Frequency regulators for the nonperturbative renormalization group: A general study and the model A as a benchmark

Published in Phys. Rev. E, 2017

Abstract:

We derive the necessary conditions for implementing a regulator that depends on both momentum and frequency in the nonperturbative renormalization-group flow equations of out-of-equilibrium statistical systems. We consider model A as a benchmark and compute its dynamical critical exponent $z$. This allows us to show that frequency regulators compatible with causality and the fluctuation-dissipation theorem can be devised. We show that when the principle of minimal sensitivity (PMS) is employed to optimize the critical exponents $\eta$, $\nu$, and $z$, the use of frequency regulators becomes necessary to make the PMS a self-consistent criterion.

Recommended citation: "Frequency regulators for the nonperturbative renormalization group: A general study and the model A as a benchmark", C. Duclut, and B. Delamotte, Phys. Rev. E 95, 12107 (2017). http://link.aps.org/doi/10.1103/PhysRevE.95.012107