Small Extended Generalized Quadrangles

We consider extensions of generalized quadrangles with parameters (s, t), and establish lower bounds (in terms of s and t) for the number of points, sometimes under additional hypotheses. We also study the structure of geometries attaining these bounds, give several constructions and some uniqueness proofs, and examine the question of further extensions

Characterization theorems for Zara graphs

We give several characterization theorems ror Zara graphs