AS-configurations and skew-translation generalised quadrangles

Abstract

The only known skew-translation generalised quadrangles (STGQ) having order $(q,q)$, with $q$ even, are translation generalised quadrangles. Equivalently, the only known groups $G$ of order $q^3$, $q$ even, admitting an Ahrens-Szekeres (AS-)configuration are elementary abelian. In this paper we prove results in the theory of STGQ giving (i) new structural information for a group $G$ admitting an AS-configuration, (ii) a classification of the STGQ of order $(8,8)$, and (iii) a classification of the STGQ of order $(q,q)$ for odd $q$ (using work of Ghinelli and Yoshiara).

A shorter version of this paper will appear in J. Algebra. This arXiv version includes our supporting GAP code in an Appendix. The structure of the proof was modified and Lemma 4.15 was inserted. Some other minor corrections were made