UBC Mathematics Department
http://www.math.ubc.ca
Feynman diagrams are a tool used for identifying the dominant behaviour of various complicated physical systems. First I will explain the rules for building and computing Feynman diagrams for many electron systems. Then I will focus on a particular class of such diagrams (Fermion loops). The numerical evaluation of Fermion loops for two-dimensional systems suggested some surprising results. These are proven rigorously, using methods of complex algebraic geometry.