Nonperturbative renormalization group approach to the Ising model: A derivative expansion at order∂4

Abstract

On the example of the three-dimensional Ising model, we show that nonperturbative renormalization group equations allow one to obtain very accurate critical exponents. Implementing the order ${\ensuremath{\partial}}^{4}$ of the derivative expansion leads to $\ensuremath{\nu}=0.632$ and to an anomalous dimension $\ensuremath{\eta}=0.033$ which is significantly improved compared with lower orders calculations.