Toroidal Lie algebras and Bogoyavlensky's 2+1-dimensional equation
Abstract
Description
We introduce an extension of the \ell-reduced KP hierarchy, which we call the \ell-Bogoyavlensky hierarchy. Bogoyavlensky's 2+1-dimensional extension of the KdV equation is the lowest equation of the hierarchy in case of \ell=2. We present a group-theoretic characterization of this hierarchy on the basis of the 2-toroidal Lie algebra sl_\ell^{tor}. This reproduces essentially the same Hirota bilinear equations as those recently introduced by Billig and Iohara et al. We can further derive these Hirota bilinear equation from a Lax formalism of the hierarchy.This Lax formalism also enables us to construct a family of special solutions that generalize the breaking soliton solutions of Bogoyavlensky. These solutions contain the N-soliton solutions, which are usually constructed by use of vertex operators.
Latex2e with amsmath,amssymb, 35 pages, no figures, (v2) typos corrected, added info on ref.[30] (v3) added a reference and some examples (v4) added some comments in subsection 4.4
Latex2e with amsmath,amssymb, 35 pages, no figures, (v2) typos corrected, added info on ref.[30] (v3) added a reference and some examples (v4) added some comments in subsection 4.4