Nonperturbative renormalization group approach to the Ising model:: A derivative expansion at order partial derivative4 -: art. no. 064421

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 partial derivative(4) of the derivative expansion leads to nu=0.632 and to an anomalous dimension eta=0.033 which is significantly improved compared with lower orders calculations.