English

On pairs of $r$-primitive and $k$-normal elements with prescribed traces over finite fields

Number Theory 2023-07-26 v2

Abstract

Given Fqn\mathbb{F}_{q^{n}}, a field with qnq^n elements, where qq is a prime power and nn is positive integer. For r1,r2,m1,m2Nr_1,r_2,m_1,m_2 \in \mathbb{N}, k1,k2N{0}k_1,k_2 \in \mathbb{N}\cup \{0\}, a rational function F=F1F2F = \frac{F_1}{F_2} in Fq[x]\mathbb{F}_{q}[x] with deg(FiF_i) mi\leq m_i; i=1,2,i=1,2, satisfying some conditions, and a,bFqa,b \in \mathbb{F}_{q}, we construct a sufficient condition on (q,n)(q,n) which guarantees the existence of an r1r_1-primitive, k1k_1-normal element ϵFqn\epsilon \in \mathbb{F}_{q^n} such that F(ϵ)F(\epsilon) is r2r_2-primitive, k2k_2-normal with TrFqn/Fq(ϵ)=a\operatorname{Tr}_{\mathbb{F}_{q^n}/\mathbb{F}_q}(\epsilon) = a and TrFqn/Fq(ϵ1)=b\operatorname{Tr}_{\mathbb{F}_{q^n}/\mathbb{F}_q}(\epsilon^{-1}) = b. For m1=10,  m2=11,  r1=3,  r2=2,  k1=2,  k2=1m_1=10, \; m_2=11,\; r_1 = 3, \; r_2 = 2, \; k_1=2,\;k_2 = 1, we establish bounds on qq, for various nn, to determine the existence of such elements in Fqn\mathbb{F}_{q^{n}}. Furthermore, we identify all such pairs (q,n)(q,n) excluding 10 possible values of (q,n)(q,n), in fields of characteristics 13.

Keywords

Cite

@article{arxiv.2304.08749,
  title  = {On pairs of $r$-primitive and $k$-normal elements with prescribed traces over finite fields},
  author = {Aakash Choudhary and R. K. Sharma},
  journal= {arXiv preprint arXiv:2304.08749},
  year   = {2023}
}