Browsing by Author "Chan, Victor Carl"

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    Wrestling with Cosmic Scales
    (2024-06) Chan, Victor Carl; Hložek, Renée; Bovy, Jo; Astronomy and Astrophysics
    The $\Lambda$CDM model of cosmology has had resounding success in describing the evolution of the Universe as a whole throughout cosmic history. This has been corroborated by a wide variety of experiments and observations across all cosmic scales, and we have entered an era of precision experiments that allow us to scrutinize the model's predictions at smaller scales than ever. This thesis presents a collection of studies on the impact of existing and upcoming observational data on constraints of extensions to the standard cosmological model through thorough analyses of experiment systematics, and the development of new methodology. We begin with a study of the Gaia mission's parallax zero point, and we show that Gaia data can independently secure uncertainties of geometric anchors in future determinations of the local distance ladder. This will be useful for verifying or disputing tensions between early- and late-time estimates of the Hubble constant, which describes the present rate of the Universe's expansion. We continue with a study of the impact of detector crosstalk systematics on upcoming searches for primordial gravitational wave signatures in the cosmic microwave background, which require unprecedented levels of sensitivity and precision. The results of our work directly inform the development and design of future experiments. We then present the development of the Small Correlated Against Large Estimator for directly quantifying the small-scale statistics of gravitational lensing in the cosmic microwave background without the need for traditional reconstruction of the lensing deflection field. Our method can be used to improve our understanding of dark matter and matter clustering at the scales of galaxy clusters, and it can help to provide a detection of the minimum neutrino mass in upcoming cosmic microwave background experiments.