001package models; 002 003/** 004 * The "sinh-Ising model" is an amalgamation of the sinh-Gordon and the Ising models. 005 * 006 * Its scattering function is <em>minus</em> the sinh-Gordon scattering function: 007 * 008 * \[ S(\zeta) = - \frac{\sinh \zeta - i \sin B \pi/2 }{\sinh \zeta + i \sin B \pi/2 }. \] 009 * 010 * 011 * Correspondingly, the minimal solution is a product of the sinh-Gordon 012 * minimal solution and that of the Ising model, with an additional factor to cancel the double zero at \( \zeta=0 \). 013 * Explicitly, 014 * 015 * \[ F_\text{min}(\theta + i\pi) = \frac{F_\text{min,sinh-Gordon}(\theta + i\pi)}{ \cosh (\theta/2) } . \] 016 * 017 * 018 */ 019public class SinhIsingModel extends IntegrableModel 020{ 021 private SinhGordonModel sg; 022 023 public SinhIsingModel(final double b) { 024 sg = new SinhGordonModel(b); 025 } 026 027 @Override 028 public double FminIpi(double theta) { 029 return sg.FminIpi(theta) / Math.cosh(theta/2.0); 030 } 031 032}