TOPICS
Search

s-Cluster


An s-cluster in a random n×n (0,1)-matrix whose entries independently equal 1 (with probability p) or 0 (with probability q=1-p) is a connected component of s 1s, using horizontal or vertical nearest-neighbor adjacency. Here n and s are positive integers and 0<=p<=1. The numbers of n×n (0,1)-matrices with k site clusters for k=0, 1, ... are summarized in the following table (OEIS A086266).

nmatrices with k=0, 1, ... clusters
11, 1
21, 13, 2
31, 218, 208, 78, 6, 1
41, 11506, 21172, 20262, 9560, 2593, 408, 32, 2

For p=1/2, this gives the mean total numbers of site clusters for n=1, 2, ... as 1/2, 17/16, 897/512, 168529/65536, ... (numerators OEIS A086265).

Let C_n(p) be the total number of clusters in this site percolation model. Then the value

 K_S(p)=lim_(n->infty)(<C_n(p)>)/(n^2),

called the mean cluster count per site or mean cluster density, exists, where <C_n(p)> is the expectation value of C_n(p). Numerically, it is found that

 K_S(1/2) approx 0.065770...

(OEIS A086268; Ziff et al. 1997).


See also

b-Cluster, Connected Component, Percolation Theory, s-Run, Site Percolation, Truchet Tiling

Explore with Wolfram|Alpha

References

Finch, S. R. "Percolation Cluster Density Constants." §5.18 in Mathematical Constants. Cambridge, England: Cambridge University Press, pp. 371-378, 2003.Sloane, N. J. A. Sequences A086265, A086266, and A086268 in "The On-Line Encyclopedia of Integer Sequences."Temperley, H. N. V. and Lieb, E. H. "Relations Between the 'Percolation' and 'Colouring' Problem and Other Graph-Theoretical Problems Associated with Regular Planar Lattices; Some Exact Results for the 'Percolation' Problem." Proc. Roy. Soc. London A 322, 251-280, 1971.Ziff, R. M.; Finch, S. R.; and Adamchik, V. S. "Universality of Finite-Size Corrections to the Number of Critical Percolation Clusters." Phys. Rev. Lett. 79, 3447-3450, 1997. https://doi.org/10.1103/PhysRevLett.79.3447.

Referenced on Wolfram|Alpha

s-Cluster

Cite this as:

Weisstein, Eric W. "s-Cluster." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/s-Cluster.html

Subject classifications