相关论文: Large--Scale Angular Correlations in CDM Models

Many different techniques to analyze galaxy clustering data and obtain cosmological constraints have been proposed, tested and used. Given the large amount of data that will be available soon, it is worth investigating new observables and…

It has been argued recently by Copi etal (2009) that the lack of large angular correlations of the CMB temperature field provides strong evidence against the standard, statistically isotropic, inflationary LambdaCDM cosmology. We compare…

The two point angular correlation function is an excellent measure of structure in the universe. To extract from it the three dimensional power spectrum, one must invert Limber's Equation. Here we perform this inversion using a Bayesian…

We evaluate the dependence of the cluster correlation length r_c on the mean intercluster separation D_c, for three models with critical matter density, vanishing vacuum energy (Lambda = 0) and COBE normalized: a tilted CDM (tCDM) model…

We perform a discrete wavelet analysis of the COBE-DMR 4yr sky maps and find a significant scale-scale correlation on angular scales from about 11 to 22 degrees, only in the DMR face centered on the North Galactic Pole. This non-Gaussian…

The emergence of several unexpected large-scale features in the cosmic microwave background (CMB) has pointed to possible new physics driving the origin of density fluctuations in the early Universe and their evolution into the large-scale…

Using cosmological simulations, we make predictions for the distribution of clusters in a plausible non-gaussian model where primordial voids nucleated during inflation act together with scale-invariant adiabatic gaussian fluctuations as…

We study the angular correlations of various galaxy catalogs (CfA1, SSRS1, Perseus-Pisces, APM Bright Galaxies and Zwicky). We find that the angular correlation exponent is $\gamma_a= 0.1 \pm 0.1$ rather than $\gamma_a=0.7$ as usually found…

We use very large cosmological N--body simulations to obtain accurate predictions for the two-point correlations and power spectra of mass-limited samples of galaxy clusters. We consider two currently popular cold dark matter (CDM)…

We produce mock angular catalogues from simulations with different initial power spectra to test methods that recover measures of clustering in three dimensions, such as the power spectrum, variance and higher order cumulants. We find that…

We cross-correlate APM and SDSS galaxies with background QSOs from the 2dF QSO Redshift Survey, and detect a significant (2.8sigma) anti-correlation. The lack of a signal between 2dF stars and our galaxy samples suggests the…

We show that if a sample of galaxy clusters is complete above some mass threshold, then hierarchical clustering theories for structure formation predict its autocorrelation function to be determined purely by the cluster abundance and by…

A lack of correlations in the microwave background temperature between sky directions separated by angles larger than 60 degrees has recently been confirmed by data from the Planck satellite. This feature arises as a random occurrence…

Several unexpected features are observed at large angular scales in the CMB temperature anisotropy measurements by both WMAP and Planck. These include the lack of both variance and correlation, alignment of the lowest multipole moments with…

The lack of large-angle correlations in the fluctuations of the cosmic microwave background (CMB) conflicts with predictions of slow-roll inflation. But though probabilities (< 0.24%) for the missing correlations disfavor the conventional…

We calculated spatial correlation functions of galaxies, $\xi(r)$, structure functions, $g(r)=1 +\xi(r)$, gradient functions, $\gamma(r)= d \log g(r)/ d \log r$, and fractal dimension functions, $D(r)= 3+\gamma(r)$, using dark matter…

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…

A new analysis is presented of the angular correlation function $C(\Theta)$ of cosmic microwave background (CMB) temperature at large angular separation, based on published maps derived from {\sl WMAP} and {\sl Planck} satellite data, using…

We consider the hypothesis that nonlocal, omnidirectional, causally-coherent quantum entanglement of inflationary horizons may account for some well-known measured anomalies of Cosmic Microwave Background (CMB) anisotropy on large angular…

We characterize galaxy correlations in the Sloan Digital Sky Survey by measuring several moments of galaxy counts in spheres. We firstly find that the average counts grows as a power-law function of the distance with an exponent D= 2.1+-…