Nonstandard linear recurring sequence subgroups in finite fields and automorphisms of cyclic codes
| dc.creator | Hollmann, Henk D. L. | |
| dc.date | 2008-07-03 | |
| dc.date.accessioned | 2026-07-07T09:48:16Z | |
| dc.date.available | 2026-07-07T09:48:16Z | |
| dc.description | Let $q=p^r$ be a prime power, and let $f(x)=x^m-\gs_{m-1}x^{m-1}- >...-\gs_1x-\gs_0$ be an irreducible polynomial over the finite field $\GF(q)$ of size $q$. A zero $ξ$ of $f$ is called {\em nonstandard (of degree $m$) over $\GF(q)$} if the recurrence relation $u_m=\gs_{m-1}u_{m-1} + ... + \gs_1u_1+\gs_0u_0$ with characteristic polynomial $f$ can generate the powers of $ξ$ in a nontrivial way, that is, with $u_0=1$ and $f(u_1)\neq 0$. In 2003, Brison and Nogueira asked for a characterisation of all nonstandard cases in the case $m=2$, and solved this problem for $q$ a prime, and later for $q=p^r$ with $r\leq4$. In this paper, we first show that classifying nonstandard finite field elements is equivalent to classifying those cyclic codes over $\GF(q)$ generated by a single zero that posses extra permutation automorphisms. Apart from two sporadic examples of degree 11 over $\GF(2)$ and of degree 5 over $\GF(3)$, related to the Golay codes, there exist two classes of examples of nonstandard finite field elements. One of these classes (type I) involves irreducible polynomials $f$ of the form $f(x)=x^m-f_0$, and is well-understood. The other class (type II) can be obtained from a primitive element in some subfield by a process that we call extension and lifting. We will use the known classification of the subgroups of $\PGL(2,q)$ in combination with a recent result by Brison and Nogueira to show that a nonstandard element of degree two over $\GF(q)$ necessarily is of type I or type II, thus solving completely the classification problem for the case $m=2$. | |
| dc.identifier | https://arxiv.org/abs/0807.0595 | |
| dc.identifier | http://arxiv.org/abs/0807.0595 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/164150 | |
| dc.subject | Information Theory | |
| dc.subject | Discrete Mathematics | |
| dc.subject | Combinatorics | |
| dc.subject | E.4 | |
| dc.title | Nonstandard linear recurring sequence subgroups in finite fields and automorphisms of cyclic codes | |
| dc.type | text |