中文

形式为 $x+\gamma \mathrm{Tr}(H(x))$ 的置换多项式

数论 2025-07-02 v1

摘要

给定 Fqn\mathbb{F}_{q^n} 上的多项式 H(x)H(x),我们研究形式为 x+γTr(H(x))x + \gamma \mathrm{Tr}(H(x))Fqn\mathbb{F}_{q^n} 的置换多项式。设 \]P_H=\{\gamma\in \mathbb{F}_{q^n} : x+\gamma \mathrm{Tr}(H(x))~\text{是置换多项式}\}.\] 我们给出了集合 PHP_H 的一些性质,特别是其与线性翻译器之间的关系。此外,我们获得了集合 PHP_H 基数的一个有效上界,表明该上界可达到 qnqn1q^n - q^{n - 1}。 Furthermore, we prove that when the cardinality of the set PHP_H reaches this upper bound, the function Tr(H(x))\mathrm{Tr}(H(x)) must be an Fq\mathbb{F}_q-linear function. Finally, we study two classes of functions H(x)H(x) over Fq2\mathbb{F}_{q^2} and determine the corresponding sets PHP_H. The sizes of these sets PHP_H are all relatively small, even only including the trivial case.

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引用

@article{arxiv.2507.00781,
  title  = {Permutation polynomials of the form $x+\gamma \mathrm{Tr}(H(x))$},
  author = {Yangcheng Li and Xuan Pang and Pingzhi Yuan and Yuanpeng Zeng},
  journal= {arXiv preprint arXiv:2507.00781},
  year   = {2025}
}