A note on the Lax pairs for Painleve equations

Citation
Aa. Kapaev et E. Hubert, A note on the Lax pairs for Painleve equations, J PHYS A, 32(46), 1999, pp. 8145-8156
Citations number
28
Categorie Soggetti
Physics
Journal title
JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL
ISSN journal
03054470 → ACNP
Volume
32
Issue
46
Year of publication
1999
Pages
8145 - 8156
Database
ISI
SICI code
0305-4470(19991119)32:46<8145:ANOTLP>2.0.ZU;2-Q
Abstract
For the classical Painleve equations, besides the method of similarity redu ction of Lax pairs for integrable partial differential equations, two ways are known for Lax pair generation. The first is based on the confluence pro cedure in Fuchs' linear ODE with four regular singularities isomonodromy de formation which is governed by the sixth Painleve equation. The second meth od treats the hypergeometric equation and confluent hypergeometric equation s as the isomonodromy deformation equations for the triangular systems of O DEs, in whose non-triangular extensions give rise to the Lax pairs for the Painleve equations. The theory of integrable integral operators suggests a new way of Lax pair generation for the classical Painleve equations. This method involves a spe cial kind of gauge transformation that is applied to linear systems which a re exactly solvable in terms of the classical special functions. Some of th e Lax pairs we introduce are known, others are new. The question of gauge e quivalence of different Lax pairs for the Painleve equations is considered as well.