31,931 research outputs found
Majority-vote on directed Small-World networks
On directed Small-World networks the
Majority-vote model with noise is now studied through Monte Carlo
simulations. 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 rewiring probability p of
the directed Small-World network. The critical exponentes beta/nu, gamma/nu and
1/nu were calculated for several values of p.Comment: 16 pages including 9 figures, for Int. J. Mod. Phys.
Critical behavior of the spin-3/2 Blume-Capel model on a random two-dimensional lattice
We investigate the critical properties of the spin-3/2 Blume-Capel model in
two dimensions on a random lattice with quenched connectivity disorder. The
disordered system is simulated by applying the cluster hybrid Monte Carlo
update algorithm and re-weighting techniques. We calculate the critical
temperature as well as the critical point exponents , ,
, and . We find that, contrary of what happens to the spin-1/2
case, this random system does not belong to the same universality class as the
regular two-dimensional ferromagnetic model.Comment: 5 pages and 5 figure
Ising model spin S=1 on directed Barabasi-Albert networks
On directed Barabasi-Albert networks with two and seven neighbours selected
by each added site, the Ising model with spin S=1/2 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
Ising model spin S=1 is now studied through Monte Carlo simulations.
However, in this model, the order-disorder phase transition is well defined
in this system. We have obtained a first-order phase transition for values of
connectivity m=2 and m=7 of the directed Barabasi-Albert network.Comment: 8 pages for Int. J. Mod. Phys. C; e-mail: [email protected]
Simulation of majority rule disturbed by power-law noise on directed and undirected Barabasi-Albert networks
On directed and undirected Barabasi-Albert networks the Ising model with spin
S=1/2 in the presence of a kind of noise is now studied through Monte Carlo
simulations. The noise spectrum P(n) follows a power law, where P(n) is the
probability of flipping randomly select n spins at each time step. The noise
spectrum P(n) is introduced to mimic the self-organized criticality as a model
influence of a complex environment. In this model, different from the square
lattice, the order-disorder phase transition of the order parameter is not
observed. For directed Barabasi-Albert networks the magnetisation tends to zero
exponentially and for undirected Barabasi-Albert networks, it remains constant.Comment: 6 pages including many figures, for Int. J. Mod. Phys.
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