The Hopf Algebra of Rooted Trees in Epstein-Glaser Renormalization
- Cite this article as:
- Bergbauer, C. & Kreimer, D. Ann. Henri Poincaré (2005) 6: 343. doi:10.1007/s00023-005-0210-3
We show how the Hopf algebra of rooted trees encodes the combinatorics of Epstein-Glaser renormalization and coordinate space renormalization in general. In particular, we prove that the Epstein-Glaser time-ordered products can be obtained from the Hopf algebra by suitable Feynman rules, mapping trees to operator-valued distributions. Twisting the antipode with a renormalization map formally solves the Epstein-Glaser recursion and provides local counterterms due to the Hochschild 1-closedness of the grafting operator B+.