Nonexistence of generalized quadrangles admitting a point-primitive and line-primitive automorphism group with socle $\mathrm{PSU}(3,q)$, $q\ge 3$

Abstract

A central problem in the study of generalized quadrangles is to classify finite generalized quadrangles satisfying certain symmetry conditions. It is known that an automorphism group of a finite thick generalized quadrangle $\mathcal{S}$ acting primitively on both the points and lines of $\mathcal{S}$ must be almost simple. In this paper, we initiate the study of finite generalized quadrangles admitting a point-primitive and line-primitive automorphism group with socle being a unitary group. We develop a group-theoretic tool to prove that the socle of such a group cannot be $\mathrm{PSU}(3,q)$ with $q\ge 3$.

arXiv comment21 pages