Studying the Large Scale Structure with cosmological voids
This is a full-time semester project carried out during the third semester of my master studies in astrophysics.
- Duration: 5-6 months (February 2022 - July 2022)
- Supervisor: Jean-Paul Kneib, Andrei Variu (LASTRO, EPFL)
Overview
Cosmic voids are large regions of space in the Universe which have low matter densities. These structures are influenced by the expansion of the Universe and the clustering of matter. Thus, they can be used to better understand the cosmology and the large scale structure. The purpose of this project is to test whether numerical models could be used to extract cosmological information from the clustering of voids and to perform an analysis on simulations.
Abstract
In this report, we detail our project that focused on testing whether numerical models could be used to extract cosmological information from the clustering of voids. We present an analysis of the RSD effect using a multipole decomposition of the void- galaxy cross-correlation using a Big MultiDark simulation. We compute numerically the void cross-correlation with galaxies in redshift space and compare it to a theoretical Redshift Space Distortion (RSD) model that we compute by finding its cosmological parameters. The parameters that we compute in this project are the average mass density contrast, the void cross-correlation with galaxies in real space and the velocity dispersion profile of galaxies. We also compute the void density contrast and the average (stacked) galaxy velocity profile projected on the void-galaxy separation vector.
References
- Beyond BAO: improving cosmological constraints from BOSS with measurement of the void-galaxy cross-correlation Nadathur et al. 2019
- An accurate linear model for redshift space distortions in the void-galaxy correlation function Nadathur, Percival 2018
- ZOBOV: a parameter-free void-finding algorithm Neyrinck 2008
About this project
- Cosmology, large scale structures, voids
- Baryon accoustic oscillations, RSD effect
- N-body simulations
- Cross-correlations
Links
- Here’s the link to the report.