Ising model susceptibility: the Fuchsian differential equation for χ<sup>(4)</sup>and its factorization properties
Ising model susceptibility: the Fuchsian differential equation for χ<sup>(4)</sup>and its factorization properties
We give the Fuchsian linear differential equation satisfied by $\chi^{(4)}$, the ``four-particle'' contribution to the susceptibility of the isotropic square lattice Ising model. This Fuchsian differential equation is deduced from a series expansion method introduced in two previous papers and is applied with some symmetries and tricks specific to $\chi^{(4)}$. …