15 research outputs found
Codes and caps from orthogonal Grassmannians
In this paper we investigate linear error correcting codes and projective
caps related to the Grassmann embedding of an orthogonal
Grassmannian . In particular, we determine some of the parameters of
the codes arising from the projective system determined by
. We also study special sets of points of
which are met by any line of in at most 2 points and we
show that their image under the Grassmann embedding is a
projective cap.Comment: Keywords: Polar Grassmannian; dual polar space; embedding; error
correcting code; cap; Hadamard matrix; Sylvester construction (this is a
slightly revised version of v2, with updated bibliography
Line Polar Grassmann Codes of Orthogonal Type
Polar Grassmann codes of orthogonal type have been introduced in I. Cardinali
and L. Giuzzi, \emph{Codes and caps from orthogonal Grassmannians}, {Finite
Fields Appl.} {\bf 24} (2013), 148-169. They are subcodes of the Grassmann code
arising from the projective system defined by the Pl\"ucker embedding of a
polar Grassmannian of orthogonal type. In the present paper we fully determine
the minimum distance of line polar Grassmann Codes of orthogonal type for
odd
Line polar Grassmann codes of orthogonal type
Polar Grassmann codes of orthogonal type have been introduced in I. Cardinali and L. Giuzzi, \emph{Codes and caps from orthogonal Grassmannians}, {Finite Fields Appl.} {\bf 24} (2013), 148-169. They are subcodes of the Grassmann code arising from the projective system defined by the Pl\"ucker embedding of a polar Grassmannian of orthogonal type. In the present paper we fully determine the minimum distance of line polar Grassmann Codes of orthogonal type for q odd
Minimum distance of Symplectic Grassmann codes
We introduce the Symplectic Grassmann codes as projective codes defined by
symplectic Grassmannians, in analogy with the orthogonal Grassmann codes
introduced in [4]. Note that the Lagrangian-Grassmannian codes are a special
class of Symplectic Grassmann codes. We describe the weight enumerator of the
Lagrangian--Grassmannian codes of rank and and we determine the minimum
distance of the line Symplectic Grassmann codes.Comment: Revised contents and biblograph
Intersections of the Hermitian surface with irreducible quadrics in , odd
In , with odd, we determine the possible intersection sizes of
a Hermitian surface and an irreducible quadric
having the same tangent plane at a common point .Comment: 14 pages; clarified the case q=
Intersections of the Hermitian Surface with irreducible Quadrics in even Characteristic
We determine the possible intersection sizes of a Hermitian surface with an irreducible quadric of sharing at least a
tangent plane at a common non-singular point when is even.Comment: 20 pages; extensively revised and corrected version. This paper
extends the results of arXiv:1307.8386 to the case q eve
Implementing Line-Hermitian Grassmann codes
In [I. Cardinali and L. Giuzzi. Line Hermitian Grassmann codes and their
parameters. Finite Fields Appl., 51: 407-432, 2018] we introduced line
Hermitian Grassmann codes and determined their parameters. The aim of this
paper is to present (in the spirit of [I. Cardinali and L. Giuzzi. Enumerative
coding for line polar Grassmannians with applications to codes. Finite Fields
Appl., 46:107-138, 2017]) an algorithm for the point enumerator of a line
Hermitian Grassmannian which can be usefully applied to get efficient encoders,
decoders and error correction algorithms for the aforementioned codes.Comment: 26 page