Anıl Tunç

Parabolic coset algebras of W(H4), the Schur index of a character of degree 48, and non-commutative association schemes on the edges and cells of the 600-cell

We study the rational parabolic coset algebras of the Coxeter group W(H4), the symmetry group of the 600-cell. Of the 34 irreducible characters of W(H4), exactly one, the rational character of degree 48, has Schur index greater than 1 over Q; its index is 2 and the corresponding...