Surfaces of revolution in terms of solitons

Abstract

The detailed analysis of the generalised Weierstrass representation of surfaces of revolution and their deformations induced by the modified Korteweg--de Vries (mKdV) equations is done. In particular, it is shown that these deformations preserve tori. The geometric meaning of the potential of surface is discussed and the deformations of potentials induced by geometric deformations (the Moebius inversion and a passing to a dual surface) are described. The conjecture of invariance of first integrals of the mKdV hierarchy, considering as invariants of surfaces, with respect to confomal changes of the metric of the ambient space is introduced. Some numeric computations confirming it are also presented. This paper is the sequel to the previous author's paper "Modified Novikov-Veselov equation and differential geometry of surfaces" (dg-ga/9511005) where generic surfaces are considered. Here the surfaces of revolution are regarded as a toy model for the general case.