Combinatorial Hopf algebras and Towers of Algebras - Dimension, Quantization, and Functoriality

TL;DR

This paper explores the structure of towers of algebras that form graded dual Hopf algebras, establishing a dimension formula, proposing a classification for a special case, and examining quantum analogs and categorification.

Contribution

It applies axiomatic and combinatorial constructions to classify and analyze towers of algebras with Hopf algebra structures, including a dimension formula and conjectural classification.

Findings

Dimension of algebra towers is r^n n! when forming graded dual Hopf algebras.

For r=1, a conjectural classification of such towers is proposed.

The paper discusses quantum versions and categorification of the algebraic structures.

Abstract

Bergeron and Li have introduced a set of axioms which guarantee that the Grothendieck groups of a tower of algebras $\bigoplus_{n\ge0}A_n$ can be endowed with the structure of graded dual Hopf algebras. Hivert and Nzeutzhap, and independently Lam and Shimozono constructed dual graded graphs from primitive elements in Hopf algebras. In this paper we apply the composition of these constructions to towers of algebras. We show that if a tower $\bigoplus_{n\ge0}A_n$ gives rise to graded dual Hopf algebras then we must have $\dim(A_n)=r^nn!$ where $r = \dim(A_1)$. In the case $r=1$ we give a conjectural classification. We then investigate a quantum version of the main theorem. We conclude with some open problems and a categorification of the construction. This paper is a full version of the summary arXiv: 0710.3744.