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相关论文: On the Universality of the Bound-Zone Peculiar Vel…

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We numerically study the effects of constrained interacting dark energy (CIDER) on the bound-zone velocity profiles around massive dark matter halos. Analyzing the CIDER simulations performed by Baldi (2023) for three different cases of…

宇宙学与河外天体物理 · 物理学 2024-09-19 Jounghun Lee , Marco Baldi

We present a unified analysis of the linear evolution of peculiar-velocity perturbations in the distribution of pressureless matter after recombination. Our study is carried out within the framework of full general relativity and…

广义相对论与量子宇宙学 · 物理学 2026-04-29 Evanthia Patliaka , Christos G. Tsagas

The evolution of marginally bound supercluster-like objects in an accelerating LambdaCDM Universe is followed, by means of cosmological simulations, from the present time to an expansion factor a = 100. The objects are identified on the…

Peculiar velocities are an important probe of the growth rate of mass density fluctuations in the Universe. Most previous studies have focussed exclusively on measuring peculiar velocities at intermediate ($0.2 < z < 1$) redshifts using…

宇宙学与河外天体物理 · 物理学 2015-06-04 Michael J. Hudson , Stephen J. Turnbull

We study the distribution functions of mass and circular velocity for dark matter halos in N-body simulations of the $\Lambda$CDM cosmology, addressing redshift and environmental dependence. The dynamical range enables us to resolve…

Although the spin parameter of dark matter halos is well known to follow a log-normal distribution at fixed epoch, its quantitative redshift evolution - encompassing both the mean and the dispersion - remains only partially explored. Prior…

宇宙学与河外天体物理 · 物理学 2026-04-27 Tomas Riera , Alexander Knebe , Chris Power , Robert Adriel Mostoghiu Paun , Adam Ussing

Large-scale bulk peculiar motions introduce a characteristic length scale, inside which the local kinematics are dominated by peculiar-velocity perturbations rather than by the background Hubble expansion. Regions smaller than the…

广义相对论与量子宇宙学 · 物理学 2022-06-29 Christos G. Tsagas

Galaxy cluster peculiar velocities can be inferred from high-sensitivity, high-resolution multiple-frequency observations in the 30 to 400 GHz range. While galaxy cluster counts and power spectra are sensitive to the growth factor, peculiar…

天体物理学 · 物理学 2009-11-07 A. Peel , L. Knox

We revisit the epoch of cosmic speed-up characterized by the redshift of transition from a decelerated to an accelerated phase. This redshift is termed the transition redshift ($z_t$). We use the spatially Flat and Non-Flat variants of the…

宇宙学与河外天体物理 · 物理学 2023-08-02 David Dahiya , Deepak Jain

The expansion rate of the Universe changes with time, initially slowing (decelerating) when the universe was matter dominated, because of the mutual gravitational attraction of all the matter in it, and more recently speeding up…

宇宙学与河外天体物理 · 物理学 2013-09-17 Muhammad Omer Farooq

We give a summary of our recent studies of spatial and velocity biases of galaxy-size halos in cosmological models. Recent progress in numerical techniques made it possible to simulate halos in large volumes with a such accuracy that halos…

天体物理学 · 物理学 2007-05-23 Anatoly Klypin , Andrey V. Kravtsov , Pedro Colin

Peculiar velocity surveys, which measure galaxy peculiar velocities directly from standard candles in addition to redshifts, can provide strong constraints on the linear growth rate of cosmological large-scale structure at low redshift. The…

The existence of 'peculiar' velocities due to the formation of cosmic structure marks a point of discord between the real Universe and the usually assumed Friedmann-Lema\'{i}tre-Robertson-Walker metric which accomodates only the smooth…

宇宙学与河外天体物理 · 物理学 2024-05-09 Roya Mohayaee , Mohamed Rameez , Subir Sarkar

The evolution of the spin parameter of dark halos and the dependence on the halo merging history in a set of dissipationless cosmological LCDM simulations is investigated. Special focus is placed on the differences of the two commonly used…

天体物理学 · 物理学 2009-11-11 Helmut Hetznecker , Andreas Burkert

We extend the earlier linear studies of cosmological peculiar velocities to Friedmann universes with nonzero spatial curvature. In the process, we also compare our results with those obtained in cosmologies with Euclidean spatial sections.…

广义相对论与量子宇宙学 · 物理学 2024-08-28 Eleftheria P. Miliou , Christos G. Tsagas

Peculiar motion introduces systematic variations in the observed luminosity distribution of galaxies. This allows one to constrain the cosmic peculiar velocity field from large galaxy redshift surveys. Using around half a million galaxies…

宇宙学与河外天体物理 · 物理学 2016-10-19 Martin Feix , Adi Nusser , Enzo Branchini

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

Knowing the late time evolution of the Universe and finding out the causes for this evolution are the important challenges of modern cosmology. In this work, we adopt a model-independent cosmographic approach and approximate the Hubble…

宇宙学与河外天体物理 · 物理学 2019-01-23 Salvatore Capozziello , Ruchika , Anjan A Sen

We give a summary of recent results on spatial and velocity biases in cosmological models. Progress in numerical techniques made it possible to simulate halos in large volumes with a such accuracy that halos survive in dense environments of…

天体物理学 · 物理学 2007-05-23 Anatoly Klypin

We explore the observational adequacy of a class of Unified Dark Energy/Matter (UDE/M) models with a fast transition. Our constraints are set using a combination of geometric probes, some low redshift ones, and some high redshift ones (CMB…

宇宙学与河外天体物理 · 物理学 2016-03-02 Ruth Lazkoz , Iker Leanizbarrutia , Vincenzo Salzano
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