CRYSTAL B(infinity) FOR QUANTUM AFFINE ALGEBRAS: A YOUNG WALL DESCRIPTION

Abstract

We study the crystal base B(infinity) associated with the negative part of the quantum group for classical affine Lie algebra types. Using the expression of the crystal B(infinity) as a union of highest weight crystals, we give an explicit description of B(infinity) in terms of Young walls. The new description realizes B(infinity) as a set of certain objects called marginally large walls.