Tracing the Cosmic Web, Leiden, the Netherlands

Abstract:

The cosmic web of large scale structure forms through the gravitational collapse of an initially flat 6-D phase-space manifold. ORIGAMI identifies halos, filaments, walls, and voids in simulations by finding the folds in phase-space: the morphology of each particle is determined by the number of orthogonal axes along which it has undergone shell-crossing, giving a dynamical, parameter-free definition of structures and their boundaries. I will describe the ORIGAMI method, present the cosmic web classification results for the workshop data, and discuss some interesting features of halos and voids defined by shell-crossing instead of over- or under-density.