Beyond CFT : Deformed Virasoro and Elliptic Algebras

Abstract

In this lecture we discuss `beyond CFT' from symmetry point of view. After reviewing the Virasoro algebra, we introduce deformed Virasoro algebras and elliptic algebras. These algebras appear in solvable lattice models and we study them by free field approach.

134 pages, 2 figures, (AMS-)LaTeX(2e), Lecture given at 1999 CRM Summer School ``Theoretical Physics at the End of the XXth Century'', June 27 - July 10, Banff (Alberta), Canada ; References are added and misprints are corrected (See a list of revised points in the last page)