A recent paper of O’Reilly Regueiro obtained an explicit upper bound on the number of points of a flagtransitive, point-imprimitive, symmetric design in terms of the number of blocks containing two points. We improve that upper bound and give a complete list of feasible parameter sequences for such designs for which two points lie in at most ten blocks. Classifications are available for some of...

Spreads of orthogonal vector spaces are used to construct many translation planes of even order q, for odd m > 1, having a collineation with a (q − 1)-cycle on the line at infinity and on each of two affine lines.

let $g$ be an automorphism group of a‎ ‎$2$-$(v,k,4)$ symmetric design $mathcal d$‎. ‎in this paper‎, ‎we‎ ‎prove that if $g$ is flag-transitive point-primitive‎, ‎then the‎ ‎socle of $g$ cannot be an exceptional group of lie type‎.

A polygon A in a configuration C is called rotary if C admits an automorphism which acts upon A as a one-step rotation. We study rotary polygons and their orbits under the group of automorphisms (and antimorphisms) of C. We determine the number of such orbits for several symmetry types of rotary polygons in the case when C is flag-transitive. As an example, we provide tables of flag-transitive ...