arXiv subjects

Raul Antonio Ferraz

Publications and source records attributed to Raul Antonio Ferraz.

3 recordsLinked to original sources

arXiv2023

Minimal group codes over alternating groups

In this work we show that every minimal code in a semisimple group algebra $\mathbb{F}_qG$ is essential if $G$ is a simple group. Since the alternating group $A_n$ is simple if $n=3$ or $n\geq 5$, we present some examples of minimal codes in $\mathbb{F}_qA_n$. For this purpose, if $char(\mathbb{F}_q)> n$, we present the Wedderburn-Artin decomposition of $\mathbb{F}_qS_n$ and $\mathbb{F}_qA_n$ and explicit some of the centrally primitive idempotents of $\mathbb{F}_qS_n$ and $\mathbb{F}_qA_n$.

math.RA↗

arXiv2013

Units of $\mathbb{Z}C_{p^n}$

Let $p$ be a prime integer and $n,i$ be positive integers such that \linebreak $S=\{-1, \ θ, \ μ_i=1+θ+... + θ^{i-1} \ \mid 1 < i < \frac{p^n}{2}, \ gcd(p^n,i)=1 \}$ generates the group of units of $\mathbb{Z}[θ],$ where $θ$ is a primitive ${p^n}$--$th$ root of unity. Denote by $C_{p^n}$ the cyclic group of order $p^n.$ In this paper we describe explicitly a multiplicatively independent set which generates a complement to $\pm C_{p^n}$ in the group of units of the integral group ring of $C_{p^n}.$

math.GR↗

arXiv2012

G-equivalence in group algebras and minimal abelian codes

Let G be a finite abelian group and F a field such that char(F) does not divide |G|. Denote by FG the group algebra of G over F. A (semisimple) abelian code is an ideal of FG. Two codes I and J of FG are G-equivalent if there exists an automorphism of G whose linear extension to FG maps I onto J In this paper we give a necessary and sufficient condition for minimal abelian codes to be G-equivalent and show how to correct some results in the literature.

cs.IT↗