López Eduardo, Buldyrev Sergey V, Braunstein Lidia A, Havlin Shlomo, Stanley H Eugene
Center for Polymer Studies, Boston University, Boston, Massachusetts 02215, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Nov;72(5 Pt 2):056131. doi: 10.1103/PhysRevE.72.056131. Epub 2005 Nov 28.
We study the behavior of the optimal path between two sites separated by a distance on a d-dimensional lattice of linear size L with weight assigned to each site. We focus on the strong disorder limit, i.e., when the weight of a single site dominates the sum of the weights along each path. We calculate the probability distribution P(l opt/r,L) of the optimal path length l opt, and find for r <<L a power-law decay with l opt, characterized by exponent g opt. We determine the scaling form of P(l opt/r,L) in two- and three-dimensional lattices. To test the conjecture that the optimal paths in strong disorder and flow in percolation clusters belong to the same universality class, we study the tracer path length l tr of tracers inside percolation through their probability distribution P(l tr/r,L). We find that, because the optimal path is not constrained to belong to a percolation cluster, the two problems are different. However, by constraining the optimal paths to remain inside the percolation clusters in analogy to tracers in percolation, the two problems exhibit similar scaling properties.
我们研究在一个线性尺寸为(L)的(d)维晶格上,两个相距一定距离的位点之间最优路径的行为,其中每个位点都被赋予了权重。我们关注强无序极限情况,即当单个位点的权重主导每条路径上权重之和时的情况。我们计算最优路径长度(l_{opt})的概率分布(P(l_{opt}/r,L)),并发现当(r\ll L)时,(l_{opt})呈现幂律衰减,其特征指数为(g_{opt})。我们确定了二维和三维晶格中(P(l_{opt}/r,L))的标度形式。为了检验强无序中的最优路径与渗流团簇中的流动属于同一普适类这一猜想,我们通过其概率分布(P(l_{tr}/r,L))研究渗流中示踪剂的示踪路径长度(l_{tr})。我们发现,由于最优路径并不局限于属于渗流团簇,所以这两个问题是不同的。然而,通过类似于渗流中示踪剂的方式,将最优路径限制在渗流团簇内部,这两个问题呈现出相似的标度性质。