Karen Yeats

I will give an overview of a few places where combinatorial structures have an interesting role to play in quantum field theory and which I have been involved in to varying degrees, from the Connes-Kreimer Hopf algebra and other renormalization Hopf...

Primitive Feynman graphs in Phi^4 theory give rise to transcendental numbers which, from the work of people like David Broadhurst, are multiple zeta values in known examples. Very little is known in general. Even how to predict the weight of the zeta...

Last year Francis Brown and Oliver Schnetz defined the c_2 invariant of a graph. Let p be prime, take the Kirchhoff polynomial of a graph, and count points on the variety of this polynomial over the finite field with p elements. For the graphs of...

Dyson-Schwinger equations are certain integral equations in quantum field theory which mirror the combinatorial decompositions of trees by subtrees, or of graphs by subgraphs. At the analytic level, many cases can still be interpreted combinatorially...

The $c_2$ invariant is an arithmetic graph invariant introduced by Brown and Schnetz in order to better understand Feynman integrals. I will look at what can be said about the $c_2$ invariant of 4-regular circulant graphs with one vertex removed. The...

I will give an overview of a few places where combinatorial structures have an interesting role to play in quantum field theory and which I have been involved in to varying degrees, from the Connes-Kreimer Hopf algebra and other renormalization Hopf...