The Cosmic Web: Structural Complexity and Dynamics of the Megaparsec Universe

by Rien van de Weijgaert (Kapteyn Institute, University of Groningen)

Tuesday 23 Jan 2018, 13:15 → 14:15 Europe/Stockholm

FB42

The Cosmic Web is the fundamental spatial organization of matter in the Universe on scales of a few up to a hundred Megaparsec, scales at which the Universe still resides in a state of moderate dynamical evolution. Galaxies, intergalactic gas and dark matter exist in a wispy weblike spatial arrangement consisting of dense compact clusters, elongated filaments, and sheetlike walls, amidst large near-empty void regions. The weblike pattern is marked by prominent anisotropic features, a distinct multiscale character, a complex spatial connectivity of its various morphological components and a clear asymmetry between voids and overdense regions. This seminar will describe the structure and evolution of physical and population properties of the structural components of the Cosmic Web. The analysis is based on our Nexus/MMF Multiscale Morphology formalism, an explicit geometric and multi-scale -- parameter-free and scale-free -- method to identify morphological features in the Cosmic Web. This results in a systematic study of the evolving size and volume distribution of these structural components. Subsequently, we assess the mass and halo distribution in the filaments and walls, and follow their evolution. To study the dynamical evolution of the cosmic web, we describe our adhesion model of cosmic structure formation based on Voronoi and Delaunay tessellations. Subsequently, we will shortly describe how a full phase-space analysis allows us to understand the growth of structural complexity in terms of the emergence and spatial connectivity of singularities and caustics. (Host: Evan)