Majority-vote on directed Barabasi-Albert networks
  On directed Barabasi-Albert networks with two and seven neighbours selected by each added site, the Ising model was seen not to show a spontaneous magnetisation. Instead, the decay time for flipping of the magnetisation followed an Arrhenius law for Metropolis and Glauber algorithms, but for Wolff cluster flipping the magnetisation decayed exponentially with time. On these networks the Majority-vote model with noise is now studied through Monte Carlo simulations. However, in this model, the order-disorder phase transition of the order parameter is well defined in this system. We calculate the value of the critical noise parameter q_c for several values of connectivity z of the directed Barabasi-Albert network. The critical exponents beta/nu., gamma/nu and 1/nu were calculated for several values of z. 
F.W.S. Lima