Related papers: Small Deviations from Gaussianity and The Galaxy C…
We consider the conditional galaxy density around each galaxy, and study its fluctuations in the newest samples of the Sloan Digital Sky Survey Data Release 7. Over a large range of scales, both the average conditional density and its…
We analysed the richness--mass scaling of 23 very massive clusters at $0.15<z<0.55$ with homogenously measured weak-lensing masses and richnesses within a fixed aperture of $0.5$ Mpc radius. We found that the richness--mass scaling is very…
We study the role of finiteness and fluctuations about average quantities for basic structural properties of growing networks. We first determine the exact degree distribution of finite networks by generating function approaches. The…
We consider a sample of about 50 distant galaxy clusters at z>0.15 (<z> about 0.3), each cluster having at least 10 galaxies with available redshift in the literature. We select member galaxies, analyze the velocity dispersion profiles, and…
We investigate the phenomenon of clustering of galaxies in an expanding universe by applying the fluctuation theory. We evaluate the fluctuation moments for the number of particles and the correlated fluctuations for number and energy of…
We argue that there has been substantial evolution in the ellipticity of rich galaxy clusters between 0 < z < 0.1, and suggest that this is additional evidence for a low matter-density Universe.
The cluster and field luminosity functions (LFs) determined on large homogeneous samples (N>2200 galaxies each) are almost indistinguishable, down to M^*+4 in the r and i filters, hence suggesting that the effect of the cluster environment…
Evolution of the cluster population has been recognized as a powerful cosmological tool. While the present--day abundance of X-ray clusters is degenerate in $\sigma_8$, $n$ and $\Omega_0$, Oukbir and Blanchard (1992, 1997) have pointed out…
We present the clustering of galaxy clusters as a useful addition to the common set of cosmological observables. The clustering of clusters probes the large-scale structure of the Universe, extending galaxy clustering analysis to the…
We find clusters and superclusters of galaxies using the Data Release 1 of the Sloan Digital Sky Survey. We determine the luminosity function of clusters and find that clusters in a high-density environment have a luminosity a factor of ~5…
In this paper we address the issue of the origin of some observational properties of the galactic globular cluster system. After a preliminary study of some general properties of the main evolutionary processes, we investigate the evolution…
We calculate the kurtosis of a large-scale density field which has undergone weakly non-linear gravitational evolution from arbitrary non-Gaussian initial conditions. It is well known that the weakly evolved {\twelveit skewness} is equal to…
Strong cluster eccentricity evolution for $z \le 0.13$ has appeared in a variety of observational data sets. We examine the evolution of eccentricity in simulated galaxy clusters using a variety of simulation methodologies, amplitude…
Condensation of fluctuations is an interesting phenomenon conceptually distinct from condensation on average. One stricking feature is that, contrary to what happens on average, condensation of fluctuations may occurr even in the absence of…
We present a study of galaxy sizes in the local Universe as a function of galaxy environment, comparing clusters and the general field. Galaxies with radii and masses comparable to high-z massive and compact galaxies represent 4.4% of all…
How multicellular life forms evolved out from unicellular ones constitutes a major problem in our understanding of the evolution of our biosphere. A recent set of experiments involving yeast cell populations has shown that selection for…
Globular clusters were thought to be simple stellar populations, but recent photometric and spectroscopic evidence suggests that the clusters' early formation history was more complicated. In particular, clusters show star-to-star abundance…
We present the ellipticity distribution and its evolution for early-type galaxies in clusters from z~0.8 to z~0, based on the WIde-field Nearby Galaxy-cluster Survey (WINGS)(0.04<z<0.07), and the ESO Distant Cluster Survey…
Early-type dwarf galaxies are found to have high specific globular cluster frequencies which are similar to the high S values that are observed in luminous galaxies of types E and S0. It appears unlikely that cluster formation during…
The properties of the galaxy distribution at large scales are usually studied using statistics which are assumed to be self-averaging inside a given sample. We present a new analysis able to quantitatively map galaxy large scale structures…