Karen Yeats, Simon Fraser University
"Tree Feynman rules”
Tree Feynman rules are maps from the Connes-Kreimer Hopf algebra of rooted trees to a polynomial ring which satisfy certain algebraic properties. It’s not too hard to show what the most general possible tree Feynman rules are; the answer is rather combinatorial. I’ll explain the background and how this argument goes. (This will ultimately be a small part of a larger joint work with Dirk Kreimer and Spencer Bloch.)