1201.5710 (Y. Meurice et al.)

Comparison of Improved Perturbative Methods    [PDF]

Y. Meurice, Haiyuan Zou

In many cases of interest, the perturbative series based on conventional
Feynman diagrams have a zero radius of convergence. Series with a finite radius
of convergence can be obtained by either introducing a large field cutoff or by
replacing the exponential of the perturbation by a sequence of approximants as
recently proposed by Pollet, Prokof'ev, and Svistunov. We compare these two
methods for integrals and quantum mechanical problems. The two methods perform
well in complementary regime (strong coupling for the large field cutoff and
intermediate coupling for the other method). We briefly discuss potential
applications for lattice gauge theory with compact groups (which have a
build-in large field cutoff).

View original: http://arxiv.org/abs/1201.5710