High-precision estimate of the critical exponents for the directed Ising universality class

With extensive Monte Carlo simulations, we present high-precision estimates of the critical exponents of branching annihilating random walks with two offspring, a prototypical model of the directed Ising universality class in one dimension. To estimate the exponents accurately, we propose a systematic method to find corrections to scaling whose leading behavior is supposed to take the form t (-chi) in the long-time limit at the critical point. Our study shows that chi a parts per thousand 0.75 for the number of particles in defect simulations and chi a parts per thousand 0.5 for other measured quantities, which should be compared with the widely used value of chi = 1. Using chi so obtained, we analyze the effective exponents to find that beta/nu (aEuro-) = 0.2872(2), z = 1.7415(5), eta = 0.0000(2), and accordingly, beta/nu (aSyen) = 0.5000(6). Our numerical results for beta/nu (aEuro-) and z are clearly different from the conjectured rational numbers beta/nu (aEuro-) = a parts per thousand 0.2857, z = = 1.75 by Jensen [Phys. Rev. E, 50, 3623 (1994)]. Our result for beta/nu (aSyen), however, is consistent with , which is believed to be exact.