ISSN:
1572-9613
Schlagwort(e):
Percolation
;
renormalization
;
universality
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Physik
Notizen:
Abstract In a position-space renormalization group (PSRG) approach to percolation one calculates the probabilityR(p,b) that a finite lattice of linear sizeb percolates, wherep is the occupation probability of a site or bond. A sequence of percolation thresholdsp c (b) is then estimated fromR(p c ,b)=p c (b) and extrapolated to the limitb→∞ to obtainp c =p c (∞). Recently, it was shown that for a certain spanning rule and boundary condition,R(p c ,∞)=R c is universal, and sincep c is not universal, the validity of PSRG approaches was questioned. We suggest that the equationR(p c ,b)=α, where α isany number in (0,1), provides a sequence ofp c (b)'s thatalways converges top c asb→∞. Thus, there is anenvelope from any point inside of which one can converge top c . However, the convergence is optimal if α=R c . By calculating the fractal dimension of the sample-spanning cluster atp c , we show that the same is true aboutany critical exponent of percolation that is calculated by a PSRG method. Thus PSRG methods are still a useful tool for investigating percolation properties of disordered systems.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF02183708
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