Large-scale filamentary structure of the Universe
Using large-scale structure as a probe of cosmology and structure formation has become increasingly popular with the current and upcoming large deep surveys. Guided by numerical simulations and theoretical prediction, analysis of large-scale structure in observations provides complementary information and crosschecks of cosmological parameters from other probes. These analysis also help us to achieve a deeper understanding of structure formation and even the process of galaxy formation. In Chapter 2, I present a weak lensing detection of filamentary structures in the cosmic web, combining data from the Kilo-Degree Survey, the Red Cluster Sequence Lensing Survey and the Canada-France-Hawaii Telescope Lensing Survey. This work has been accepted by Astronomy & Astrophysics as Xia et al. (2020b). In Chapter 3, I describe cosmological analysis using SDSS cluster catalogue and DES Y1 cluster catalogue to constrain f(R) gravity. Our analysis reveals a degeneracy between richness-mass relation and the f(R) halo mass function, and I provide a forecast for constraining f(R) gravity using cluster catalogue from future survey such as the Legacy Survey of Space and Time (LSST). In Chapter 4, I present the first report of spinning filaments measured in the Millennium dark matter cosmological simulations. This work has been published by Monthly Notices of the Royal Astronomical Society as Xia et al. (2020a).