The critical group of the Kneser graph on $2$-subsets of an $n$-element set

Abstract

In this paper we compute the critical group of the Kneser graph $KG(n,2)$. This is equivalent to computing the Smith normal form of a Laplacian matrix of this graph.

The statement of Lemma 2.2, part (4) was missing a case. This has been corrected, and it has no effect on the rest of the paper