Speaker
Mr
Daniel Körner
(FSU Jena)
Description
We study the non-perturbative renormalization group flow of the
nonlinear O(N) sigma model in two and three space-time dimensions
using a scheme that combines an effective local Hybrid Monte Carlo
update routine, blockspin transformations and a Monte Carlo demon
method. In two dimensions our results verify perturbative
renormalizability. In three dimensions, we determine the flow
diagram of the theory for various N and different truncations
and find a non-trivial fixed point, which indicates non-perturbative
renormalizability. It is related to the well-studied phase transition
of the O(N) universality class and characterizes the continuum
physics of the model. We compare the obtained renormalization group
flows with recent investigations by means of the Functional
Renormalization Group.
