The development of quantum field theory and, half a century later, of string theory was motivated by the desire to reconcile the laws of quantum physics with Einstein’s theory of special and general relativity.

Our current understanding of the basic constituents of matter and interactions among them is based on quantum field theory and gauge symmetries.

Our current understanding of the basic constituents of matter and interactions among them is based on quantum field theory and gauge symmetries. All known forces in Nature are mediated by gauge fields.