On near-MDS codes and caps

TL;DR

This paper explores new classes of near-MDS codes in projective 3-space derived from geometric configurations like quadrics and twisted cubics, and also constructs complete caps in projective 4-space with specific sizes.

Contribution

It introduces novel near-MDS codes from intersections of geometric objects and constructs complete caps with explicit sizes in higher-dimensional projective spaces.

Findings

Multiple classes of near-MDS codes are described.

Two classes of complete caps with specific sizes are constructed.

Abstract

Several classes of near-MDS codes of ${\rm PG}(3,q)$ are described. They are obtained either by considering the intersection of an elliptic quadric ovoid and a Suzuki-Tits ovoid of a symplectic polar space ${\cal W}(3, q)$ or starting from the $q+1$ points of a twisted cubic of ${\rm PG}(3, q)$. As a by-product two classes of complete caps of ${\rm PG}(4,q)$ of size $2q^2-q \pm \sqrt{2q} + 2$ are exhibited.