English

Prime Power Residue and Linear Coverings of Vector Space over $\mathbb{F}_{q}$

Number Theory 2023-06-19 v1

Abstract

Let qq be an odd prime and B={bj}j=1lB = \{b_{j}\}_{j=1}^{l} be a finite set of nonzero integers that does not contain a perfect qthq^{th} power. We show that BB has a qthq^{th} power modulo every prime pqp \neq q and not dividing bBb\prod_{b\in B} b if and only if BB corrresponds to a linear hyperplane covering of Fqk\mathbb{F}_{q}^{k}. Here, kk is the number of distinct prime factors of the qq-free part of elements of BB. Consequently: (i)(i) a set BZ{0}B \subset\mathbb{Z}\setminus\{0\} with cardinality less than q+1q+1 cannot have a qthq^{th} power modulo almost every prime unless it contains a perfect qthq^{th} power and (ii)(ii) For every set B={bj}j=1lZ{0}B = \{b_{j}\}_{j=1}^{l} \subset\mathbb{Z}\setminus\{0\} and for every (cj)j=1l(Fq{0})l\big(c_{j}\big)_{j=1}^{l} \in\Big(\mathbb{F}_{q}\setminus\{0\}\Big)^{l} the set BB contains a qthq^{th} power modulo every prime pqp \neq q and not dividing j=1l\prod_{j=1}^{l} if and only if the set {bjcj}j=1l\{b_{j}^{c_{j}}\}_{j=1}^{l} does so.

Keywords

Cite

@article{arxiv.2305.01856,
  title  = {Prime Power Residue and Linear Coverings of Vector Space over $\mathbb{F}_{q}$},
  author = {Bhawesh Mishra},
  journal= {arXiv preprint arXiv:2305.01856},
  year   = {2023}
}