My research focuses on astroparticle and early universe physics. What is astroparticle physics? It is an offshoot of particle physics that seeks to study elementary particles and interactions in the context of astrophysics and cosmology. This can include probing such fundamental questions as: What is dark matter? What is the origin of the highest energy cosmic rays? What are the properties of neutrinos and what do they tell us about the universe? What is the nature of gravity? Experiments ranging from underground laboratories, specially designed telescopes and detector arrays, to even satellite experiments observe a wide range of cosmic particles including neutrinos, gamma-rays and cosmic rays at the highest energies. I am primarily a theorist who is interested in interpreting the data provided by these experiments to answer specifically the following questions: are microwave and gamma-ray observations giving us the signature of dark matter? Do observations of the highest energy cosmic rays and photons hint at new fundamental physics that can help us determine the nature of gravity? -and- Where do these particles come from in the first place? Select a specific topic that I research below: