2:00–3:00 pm ERC 401
Fei Xu "Peeking Into the Future of Dark Matter Searches"
Non-baryonic dark matter is believed to constitute approximately 27% of the universe's total energy density. Despite its substantial contribution to the cosmic energy budget, its negligible non-gravitational interactions make it extremely challenging to detect. This thesis presentation focuses on potential signals of dark matter in both the electromagnetic spectrum, in particular gamma rays, and in the form of gravitational waves. We focus on predicting the potential observational signals of dark matter, including its particle annihilation in dwarf galaxies, and in the effects of gravitational lensing. More specifically, we evaluate the sensitivity of the proposed Advanced Particle-astrophysics Telescope (APT) to dark matter in dwarf galaxies, finding that such an instrument would be capable of constraining thermal relics with masses as large as mX ~ 600 GeV. Moreover, if the Galactic Center gamma-ray excess is generated by dark matter annihilation, we predict that APT would detect several dwarf galaxies with high significance. Such observations could be used to test the predicted proportionality between the gamma-ray fluxes and J-factors of individual dwarf galaxies, shedding light on the origin of the Galactic Center Excess. In addition to studying gamma rays from dwarf galaxies, we propose a novel method using strong gravitational lensing of gravitational wave sources to probe the gravitational effects of dark matter. In particular, we show that the strong lensing event rate and the time delay distribution of multiply-imaged gravitational-wave binary coalescence events can be used to constrain the mass distribution of the dark matter halo lenses by measuring the characteristic velocity dispersion, sigma*, of the massive elliptical galaxy. With 3rd-generation detectors, we expect to detect ∼50 lensing pairs per year, and constrain sigma* to ∼21% after 5 years using the time delay distribution.
