Colloquium, Thursday, September 23, 4 pm:


FEYNMAN DIAGRAMS

Pavel Etingof, Massachusetts Institute of Technology



Abstract: Feynman diagrams are a combinatorial formalism which play a vital role in quantum field theory. They stem from the attempt to write explicitly the stationary phase asymptotic expansion of rapidly oscillating integrals. While the existence of this expansion is well known to many mathematicians, the explicit formula for it, while being basic to every quantum physicist, is much less widely known in the mathematical community and can rarely be found in mathematical texts. Nevertheless it is completely elementary and also very useful. I will explain what this formula is, what it has to do with physics, and how it can be used in mathematics.

Prerequisites: Calculus 3, linear algebra with tensors.