Tessellating the cosmological dark-matter sheet: origami creases in the universe and ways to find them

TL;DR

This paper introduces a novel approach to analyzing the large-scale structure of the universe by modeling the dark matter distribution as a tessellated sheet that folds like origami, revealing caustics and stream regions.

Contribution

It presents a new coordinate-based tessellation method for the dark matter sheet, enhancing analysis of cosmic web structures and simulation data.

Findings

Identification of caustics as origami-like folds in dark matter

Improved density measurement techniques using tessellations

Method for detecting overlapping stream regions

Abstract

Tessellations are valuable both conceptually and for analysis in the study of the large-scale structure of the universe. They provide a conceptual model for the 'cosmic web,' and are of great use to analyze cosmological data. Here we describe tessellations in another set of coordinates, of the initially flat sheet of dark matter that gravity folds up in rough analogy to origami. The folds that develop are called caustics, and they tessellate space into stream regions. Tessellations of the dark-matter sheet are also useful in simulation analysis, for instance for density measurement, and to identify structures where streams overlap.