Abstract:
We present new hierarchies of nonlinear ordinary differential equations (ODEs) that are generalizations of the Painlevé equations. These hierarchies contain the Painlevé equations as special cases. We emphasize the sixth-order ODEs. Special solutions for one of them are expressed via the general solutions of the $P_1$ and $P_2$ equations and special cases of the $P_3$ and $P_5$ equations. Four of the six Painlevé equations can be considered special cases of these sixth-order ODEs. We give linear representations for solving the Cauchy problems for the hierarchy equations using the inverse monodromy transform.
Keywords:Painlevé equations, Painlevé transcendents, higher analogues, isomonodromic linear problem.