title: Universal amplitude ratio Gamma-/Gamma+ for two-dimensional percolation.
abstract: The amplitude ratio of the susceptibility (or second size moment) for two-dimensional percolation is calculated by two series methods and also by Monte Carlo simulation. The first series method is an approach based upon integrating approximations to the scaling function. The second series method directly uses low- and high-density series expansions of the susceptibility, going to unprecedented orders for both bond and site percolation on the square lattice. Putting all methods together we find a consistent value Gamma-/Gamma+ = 162.5+/-2 , a significant improvement over previous results that placed the value of this ratio variously in the range of 14 to 220.
authors.affiliation: ARC Centre of Excellence for Mathematics and Statistics of Complex Systems, Department of Mathematics and Statistics, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Iwan
authors.initials: I
authors.lastname: Jensen
authors.forename: Robert M
authors.initials: RM
authors.lastname: Ziff