Pub Date : 2024-10-31DOI: 10.1016/j.ffa.2024.102534
Jiayuan Zhang, Xiaoshan Kai, Ping Li
The construction of self-orthogonal codes is an interesting topic due to their wide applications in communication and cryptography. In this paper, we construct several families of self-orthogonal cyclic codes with length , where and is odd. It is proved that there exist q-ary self-orthogonal cyclic codes with parameters for even prime power q, and or for odd prime power q, where d is significantly better than the square-root bound. These several families of self-orthogonal cyclic codes contain some optimal linear codes.
{"title":"Self-orthogonal cyclic codes with good parameters","authors":"Jiayuan Zhang, Xiaoshan Kai, Ping Li","doi":"10.1016/j.ffa.2024.102534","DOIUrl":"10.1016/j.ffa.2024.102534","url":null,"abstract":"<div><div>The construction of self-orthogonal codes is an interesting topic due to their wide applications in communication and cryptography. In this paper, we construct several families of self-orthogonal cyclic codes with length <span><math><mi>n</mi><mo>=</mo><mfrac><mrow><msup><mrow><mi>q</mi></mrow><mrow><mi>m</mi></mrow></msup><mo>−</mo><mn>1</mn></mrow><mrow><mi>λ</mi></mrow></mfrac></math></span>, where <span><math><mi>λ</mi><mo>|</mo><mi>q</mi><mo>−</mo><mn>1</mn></math></span> and <span><math><mi>m</mi><mo>≥</mo><mn>3</mn></math></span> is odd. It is proved that there exist <em>q</em>-ary self-orthogonal cyclic codes with parameters <span><math><mo>[</mo><mi>n</mi><mo>,</mo><mfrac><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac><mo>,</mo><mo>≥</mo><mi>d</mi><mo>]</mo></math></span> for even prime power <em>q</em>, and <span><math><mo>[</mo><mi>n</mi><mo>,</mo><mfrac><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></mfrac><mo>−</mo><mn>1</mn><mo>,</mo><mo>≥</mo><mi>d</mi><mo>]</mo></math></span> or <span><math><mo>[</mo><mi>n</mi><mo>,</mo><mfrac><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac><mo>,</mo><mo>≥</mo><mi>d</mi><mo>]</mo></math></span> for odd prime power <em>q</em>, where <em>d</em> is significantly better than the square-root bound. These several families of self-orthogonal cyclic codes contain some optimal linear codes.</div></div>","PeriodicalId":50446,"journal":{"name":"Finite Fields and Their Applications","volume":"101 ","pages":"Article 102534"},"PeriodicalIF":1.2,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-31DOI: 10.1016/j.ffa.2024.102535
Yanan Wu, Yanbin Pan
Linear codes with few weights have wide applications in consumer electronics, data storage system and secret sharing. In this paper, by virtue of planar functions, several infinite families of l-weight linear codes over are constructed, where l can be any positive integer and p is a prime number. The weight distributions of these codes are determined completely by utilizing certain approach on exponential sums. Experiments show that some (almost) optimal codes in small dimensions can be produced from our results. Moreover, the related covering codes are also investigated.
权重较小的线性编码在消费类电子产品、数据存储系统和秘密共享中有着广泛的应用。本文利用平面函数,构建了多个 Fp 上 l 权重线性编码的无穷族,其中 l 可以是任意正整数,p 是素数。这些编码的权重分布完全是通过利用指数和的某些方法确定的。实验表明,根据我们的结果可以生成一些(几乎)小维度的最优编码。此外,我们还研究了相关的覆盖码。
{"title":"Linear codes from planar functions and related covering codes","authors":"Yanan Wu, Yanbin Pan","doi":"10.1016/j.ffa.2024.102535","DOIUrl":"10.1016/j.ffa.2024.102535","url":null,"abstract":"<div><div>Linear codes with few weights have wide applications in consumer electronics, data storage system and secret sharing. In this paper, by virtue of planar functions, several infinite families of <em>l</em>-weight linear codes over <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> are constructed, where <em>l</em> can be any positive integer and <em>p</em> is a prime number. The weight distributions of these codes are determined completely by utilizing certain approach on exponential sums. Experiments show that some (almost) optimal codes in small dimensions can be produced from our results. Moreover, the related covering codes are also investigated.</div></div>","PeriodicalId":50446,"journal":{"name":"Finite Fields and Their Applications","volume":"101 ","pages":"Article 102535"},"PeriodicalIF":1.2,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-31DOI: 10.1016/j.ffa.2024.102538
Jinjoo Yoo , Yoonjin Lee
We improve the Hasse-Weil-Serre bound over a global function field K with relatively large genus in terms of the ramification behavior of the finite places and the infinite places for , where k is the rational function field . Furthermore, we improve the Hasse-Weil-Serre bound over a global function field K in terms of the defining equation of K. As an application of our main result, we apply our bound to some well-known extensions: Kummer extensions and elementary abelian p-extensions, where p is the characteristic of k. In fact, elementary abelian p-extensions include Artin-Schreier type extensions, Artin-Schreier extensions, and Suzuki function fields. Moreover, we present infinite families of global function fields for Kummer extensions, Artin-Schreier type extensions, and elementary abelian p-extensions but not Artin-Schreier type extensions, which meet our improved bound: our bound is a sharp bound in these families. We also compare our new bound with some known data given in manypoints.org, which is the database on the rational points of algebraic curves. This comparison shows a meaningful improvement of our results on the bound of the number of the rational places of K.
我们从 K/k 的有限位置和无限位置(k 为有理函数域 Fq(T))的柱化行为出发,改进了具有相对大属的全局函数域 K 上的 Hasse-Weil-Serre 定界。此外,我们还根据 K 的定义方程改进了全局函数域 K 的哈塞-韦尔-塞雷约束:库默扩展和初等无边 p 扩展,其中 p 是 k 的特征。事实上,初等无边 p 扩展包括阿尔丁-施莱尔类型扩展、阿尔丁-施莱尔扩展和铃木函数域。此外,我们还提出了库默扩展、阿廷-施莱尔型扩展和初等常方差 p 扩展的全局函数场无穷族,但不包括阿廷-施莱尔型扩展,它们都符合我们的改进约束:在这些族中,我们的约束是一个尖锐的约束。我们还将我们的新约束与 manypoints.org 中给出的一些已知数据进行了比较,后者是关于代数曲线有理点的数据库。比较结果表明,我们对 K 的有理点数的界值进行了有意义的改进。
{"title":"Improvements of the Hasse-Weil-Serre bound over global function fields","authors":"Jinjoo Yoo , Yoonjin Lee","doi":"10.1016/j.ffa.2024.102538","DOIUrl":"10.1016/j.ffa.2024.102538","url":null,"abstract":"<div><div>We improve the Hasse-Weil-Serre bound over a global function field <em>K</em> with relatively large genus in terms of the ramification behavior of the finite places and the infinite places for <span><math><mi>K</mi><mo>/</mo><mi>k</mi></math></span>, where <em>k</em> is the rational function field <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>q</mi></mrow></msub><mo>(</mo><mi>T</mi><mo>)</mo></math></span>. Furthermore, we improve the Hasse-Weil-Serre bound over a global function field <em>K</em> in terms of the defining equation of <em>K</em>. As an application of our main result, we apply our bound to some well-known extensions: <em>Kummer extensions</em> and <em>elementary abelian p-extensions</em>, where <em>p</em> is the characteristic of <em>k</em>. In fact, elementary abelian <em>p</em>-extensions include <em>Artin-Schreier type extensions</em>, <em>Artin-Schreier extensions</em>, and <em>Suzuki function fields</em>. Moreover, we present infinite families of global function fields for Kummer extensions, Artin-Schreier type extensions, and elementary abelian <em>p</em>-extensions but not Artin-Schreier type extensions, which meet our improved bound: our bound is a sharp bound in these families. We also compare our new bound with some known data given in <span><span>manypoints.org</span><svg><path></path></svg></span>, which is the database on the rational points of algebraic curves. This comparison shows a meaningful improvement of our results on the bound of the number of the rational places of <em>K</em>.</div></div>","PeriodicalId":50446,"journal":{"name":"Finite Fields and Their Applications","volume":"101 ","pages":"Article 102538"},"PeriodicalIF":1.2,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-31DOI: 10.1016/j.ffa.2024.102533
Li-Yuan Wang , Hai-Liang Wu
In 2019, Zhi-Wei Sun posed an interesting conjecture on certain determinants with Legendre symbol entries. In this paper, by using the arithmetic properties of p-th cyclotomic field and the finite field , we confirm this conjecture.
{"title":"On the cyclotomic field Q(e2πi/p) and Zhi-Wei Sun's conjecture on det Mp","authors":"Li-Yuan Wang , Hai-Liang Wu","doi":"10.1016/j.ffa.2024.102533","DOIUrl":"10.1016/j.ffa.2024.102533","url":null,"abstract":"<div><div>In 2019, Zhi-Wei Sun posed an interesting conjecture on certain determinants with Legendre symbol entries. In this paper, by using the arithmetic properties of <em>p</em>-th cyclotomic field and the finite field <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>, we confirm this conjecture.</div></div>","PeriodicalId":50446,"journal":{"name":"Finite Fields and Their Applications","volume":"101 ","pages":"Article 102533"},"PeriodicalIF":1.2,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-30DOI: 10.1016/j.ffa.2024.102537
Jinmei Fan , Xiangyong Zeng
Optimal cyclic codes have received a lot of attention and much progress has been made. However, little is known about optimal quinary cyclic codes. In this paper, by analyzing irreducible factors of certain polynomials over finite fields and utilizing multivariate method, three classes of optimal quinary cyclic codes with parameters and three zeros are presented.
{"title":"Optimal quinary cyclic codes with three zeros","authors":"Jinmei Fan , Xiangyong Zeng","doi":"10.1016/j.ffa.2024.102537","DOIUrl":"10.1016/j.ffa.2024.102537","url":null,"abstract":"<div><div>Optimal cyclic codes have received a lot of attention and much progress has been made. However, little is known about optimal quinary cyclic codes. In this paper, by analyzing irreducible factors of certain polynomials over finite fields and utilizing multivariate method, three classes of optimal quinary cyclic codes with parameters <span><math><mo>[</mo><msup><mrow><mn>5</mn></mrow><mrow><mi>m</mi></mrow></msup><mo>−</mo><mn>1</mn><mo>,</mo><msup><mrow><mn>5</mn></mrow><mrow><mi>m</mi></mrow></msup><mo>−</mo><mn>2</mn><mi>m</mi><mo>−</mo><mn>2</mn><mo>,</mo><mn>4</mn><mo>]</mo></math></span> and three zeros are presented.</div></div>","PeriodicalId":50446,"journal":{"name":"Finite Fields and Their Applications","volume":"101 ","pages":"Article 102537"},"PeriodicalIF":1.2,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-23DOI: 10.1016/j.ffa.2024.102521
Guilherme Dias , Saeed Tafazolian , Jaap Top
This paper studies curves defined using Chebyshev polynomials over finite fields. Given the hyperelliptic curve corresponding to the equation , the prime powers are determined such that is separable and is maximal over . This extends a result from [30] that treats the special cases as well as d a prime number. In particular a proof of [30, Conjecture 1.7] is presented. Moreover, we give a complete description of the pairs such that the projective closure of the plane curve defined by is smooth and maximal over .
A number of analogous maximality results are discussed.
{"title":"On certain maximal curves related to Chebyshev polynomials","authors":"Guilherme Dias , Saeed Tafazolian , Jaap Top","doi":"10.1016/j.ffa.2024.102521","DOIUrl":"10.1016/j.ffa.2024.102521","url":null,"abstract":"<div><div>This paper studies curves defined using Chebyshev polynomials <span><math><msub><mrow><mi>φ</mi></mrow><mrow><mi>d</mi></mrow></msub><mo>(</mo><mi>x</mi><mo>)</mo></math></span> over finite fields. Given the hyperelliptic curve <span><math><mi>C</mi></math></span> corresponding to the equation <span><math><msup><mrow><mi>v</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>=</mo><msub><mrow><mi>φ</mi></mrow><mrow><mi>d</mi></mrow></msub><mo>(</mo><mi>u</mi><mo>)</mo></math></span>, the prime powers <span><math><mi>q</mi><mo>≡</mo><mn>3</mn><mspace></mspace><mrow><mi>mod</mi></mrow><mspace></mspace><mn>4</mn></math></span> are determined such that <span><math><msub><mrow><mi>φ</mi></mrow><mrow><mi>d</mi></mrow></msub><mo>(</mo><mi>x</mi><mo>)</mo></math></span> is separable and <span><math><mi>C</mi></math></span> is maximal over <span><math><msub><mrow><mi>F</mi></mrow><mrow><msup><mrow><mi>q</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></msub></math></span>. This extends a result from <span><span>[30]</span></span> that treats the special cases <span><math><mn>2</mn><mo>|</mo><mi>d</mi></math></span> as well as <em>d</em> a prime number. In particular a proof of <span><span>[30, Conjecture 1.7]</span></span> is presented. Moreover, we give a complete description of the pairs <span><math><mo>(</mo><mi>d</mi><mo>,</mo><mi>q</mi><mo>)</mo></math></span> such that the projective closure of the plane curve defined by <span><math><msup><mrow><mi>v</mi></mrow><mrow><mi>d</mi></mrow></msup><mo>=</mo><msub><mrow><mi>φ</mi></mrow><mrow><mi>d</mi></mrow></msub><mo>(</mo><mi>u</mi><mo>)</mo></math></span> is smooth and maximal over <span><math><msub><mrow><mi>F</mi></mrow><mrow><msup><mrow><mi>q</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></msub></math></span>.</div><div>A number of analogous maximality results are discussed.</div></div>","PeriodicalId":50446,"journal":{"name":"Finite Fields and Their Applications","volume":"101 ","pages":"Article 102521"},"PeriodicalIF":1.2,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-23DOI: 10.1016/j.ffa.2024.102522
Sha Jiang, Mu Yuan, Kangquan Li, Longjiang Qu
<div><div>Permutation polynomials over finite fields are widely used in cryptography, coding theory, and combinatorial design. Particularly, permutation polynomials of the form <span><math><mi>x</mi><mo>+</mo><mi>γ</mi><msubsup><mrow><mi>Tr</mi></mrow><mrow><mi>q</mi></mrow><mrow><msup><mrow><mi>q</mi></mrow><mrow><mi>n</mi></mrow></msup></mrow></msubsup><mo>(</mo><mi>h</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo>)</mo></math></span> have been studied by many researchers and applied to lift minimal blocking sets. In this paper, we further investigate permutation polynomials of the form <span><math><mi>x</mi><mo>+</mo><mi>γ</mi><msubsup><mrow><mi>Tr</mi></mrow><mrow><mi>q</mi></mrow><mrow><msup><mrow><mi>q</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></msubsup><mo>(</mo><mi>h</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo>)</mo></math></span> over finite fields with even characteristic. On the one hand, guided by the idea of choosing functions <em>h</em> with a low <em>q</em>-degree, we completely determine the sufficient and necessary conditions of <em>γ</em> for six classes of polynomials of the form <span><math><mi>x</mi><mo>+</mo><mi>γ</mi><msubsup><mrow><mi>Tr</mi></mrow><mrow><mi>q</mi></mrow><mrow><msup><mrow><mi>q</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></msubsup><mo>(</mo><mi>h</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo>)</mo></math></span> with <span><math><mi>h</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo>=</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>1</mn></mrow></msub><mi>x</mi><mo>+</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>3</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>3</mn></mrow></msup><mo>+</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>4</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mi>q</mi><mo>+</mo><mn>2</mn></mrow></msup></math></span> and <span><math><msub><mrow><mi>c</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>∈</mo><msub><mrow><mi>F</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> (<span><math><mi>i</mi><mo>=</mo><mn>1</mn><mo>,</mo><mo>…</mo><mo>,</mo><mn>4</mn></math></span>) to be permutations. These results determine the sizes of directions of these six functions, which is generally difficult. On the other hand, we slightly generalize the above idea and construct other six classes of permutation polynomials of the form <span><math><mi>x</mi><mo>+</mo><mi>γ</mi><msubsup><mrow><mi>Tr</mi></mrow><mrow><mi>q</mi></mrow><mrow><msup><mrow><mi>q</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></msubsup><mo>(</mo><mi>h</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo>)</mo></math></span> with <span><math><mi>h</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo>=</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>1</mn></mrow></msub><mi>x</mi><mo>+</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>3</mn><
{"title":"New constructions of permutation polynomials of the form x+γTrqq2(h(x)) over finite fields with even characteristic","authors":"Sha Jiang, Mu Yuan, Kangquan Li, Longjiang Qu","doi":"10.1016/j.ffa.2024.102522","DOIUrl":"10.1016/j.ffa.2024.102522","url":null,"abstract":"<div><div>Permutation polynomials over finite fields are widely used in cryptography, coding theory, and combinatorial design. Particularly, permutation polynomials of the form <span><math><mi>x</mi><mo>+</mo><mi>γ</mi><msubsup><mrow><mi>Tr</mi></mrow><mrow><mi>q</mi></mrow><mrow><msup><mrow><mi>q</mi></mrow><mrow><mi>n</mi></mrow></msup></mrow></msubsup><mo>(</mo><mi>h</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo>)</mo></math></span> have been studied by many researchers and applied to lift minimal blocking sets. In this paper, we further investigate permutation polynomials of the form <span><math><mi>x</mi><mo>+</mo><mi>γ</mi><msubsup><mrow><mi>Tr</mi></mrow><mrow><mi>q</mi></mrow><mrow><msup><mrow><mi>q</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></msubsup><mo>(</mo><mi>h</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo>)</mo></math></span> over finite fields with even characteristic. On the one hand, guided by the idea of choosing functions <em>h</em> with a low <em>q</em>-degree, we completely determine the sufficient and necessary conditions of <em>γ</em> for six classes of polynomials of the form <span><math><mi>x</mi><mo>+</mo><mi>γ</mi><msubsup><mrow><mi>Tr</mi></mrow><mrow><mi>q</mi></mrow><mrow><msup><mrow><mi>q</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></msubsup><mo>(</mo><mi>h</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo>)</mo></math></span> with <span><math><mi>h</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo>=</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>1</mn></mrow></msub><mi>x</mi><mo>+</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>3</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>3</mn></mrow></msup><mo>+</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>4</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mi>q</mi><mo>+</mo><mn>2</mn></mrow></msup></math></span> and <span><math><msub><mrow><mi>c</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>∈</mo><msub><mrow><mi>F</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> (<span><math><mi>i</mi><mo>=</mo><mn>1</mn><mo>,</mo><mo>…</mo><mo>,</mo><mn>4</mn></math></span>) to be permutations. These results determine the sizes of directions of these six functions, which is generally difficult. On the other hand, we slightly generalize the above idea and construct other six classes of permutation polynomials of the form <span><math><mi>x</mi><mo>+</mo><mi>γ</mi><msubsup><mrow><mi>Tr</mi></mrow><mrow><mi>q</mi></mrow><mrow><msup><mrow><mi>q</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></msubsup><mo>(</mo><mi>h</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo>)</mo></math></span> with <span><math><mi>h</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo>=</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>1</mn></mrow></msub><mi>x</mi><mo>+</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>3</mn><","PeriodicalId":50446,"journal":{"name":"Finite Fields and Their Applications","volume":"101 ","pages":"Article 102522"},"PeriodicalIF":1.2,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-23DOI: 10.1016/j.ffa.2024.102525
Darien Connolly , Calvin George , Xiang-dong Hou , Adam Madro , Vincenzo Pallozzi Lavorante
An irreducible polynomial of degree n is normal over if and only if its roots satisfy the condition , where is the circulant determinant. By finding a suitable symmetrization of (A multiple of which is symmetric in ), we obtain a condition on the coefficients of f that is sufficient for f to be normal. This approach works well for but encounters computational difficulties when . In the present paper, we consider irreducible polynomials of the form . For and 7, by an indirect method, we are able to find simple conditions on a that are sufficient for f to be normal. In a more general context, we also explore the normal polynomials of a finite Galois extension through the irreducible characters of the Galois group.
当且仅当一个阶数为 n 的不可减多项式 f∈Fq[X] 的根 r,rq,...,rqn-1满足条件 Δn(r,rq,...,rqn-1)≠0,其中 Δn(X0,...,Xn-1)是 n×n 循环行列式时,这个 f∈Fq[X] 在 Fq 上是正常的。通过找到 Δn 的合适对称性(在 X0,...,Xn-1 中对称的 Δn 的倍数),我们就能得到 f 的系数条件,该条件足以保证 f 是正态的。这种方法在 n≤5 时效果很好,但在 n≥6 时遇到了计算上的困难。在本文中,我们考虑 f=Xn+Xn-1+a∈Fq[X] 形式的不可约多项式。对于 n=6 和 7,通过间接方法,我们能够找到关于 a 的简单条件,这些条件足以使 f 成为正多边形。在更一般的情况下,我们还通过伽罗瓦群的不可还原字符来探索有限伽罗瓦扩展的正多项式。
{"title":"An approach to normal polynomials through symmetrization and symmetric reduction","authors":"Darien Connolly , Calvin George , Xiang-dong Hou , Adam Madro , Vincenzo Pallozzi Lavorante","doi":"10.1016/j.ffa.2024.102525","DOIUrl":"10.1016/j.ffa.2024.102525","url":null,"abstract":"<div><div>An irreducible polynomial <span><math><mi>f</mi><mo>∈</mo><msub><mrow><mi>F</mi></mrow><mrow><mi>q</mi></mrow></msub><mo>[</mo><mi>X</mi><mo>]</mo></math></span> of degree <em>n</em> is <em>normal</em> over <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>q</mi></mrow></msub></math></span> if and only if its roots <span><math><mi>r</mi><mo>,</mo><msup><mrow><mi>r</mi></mrow><mrow><mi>q</mi></mrow></msup><mo>,</mo><mo>…</mo><mo>,</mo><msup><mrow><mi>r</mi></mrow><mrow><msup><mrow><mi>q</mi></mrow><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow></msup></mrow></msup></math></span> satisfy the condition <span><math><msub><mrow><mi>Δ</mi></mrow><mrow><mi>n</mi></mrow></msub><mo>(</mo><mi>r</mi><mo>,</mo><msup><mrow><mi>r</mi></mrow><mrow><mi>q</mi></mrow></msup><mo>,</mo><mo>…</mo><mo>,</mo><msup><mrow><mi>r</mi></mrow><mrow><msup><mrow><mi>q</mi></mrow><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow></msup></mrow></msup><mo>)</mo><mo>≠</mo><mn>0</mn></math></span>, where <span><math><msub><mrow><mi>Δ</mi></mrow><mrow><mi>n</mi></mrow></msub><mo>(</mo><msub><mrow><mi>X</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>,</mo><mo>…</mo><mo>,</mo><msub><mrow><mi>X</mi></mrow><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow></msub><mo>)</mo></math></span> is the <span><math><mi>n</mi><mo>×</mo><mi>n</mi></math></span> circulant determinant. By finding a suitable <em>symmetrization</em> of <span><math><msub><mrow><mi>Δ</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span> (A multiple of <span><math><msub><mrow><mi>Δ</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span> which is symmetric in <span><math><msub><mrow><mi>X</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>,</mo><mo>…</mo><mo>,</mo><msub><mrow><mi>X</mi></mrow><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow></msub></math></span>), we obtain a condition on the coefficients of <em>f</em> that is sufficient for <em>f</em> to be normal. This approach works well for <span><math><mi>n</mi><mo>≤</mo><mn>5</mn></math></span> but encounters computational difficulties when <span><math><mi>n</mi><mo>≥</mo><mn>6</mn></math></span>. In the present paper, we consider irreducible polynomials of the form <span><math><mi>f</mi><mo>=</mo><msup><mrow><mi>X</mi></mrow><mrow><mi>n</mi></mrow></msup><mo>+</mo><msup><mrow><mi>X</mi></mrow><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow></msup><mo>+</mo><mi>a</mi><mo>∈</mo><msub><mrow><mi>F</mi></mrow><mrow><mi>q</mi></mrow></msub><mo>[</mo><mi>X</mi><mo>]</mo></math></span>. For <span><math><mi>n</mi><mo>=</mo><mn>6</mn></math></span> and 7, by an indirect method, we are able to find simple conditions on <em>a</em> that are sufficient for <em>f</em> to be normal. In a more general context, we also explore the normal polynomials of a finite Galois extension through the irreducible characters of the Galois group.</div></div>","PeriodicalId":50446,"journal":{"name":"Finite Fields and Their Applications","volume":"101 ","pages":"Article 102525"},"PeriodicalIF":1.2,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-21DOI: 10.1016/j.ffa.2024.102523
Danyao Wu , Pingzhi Yuan , Huanhuan Guan , Juan Li
R. Gupta, P. Gahlyan and R.K. Sharma presented three classes of permutation trinomials over in Finite Fields and Their Applications. In this paper, we employ the local method to prove that those polynomials are indeed permutation polynomials and provide their compositional inverses.
{"title":"The compositional inverses of three classes of permutation polynomials over finite fields","authors":"Danyao Wu , Pingzhi Yuan , Huanhuan Guan , Juan Li","doi":"10.1016/j.ffa.2024.102523","DOIUrl":"10.1016/j.ffa.2024.102523","url":null,"abstract":"<div><div>R. Gupta, P. Gahlyan and R.K. Sharma presented three classes of permutation trinomials over <span><math><msub><mrow><mi>F</mi></mrow><mrow><msup><mrow><mi>q</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></msub></math></span> in Finite Fields and Their Applications. In this paper, we employ the local method to prove that those polynomials are indeed permutation polynomials and provide their compositional inverses.</div></div>","PeriodicalId":50446,"journal":{"name":"Finite Fields and Their Applications","volume":"101 ","pages":"Article 102523"},"PeriodicalIF":1.2,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.ffa.2024.102520
Arthur Fernandes , Daniel Panario , Lucas Reis
In this paper, we study stable binomials over finite fields, i.e., irreducible binomials such that all their iterates are also irreducible over . We obtain a simple criterion on the stability of binomials based on the forward orbit of 0 under the map . In particular, our criterion extends the one obtained by Jones and Boston (2011) for the quadratic case. As applications of our main result, we obtain an explicit 1-parameter family of stable quartics over prime fields with and also develop an algorithm to test the stability of binomials over finite fields. Finally, building upon a work of Ostafe and Shparlinski (2010), we employ character sums to bound the complexity of such algorithm.
{"title":"Stable binomials over finite fields","authors":"Arthur Fernandes , Daniel Panario , Lucas Reis","doi":"10.1016/j.ffa.2024.102520","DOIUrl":"10.1016/j.ffa.2024.102520","url":null,"abstract":"<div><div>In this paper, we study stable binomials over finite fields, i.e., irreducible binomials <span><math><msup><mrow><mi>x</mi></mrow><mrow><mi>t</mi></mrow></msup><mo>−</mo><mi>b</mi><mo>∈</mo><msub><mrow><mi>F</mi></mrow><mrow><mi>q</mi></mrow></msub><mo>[</mo><mi>x</mi><mo>]</mo></math></span> such that all their iterates are also irreducible over <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>q</mi></mrow></msub></math></span>. We obtain a simple criterion on the stability of binomials based on the forward orbit of 0 under the map <span><math><mi>z</mi><mo>↦</mo><msup><mrow><mi>z</mi></mrow><mrow><mi>t</mi></mrow></msup><mo>−</mo><mi>b</mi></math></span>. In particular, our criterion extends the one obtained by Jones and Boston (2011) for the quadratic case. As applications of our main result, we obtain an explicit 1-parameter family of stable quartics over prime fields <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> with <span><math><mi>p</mi><mo>≡</mo><mn>5</mn><mspace></mspace><mo>(</mo><mrow><mi>mod</mi></mrow><mspace></mspace><mn>24</mn><mo>)</mo></math></span> and also develop an algorithm to test the stability of binomials over finite fields. Finally, building upon a work of Ostafe and Shparlinski (2010), we employ character sums to bound the complexity of such algorithm.</div></div>","PeriodicalId":50446,"journal":{"name":"Finite Fields and Their Applications","volume":"101 ","pages":"Article 102520"},"PeriodicalIF":1.2,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}