Quasi type IV codes over a non-unital ring
There is a local ring I of order 4, without identity for the multiplication, defined by generators and relations as I = ⟨ a , b ∣ 2 a = 2 b = 0 , a 2 = b , a b = 0 ⟩ . We give a natural map between linear codes over I and additive codes over F 4 , that allows for efficient computations. We study th...
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Published in | Applicable algebra in engineering, communication and computing Vol. 32; no. 3; pp. 217 - 228 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Berlin/Heidelberg
Springer Berlin Heidelberg
01.06.2021
Springer Nature B.V Springer Verlag |
Subjects | |
Online Access | Get full text |
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Summary: | There is a local ring
I
of order 4, without identity for the multiplication, defined by generators and relations as
I
=
⟨
a
,
b
∣
2
a
=
2
b
=
0
,
a
2
=
b
,
a
b
=
0
⟩
.
We give a natural map between linear codes over
I
and additive codes over
F
4
,
that allows for efficient computations. We study the algebraic structure of linear codes over this non-unital local ring, their generator and parity-check matrices. A canonical form for these matrices is given in the case of so-called nice codes. By analogy with
Z
4
-codes, we define residue and torsion codes attached to a linear
I
-code. We introduce the notion of quasi self-dual codes (QSD) over
I
, and Type IV
I
-codes, that is, QSD codes all codewords of which have even Hamming weight. This is the natural analogue of Type IV codes over the field
F
4
.
Further, we define quasi Type IV codes over
I
as those QSD codes with an even torsion code. We give a mass formula for QSD codes, and another for quasi Type IV codes, and classify both types of codes, up to coordinate permutation equivalence, in short lengths. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 |
ISSN: | 0938-1279 1432-0622 |
DOI: | 10.1007/s00200-021-00488-6 |