Arcs with Large Conical Subsets in Desarguesian Planes of Even Order

Abstract

We give an explicit classification of the arcs in PG$(2,q)$ ($q$ even) with a large conical subset and excess 2, i.e., that consist of $q/2+1$ points of a conic and two points not on that conic. Apart from the initial setup, the methods used are similar to those for the case of odd $q$, published earlier (Electronic Journal of Combinatorics, 17, #R112).