| Title: |
Cosmology with the galaxy bispectrum |
| Authors: |
Yankelevich, Victoria |
| Contributors: |
Porciani, Cristiano; Schneider, Peter |
| Publisher Information: |
Universitäts- und Landesbibliothek Bonn |
| Publication Year: |
2019 |
| Collection: |
bonndoc - The Repository of the University of Bonn |
| Subject Terms: |
ddc:520 |
| Description: |
The last decades witnessed huge progress in understanding the large-scale structure of the Universe. While homogeneous and isotropic on the largest scales, the matter and galaxy distributions display complex patterns on smaller scales where we observe elongated filaments, compact clusters and volume-filling underdense regions. These features are not captured by studies of two-point statistics like the power spectrum that does not retain information on the phases of the Fourier modes of the density field. Therefore, higher-order statistics like the bispectrum should provide additional information. However, the exact gain has never been measured convincingly. Current and forthcoming galaxy redshift surveys, such as $textit{Euclid}$, cover large enough volumes to provide robust measurements of the bispectrum. For this reason, it is a perfect time to develop the tools to interpret these measurements and extract cosmological information out of them. The main goals of this work are to explore this field, to study the properties of the bispectrum, discover and demonstrate advantages and difficulties of making the bispectrum a useful and applicable tool to learn more about the Universe. Historically the bispectrum has been considered a useful tool to learn about the statistical properties of the primordial density perturbations that seeded structure formation, and to study non-linear processes like gravitational dynamics and galaxy biasing. Since these processes generate different functional dependencies on the triangular configurations, they can be disentangled by fitting bispectrum measurements with theoretical templates. This will ultimately remove the degeneracy between the linear bias coefficient and the amplitude of the dark matter perturbations found in power-spectrum studies. However, the potential of the bispectrum as a means to extract additional cosmological information has never been explored. One part of my thesis has been devoted to quantifying this potential using the Fisher-matrix formalism. Firstly, it ... |
| Document Type: |
doctoral or postdoctoral thesis |
| File Description: |
application/pdf |
| Language: |
English |
| Relation: |
info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:5n-56046; https://hdl.handle.net/20.500.11811/8087 |
| Availability: |
https://hdl.handle.net/20.500.11811/8087 |
| Rights: |
In Copyright ; http://rightsstatements.org/vocab/InC/1.0/ ; openAccess |
| Accession Number: |
edsbas.CA6C6B49 |
| Database: |
BASE |