Speaker
Dr
Matthias Puhr
(University of Regensburg)
Description
In general, perturbative expansions of observables in quantum field
theories are divergent (asymptotic) series. It is often possible to
apply resummation techniques to assign a unique finite value to the
asymptotic series, but a particular pattern of divergence, the
so-called renormalon, gives rise to non-perturbative ambiguities. The
framework of numerical stochastic perturbation theory (NSPT), based on
stochastic quantisation and the Langevin equation, allows us to
compute the coefficients of perturbative expansions up to very high
orders (>40) on the lattice. In this talk we present first results for an
NSPT study of asymptotically free sigma models and discuss possible
renormalon signatures in the expansion of the energy density.
Primary authors
Dr
Falk Bruckmann
(University of Regensburg)
Dr
Matthias Puhr
(University of Regensburg)