Speaker
Prof.
Margaret Carrington
(Brandon University)
Description
The n-particle irreducible effective action is a powerful approach to study non-perturbative systems. The method provides a systematic expansion for which the truncation occurs at the level of the action. At the 2PI level one can renormalize using a complicated procedure which involves introducing multiple sets of counterterms, but the method cannot be extended to higher orders. We have developed a method based on a renormalization group approach which allows us to construct a renormalized theory at any order in the nPI approximation. We present results from a calculation using a scalar theory with quartic coupling in 4 dimensions, at the 4 loop level. Both the 2PI and 4PI theories can be renormalized using one bare coupling constant and one bare mass, which are introduced at the level of the Lagrangian.
Primary author
Prof.
Margaret Carrington
(Brandon University)
