case western reserve university



Cosmic Voids: a useful tool to constrain galaxy formation models and cosmology

Santiago Patiri (CWRU Astronomy)

Cosmic voids are one of the most striking features of the large-scale structure that have not attracted much attention up to now. By means of a careful definition, they can provide very useful information about cosmology and galaxy formation. In this talk, I will present some important results obtained from the study of Cosmic Voids as part of my PhD Thesis. In the first part of the talk, I will discuss the dependence of the physical properties of galaxies with the environment. Using the Sloan Digital Sky Survey, we extensively studied the properties of the galaxies lying in large Cosmic Voids. I will show that these properties are essentially the same as those of the field galaxies. In fact, for a fixed luminosity, there are no systematic differences in color, morphology and even specific star formation rates.

In the second part of the talk, I will present first results on constraints of the value of the normalization of the linear power spectrum of mass fluctuations (\sigma_8) using the statistics of voids found in the 2dFGRS. I will show that this void statistics is a very good tool to constrain this parameter with good precision.