Quasi-periodic solutions of the universal hierarchy

Abstract

We construct quasi-periodic solutions of the universal hierarchy which includes the multi-component KP and Toda hierarchies and show how they fit into the bilinear formalism. The tau-function is expressed in terms of the Riemann theta-function multiplied by exponential function of a quadratic form in the hierarchical times.

21 pages, no figures. arXiv admin note: text overlap with arXiv:2304.05108