Real-space dynamic renormalization group. II. Simple examples

The real-space renormalization-group method for the dynamics of critical phenomena introduced in the previous paper is applied to two calculations within the two-dimensional kinetic Ising model on a triangular lattice. In both cases a cumulant expansion in the intercell couplings is performed. In the first calculation are found the most general first-order recursion relations coupling neighboring cells. From these recursion relations is extracted the dynamic critical exponent $z=1.70\mathrm{}$. While this is a reasonable first-order result, the results for the statics are not as satisfactory. In the second calculation it is shown how the terms that are generated at second order are important in determining the static results. We obtain at second order $z=2.22\mathrm{}$, together with a critical coupling $K_c=0.251\mathrm{}$ and a thermal critical index $\nu =0.950\mathrm{}$.