Wednesday Colloquium


"The bright and dark side of cosmic voids"

Krzysztof Bolejko (School of Physics, The University of Sydney)

More than half of the volume of our Universe is occupied by cosmic voids. Cosmic voids are regions where matter density is much below the mean density of the Universe. In galaxy surveys they appear as vast empty spaces between filaments, which contain very few or no galaxies. Cosmic voids are not merely regions of galaxy avoidance they also affect optical properties of the Universe. During the talk I will discuss how imagines of background objects are distorted when observed through cosmic voids. I will show how these distortions can help us to understand various phenomena and how we can use them to learn more about dynamics of cosmic voids and global properties of our Universe.