2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/148297This is mainly a brief review of some key achievements in a `hot'' area of theoretical and mathematical physics. The principal aim is to outline the basic structures underlying {\em integrable} quantum field theory models with {\em infinite-dimensional} symmetry groups which display a radically new type of {\em quantum group} symmetries. Certain particular aspects are elaborated upon with some detail: integrable systems of Kadomtsev-Petviashvili type and their reductions appearing in matrix models of strings; Hamiltonian approach to Lie-Poisson symmetries; quantum field theory approach to two-dimensional relativistic integrable models with dynamically broken conformal invariance. All field-theoretic models in question are of primary relevance to diverse branches of physics ranging from nonlinear hydrodynamics to string theory of fundamental particle interactions at ultra-high energies.(to appear in "Mathematical Physics Towards the XXIst Century", Proc. Int. Conf. in Beer Sheva, March 1993), LaTeX, 25 pages, BGU-93/22/October-PH (added discussion of generalized Miura transformation for multi-boson KP hierarchies)High Energy Physics - Theorytext