| dc.description.abstract | The accelerating expansion of our universe is currently theorized to be driven by dark energy, of which the nature is yet a mystery. In this thesis, we investigate the possibility of fluctuations in dark energy and resulting spatial correlations. These fluctuations carry through into the Hubble parameter, affecting cosmological observables. We show that time delays of strong gravitational lenses are dressed by this effect, and correlators of said time delays acquire an angular dependence. To investigate this angular dependence, we construct the angular power spectrum of time delay correlators. Subsequently, we hone in on a specific realization of a fluctuating dark energy density, considering quantum fluctuations of a light scalar field in the early universe and their subsequent imprinted spatial correlations today. We then perform a forecast using a mock dataset for the upcoming Legacy Survey of Space and Time (LSST), comparing the effect to correlations of weak gravitational lenses in regular Lambda CDM. | |
