii) in addition, the infall patterns are…

Astrophysics · Physics 2007-05-23 J. M. Colberg , S. D. M. White , A. Jenkins , F. R. Pearce

We investigate two dark energy cosmological models (i.e., the $\Lambda$CDM and $\phi$CDM models) with massive neutrinos assuming two different neutrino mass hierarchies in both the spatially flat and non-flat scenarios, where in the…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-15 Yun Chen , Bharat Ratra , Marek Biesiada , Song Li , Zong-Hong Zhu

Despite the astonishing success of standard $\Lambda$CDM cosmology, there is mounting evidence for a tension with observations at small and intermediate scales. We introduce a simple model where both cold dark matter (DM) and sterile…

High Energy Physics - Phenomenology · Physics 2014-08-01 Torsten Bringmann , Jasper Hasenkamp , Joern Kersten

Much effort has been devoted to making large and more accurate models, but relatively little has been put into understanding which examples are benefiting from the added complexity. In this paper, we demonstrate and analyze the surprisingly…

Machine Learning · Computer Science 2022-02-16 Taman Narayan , Heinrich Jiang , Sen Zhao , Sanjiv Kumar

Consistency relations between growth of structure and expansion history observables exist for any physical explanation of cosmic acceleration, be it a cosmological constant, scalar field quintessence, or a general component of dark energy…

Astrophysics · Physics 2010-04-15 Michael J. Mortonson , Wayne Hu , Dragan Huterer

There is a growing literature on reasoning by large language models (LLMs), but the discussion on the uncertainty in their responses is still lacking. Our aim is to assess the extent of confidence that LLMs have in their answers and how it…

Computation and Language · Computer Science 2024-12-23 Yudi Pawitan , Chris Holmes

The $\Lambda$ Cold Dark Matter model ($\Lambda$CDM) represents the current standard model in cosmology. Within this, there is a tension between the value of the Hubble constant, $H_0$, inferred from local distance indicators and the angular…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-26 Edvard Mörtsell , Suhail Dhawan

We present an extensive comparison of models of structure formation with observations, based on linear and quasi-linear theory. We assume a critical matter density, and study both cold dark matter models and cold plus hot dark matter…

Astrophysics · Physics 2015-06-24 Andrew R Liddle , David H Lyth , R K Schaefer , Q Shafi , Pedro T P Viana

Constraints on the properties of the cosmological dark matter have previously been obtained in a model-independent fashion using the Generalised Dark Matter (GDM) framework. Here we extend that work in several directions: We consider the…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-05 Daniel B Thomas , Michael Kopp , Katarina Markovič

The time evolution of the number density of galaxy clusters and their mass and temperature functions are used to constrain cosmological parameters in the spatially flat dark matter models containing a fraction of hot particles (massive…

Astrophysics · Physics 2009-11-07 N. A. Arhipova , T. Kahniashvili , V. N. Lukash

We lay out the framework to numerically study nonlinear structure formation in the context of scalar-field-coupled cold dark matter models (phiCDM models) where the scalar field phi serves as dynamical dark energy. Adopting parameters for…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 HongSheng Zhao , Andrea V. Maccio' , Baojiu Li , Henk Hoekstra , Martin Feix

We review the current state of the theory of large scale structure in a warm dark matter (WDM) cosmological model. In particular, we focus on the non-linear modelling of the matter power spectrum and on the mass function of dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-18 Katarina Markovič , Matteo Viel

When Cold Dark Matter (CDM) power spectrum normalized by COBE results, its amplitude at smaller scales can be parametrized by $\Gamma\sim\Omega_0h$. The expected variations of Hubble flows in two samples, the sample of 36 clusters in the…

Astrophysics · Physics 2016-01-13 Xiangdong Shi

Observational evidence for the presence of a preferred scale around 100 Mpc in the distribution of high-density regions in the Universe is summarised. Toy models with various degrees of regularity are analysed to understand better the…

Astrophysics · Physics 2007-05-23 Jaan Einasto

The current standard model of cosmology, the LambdaCDM model, is based on the homogeneous FLRW solutions of the Einstein equations to which some perturbations are added to account for the CMB features and structure formation at large…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-14 Marie-Noëlle Célérier

If the hot, X-ray emitting gas in rich clusters forms a fair sample of the universe (as in Cold Dark Matter (CDM) models), and the universe is at the critical density, $\Omega_T = 1$, then the data appears to imply a baryon fraction,…

Astrophysics · Physics 2009-10-28 Russell W. Strickland , David N. Schramm

Observations of the cosmic microwave background (CMB) together with weak lensing measurements of the clustering of large scale cosmological structures and local measurements of the Hubble constant pose a challenge to the standard…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-08 Marco Raveri , Wayne Hu , Timothy Hoffman , Lian-Tao Wang

Recently, spatially inhomogeneous cosmological models have been proposed as an alternative to the LCDM model, with the aim of reproducing the late time dynamics of the Universe without introducing a cosmological constant or dark energy.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Peter Dunsby , Naureen Goheer , Bob Osano , Jean-Philippe Uzan

We adopt a bottom-up approach to reconstruct the possible neutrino mass matrix patterns, in the hypothesis that $\lambda = \sin \theta_C$, where $\theta_C$ is the Cabibbo angle, is a useful expansion parameter in the neutrino sector as it…

High Energy Physics - Phenomenology · Physics 2010-09-14 Fu-Sin Ling

A non--minimally coupled quintessence model is investigated and the conditions for a stationary solution to the coincidence problem are obtained. For a conformally coupled scalar field and dissipative matter, a general solution possessing…

Astrophysics · Physics 2009-11-10 Luis P. Chimento , Alejandro S. Jakubi , Diego Pavon