2PI effective theory at next-to-leading order using the functional renormalization group
M. E. Carrington (Department of Physics, Brandon University, Brandon, Manitoba R7A 6A9 Canada, Winnipeg Institute for Theoretical Physics, Winnipeg, Manitoba, Canada); S. A. Friesen (Department of Physics, Brandon University, Brandon, Manitoba R7A 6A9 Canada); B. A. Meggison (Department of Physics, Brandon University, Brandon, Manitoba R7A 6A9 Canada, Winnipeg Institute for Theoretical Physics, Winnipeg, Manitoba, Canada, Department of Physics, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada); C. D. Phillips (Department of Physics, Brandon University, Brandon, Manitoba R7A 6A9 Canada); D. Pickering (Department of Mathematics, Brandon University, Brandon, Manitoba R7A 6A9 Canada); et al - Show all 6 authors
We consider a symmetric scalar theory with quartic coupling in four dimensions. We show that the four-loop 2PI calculation can be done using a renormalization group method. The calculation involves one bare coupling constant which is introduced at the level of the Lagrangian and is therefore conceptually simpler than a standard 2PI calculation, which requires multiple counterterms. We explain how our method can be used to do the corresponding calculation at the 4PI level, which cannot be done using any known method by introducing counterterms.
