I was an American theoretical physicist, known for my work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, the physics of the superfluidity of supercooled liquid helium, as well as my work in particle physics for which he proposed the parton model. For contributions to the development of quantum electrodynamics, I received the Nobel Prize in Physics in 1965 jointly with Julian Schwinger and Shin'ichirō Tomonaga.