PERMUTATIONS AND IRREDUCIBLE FEYNMAN DIAGRAMS

GAP Seminar

Meeting Details

For more information about this meeting, contact Ping Xu, Nigel Higson, Mathieu Stiénon.

Speaker: Adrian Ocneanu, Penn State

Abstract: We describe a new internal structure of a permutation, a canonical forest structure, in which the nodes of trees consist of a special class of permutations, which we called primitive. Primitive permutations are encoding naturally a basic structure in perturbative Quantum Field Theory, the irreducible (2-connected) fermionic line Feynman diagrams, for which no combinatorial construction existed before. An algorithm shows that such Feynman diagrams live naturally on the graph of the permutation. The algorithms provide new constructions and generating functions for a family unifying the treatment of derangements and Eulerian


Room Reservation Information

Room Number: 106 McAllister

Date: 10/22/2013

Time: 2:30pm - 3:30pm