Triangle Seminars
Wednesday, 18 Jan 2006
Sigma models on supermanifolds: Integrability and Conformal Invariance
📍 London
Charles Young
(York)
Thursday, 19 Jan 2006
Matrix Representation of the Combinatorics of Renormalization in Perturbative QFT
Kurusch Ebrahimi-Fard
(IHES)
Abstract:
Kreimer discovered a Hopf algebra structure underlying the
combinatorics of renormalization in perturbative quantum field
theory. Later, Connes and Kreimer explored the link to
non-commutative geometry via a Hopf algebra of rooted trees and
described a Hopf algebra of Feynman graphs. After reviewing these
developments in some detail we show in this talk how to organize
the combinatorics of renormalization in terms of unipotent
triangular matrix representations. A simple decomposition of such
matrices is used to characterize the process of renormalization.
We thereby recover a matrix (anti-)representation of the Birkhoff
decomposition of Connes and Kreimer.
Kreimer discovered a Hopf algebra structure underlying the
combinatorics of renormalization in perturbative quantum field
theory. Later, Connes and Kreimer explored the link to
non-commutative geometry via a Hopf algebra of rooted trees and
described a Hopf algebra of Feynman graphs. After reviewing these
developments in some detail we show in this talk how to organize
the combinatorics of renormalization in terms of unipotent
triangular matrix representations. A simple decomposition of such
matrices is used to characterize the process of renormalization.
We thereby recover a matrix (anti-)representation of the Birkhoff
decomposition of Connes and Kreimer.
Posted by: QMW
Mass Corrections to KK-states in Dipole Field Theories
Karl Landsteiner
(UAM)