Biography

I was an Honours student supervised by Cullan and Tamara at The University of Queensland. My Honours project focused on whether combining the position and velocity measurements of galaxies can reduce the cosmic variance (an effect introduced by the inhomogeneity in the local universe). I finished my Honours project in November 2020 and started my Ph.D. project in July 2021 (expected to finish in January 2025). My first project focuses on using the motion of galaxies (peculiar velocities) to constrain the growth rate of structure of the universe. One of the biggest mysteries of our universe is the nature of dark matter. The two most popular theories are modified theories of gravity and WIMP (Weakly Interacting Massive Particles). Constraining the growth rate of structure helps us determine the strength of gravity. By knowing the strength of gravity, we can determine the correct model of gravity and narrow down the possible candidates for dark matter. In my first project, I combined both the wide-angle effect and the RSD (Redshift Space Distortion) effect for the first time and applied this new model to the largest peculiar velocity catalogue (SDSS peculiar velocity catalogue) at the time. In this paper, we show the constraints are consistent with the predictions from GR (General Relativity). For my second project, I worked on using the analytical covariance matrix and data compression to speed up future cosmological analysis. In this paper, we show that we can compute the analytical covariance matrix around a day while the traditional approach with simulations will take several months. Furthermore, the constraints of cosmological parameters from the analytical covariance matrix are consistent with the ones with the simulated covariance matrix. Lastly, we show with data compression, the speed of MCMC is improved by a factor of four. Therefore, we can obtain constraints of cosmological parameters faster for future surveys. In my third project, I worked on developing a pipeline to fit the DESI power spectrum with PyBird. The results will be released on the 11th of April on the Arxiv. In my last project, I will try to use the pipeline I developed during my first project and apply it to the DESI Y1 peculiar velocity catalogue. It is expected to contain more peculiar velocity measurements than the SDSS peculiar velocity catalogue. Therefore, DESI Y1 peculiar velocity catalogue will help to provide one of the tightest constraints of the growth rate of structure to date and further narrow down the possible candidates for dark matter.

Research interests: Peculiar velocity, dark matter, galaxy power spectrum, data compression, covariance matrix.