Asymptotic safety: A simple example

作者：Braun Jens^*; Gies Holger; Scherer Daniel D

来源：Physical Review D - Particles, Fields, Gravitation and Cosmology, 2011, 83(8): 085012.

DOI：10.1103/PhysRevD.83.085012

We use the Gross-Neveu model in 2 < d < 4 as a simple fermionic example for Weinberg's asymptotic safety scenario: despite being perturbatively nonrenormalizable, the model defines an interacting quantum field theory being valid to arbitrarily high momentum scales owing to the existence of a non-Gaussian fixed point. Using the functional renormalization group, we study the uv behavior of the model in both the purely fermionic as well as a partially bosonized language. We show that asymptotic safety is realized at non-Gaussian fixed points in both formulations, the universal critical exponents of which we determine quantitatively. The partially bosonized formulation allows to make contact to the large-N-f expansion where the model is known to be renormalizable to all orders. In this limit, the fixed-point action as well as all universal critical exponents can be computed analytically. As asymptotic safety has become an important scenario for quantizing gravity, our description of a well-understood model is meant to provide for an easily accessible and controllable example of modern nonperturbative quantum field theory.

• 出版日期2011-4-11