001package models; 002 003/** 004 * The Ising model is an integrable model with constant scattering function S=-1. 005 * 006 * Its minimal solution \(F_\text{min}\) is given by \(F_\text{min}(\zeta) = -i \sinh(\zeta/2) \), 007 * which means \(F_\text{min}(\theta+ i \pi) = \cosh(\zeta/2) \). 008 */ 009public class IsingModel extends IntegrableModel 010{ 011 012 @Override 013 public double FminIpi(double theta) { 014 return Math.cosh(theta/2.0); 015 } 016 017}