Abstract
ABSTRACT Using a set of Lambda cold dark matter simulations of cosmic structure formation, we study the evolving connectivity and changing topological structure of the cosmic web using state-of-the-art tools of multiscale topological data analysis (TDA). We follow the development of the cosmic web topology in terms of the evolution of Betti number curves and feature persistence diagrams of the three (topological) classes of structural features: matter concentrations, filaments and tunnels, and voids. The Betti curves specify the prominence of features as a function of density level, and their evolution with cosmic epoch reflects the changing network connections between these structural features. The persistence diagrams quantify the longevity and stability of topological features. In this study, we establish, for the first time, the link between persistence diagrams, the features they show, and the gravitationally driven cosmic structure formation process. By following the diagrams’ development over cosmic time, the link between the multiscale topology of the cosmic web and the hierarchical buildup of cosmic structure is established. The sharp apexes in the diagrams are intimately related to key transitions in the structure formation process. The apex in the matter concentration diagrams coincides with the density level at which, typically, they detach from the Hubble expansion and begin to collapse. At that level many individual islands merge to form the network of the cosmic web and a large number of filaments and tunnels emerge to establish its connecting bridges. The location trends of the apex possess a self-similar character that can be related to the cosmic web’s hierarchical buildup. We find that persistence diagrams provide a significantly higher and more profound level of information on the structure formation process than more global summary statistics like Euler characteristic or Betti numbers.
Highlights
In this study, we analyse the topological structure and connectivity of the cosmic web (Bond, Kofman & Pogosyan 1996; van de Weygaert & Bond 2008) in terms of the multiscale topological formalism of persistence and Betti numbers
The principal intentions of this study are (1) to assess and quantify the connectivity of the cosmic web in terms of the levels at which its various structural components get joined into the overall web-like network, (2) establish the relationship between the characteristics of the Betti number curves and persistence diagrams and the gravitationally driven cosmic structure formation process, (3) to explore the sensitivity of the structure and topology of the cosmic web to the underlying cosmology, and (4) to assess the extent to which the topological measures are able to extract cosmological information
Following the work laid out in van de Weygaert et al (2011), Nevenzeel (2013), Pranav et al (2017, 2019a, b), and Feldbrugge et al (2019) in this study, we extend the topological analysis of the cosmic web to the analysis of the redshift evolution of structure on simulations within the Lambda cold dark matter ( CDM) cosmology
Summary
We analyse the topological structure and connectivity of the cosmic web (Bond, Kofman & Pogosyan 1996; van de Weygaert & Bond 2008) in terms of the multiscale topological formalism of persistence and Betti numbers. The principal intentions of this study are (1) to assess and quantify the connectivity of the cosmic web in terms of the levels at which its various structural components get joined into the overall web-like network, (2) establish the relationship between the characteristics of the Betti number curves and persistence diagrams and the gravitationally driven cosmic structure formation process, (3) to explore the sensitivity of the structure and topology of the cosmic web to the underlying cosmology, and (4) to assess the extent to which the topological measures are able to extract cosmological information This concerns aspects such as the nature of dark matter, dark energy, possible deviations from standard gravity, and/or nonGaussian initial conditions. We will apply this probe to observational data, with the aim of differentiating between models and providing constraints on the nature of dark matter, dark energy and other global cosmologically relevant factors
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.