My research has focused primarily on quantum field theory and particle physics phenomenology. My goal is to address some of the fundamental questions of particle physics: What is the source of electroweak symmetry breaking? Why are there different flavors of quarks and leptons? Why do they have different masses? To answer these questions I have worked on supersymmetry, particle cosmology, and precision electroweak tests of the standard model.
My earlier research emphasized studying the effects of non-standard-model physics on precision electroweak measurements. These measurements are important for constraining and ruling out a variety of models that purport to be more fundamental than the standard model of particle physics. This work has often involved building effective field theories to describe the most important degrees of freedom at a particular energy, and relating the properties of such theories to the underlying dynamics.