相关论文: Testing Cold Dark Matter Models At Moderate to Hig…
A recent observation of Steidel et al. indicates that a substantial fraction of giant galaxies were formed at an epoch as early as redshift $z>3-3.5$. We show that this early formation of giant galaxies gives strong constraints on models of…
The thermodynamic and dynamical properties of a variable dark energy model with density scaling as rho_x \propto (1+z)^m, z being the redshift, are discussed following the outline of Jetzer et al. This kind of models are proven to lead to…
The power spectrum of density fluctuations measured from galaxy redshift surveys provides important constraints on models for the formation of large-scale structure. I present new results for a redshift sample of 15,000 galaxies, and review…
We discuss variants of Cold Dark Matter (CDM) dominated cosmological models that give good agreement with a range of observations. We consider models with hot dark matter, tilt, $\Omega < 1$, or a cosmological constant. We also discuss the…
The abundance of the most massive objects in the Universe at different epochs is a very sensitive probe of the cosmic background evolution and of the growth history of density perturbations, and could provide a powerful tool to distinguish…
We investigate the clustering of high redshift galaxies in five variants of the cold dark matter (CDM) scenario, using hydrodynamic cosmological simulations that resolve the formation of systems with circular velocities $v_c \geq 100 \kms$…
We examine high-resolution gravitational N-body simulations of the $\Omega=1$ cold dark matter (CDM) model in order to determine whether there is any normalization of the initial density fluctuation spectrum that yields acceptable results…
The cold dark matter (CDM) model of structure formation, normalized on large scales, leads to excessive pairwise velocity dispersions on small scales. In an attempt to circumvent this problem, we study three scenarios (all with $\Omega=1$)…
We discuss the thermodynamic and dynamical properties of a variable dark energy model with density scaling as $\rho_x \propto (1+z)^{m}$, z being the redshift. These models lead to the creation/disruption of matter and radiation, which…
The epoch of galaxy formation provides an important additional test of cosmological theories. Cold-dark-matter (CDM) models with cosmological constant ($\Lambda$) are designed to account for the observed excess power in galaxy distribution,…
The abundance of galactic systems at high redshifts can impose a strong constraint on the cold+hot dark matter (CDM+HDM) models. The hot component reduces the excessive small-scale power in the COBE-normalized CDM model but also delays the…
With the imminent promise of constraints on the epoch of reionization from observations of microwave background anisotropies, the question of whether or not the standard Cold Dark Matter (CDM) model permits early reionization has been…
Cosmological analysis based on currently available observations are unable to rule out a sizeable coupling among the dark energy and dark matter fluids. We explore a variety of coupled dark matter-dark energy models, which satisfy cosmic…
The nature of dark matter is increasingly constrained by cosmological data. In this paper, we examine the implications of the Cosmic Microwave Background anisotropy limits on the density of cold dark matter under different theoretical…
Cosmological models with a positive cosmological constant and $\Omega_0<1$ have a number of attractive features. A larger Hubble constant, which can be compatible with the recent HST estimate, and a large fraction of baryon density in…
The abundances of groups and clusters of galaxies are expected to have changed substantially since high redshift, with the strength of this evolution dependent upon fundamental cosmological parameters. Upcoming large redshift surveys of…
We present a series of four simulations of Cold Dark Matter (CDM) and Cold + Hot Dark Matter (CHDM) cosmologies. We discuss the power spectrum and correlation functions in real and redshift space, with comparisons to the CfA2 and IRAS…
Here we discuss what are perhaps the two most popular variants of CDM that might agree with the data: \lcdm\ and CHDM. While the predictions of COBE-normalized \lcdm\ and CHDM both agree well with the available data on scales of $\sim 10$…
COBE-normalized flat (matter plus cosmological constant) and open Cold Dark Matter (CDM) models are tested by comparing their expected Hubble flow variations and the observed variations in a Type Ia supernova sample and a Tully Fisher…
The canonical cosmological constant dominated cold dark matter model (LCDM) may possess too much power on small scales at z=0, manifested as central over-concentration of dark matter and over-abundance of dwarf galaxies. We suggest an…