Pub Date : 2024-01-29DOI: 10.1017/s0004972723001454
RENRONG MAO
Ranks of partitions play an important role in the theory of partitions. They provide combinatorial interpretations for Ramanujan’s famous congruences for partition functions. We establish a family of congruences modulo powers of $5$ for ranks of partitions.
{"title":"CONGRUENCES FOR RANKS OF PARTITIONS","authors":"RENRONG MAO","doi":"10.1017/s0004972723001454","DOIUrl":"https://doi.org/10.1017/s0004972723001454","url":null,"abstract":"Ranks of partitions play an important role in the theory of partitions. They provide combinatorial interpretations for Ramanujan’s famous congruences for partition functions. We establish a family of congruences modulo powers of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001454_inline1.png\" /> <jats:tex-math> $5$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> for ranks of partitions.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139586215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-29DOI: 10.1017/s0004972723001363
NADIA TAGHIPOUR, SHAMILA BAYATI, FARHAD RAHMATI
It is well known that the edge ideal $I(G)$ of a simple graph G has linear quotients if and only if $G^c$ is chordal. We investigate when the property of having linear quotients is inherited by homological shift ideals of an edge ideal. We will see that adding a cluster to the graph $G^c$ when $I(G)$ has homological linear quotients results in a graph with the same property. In particular, $I(G)$ has homological linear quotients when $G^c$ is a block graph. We also show that adding pinnacles to trees preserves the property of having homological linear quotients for the edge ideal of their complements. Furthermore, $I(G)$ has homological linear quotients for every graph G such that $G^c$ is a $lambda $ -min
{"title":"HOMOLOGICAL LINEAR QUOTIENTS AND EDGE IDEALS OF GRAPHS","authors":"NADIA TAGHIPOUR, SHAMILA BAYATI, FARHAD RAHMATI","doi":"10.1017/s0004972723001363","DOIUrl":"https://doi.org/10.1017/s0004972723001363","url":null,"abstract":"It is well known that the edge ideal <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001363_inline1.png\" /> <jats:tex-math> $I(G)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> of a simple graph <jats:italic>G</jats:italic> has linear quotients if and only if <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001363_inline2.png\" /> <jats:tex-math> $G^c$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is chordal. We investigate when the property of having linear quotients is inherited by homological shift ideals of an edge ideal. We will see that adding a cluster to the graph <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001363_inline3.png\" /> <jats:tex-math> $G^c$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> when <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001363_inline4.png\" /> <jats:tex-math> $I(G)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> has homological linear quotients results in a graph with the same property. In particular, <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001363_inline5.png\" /> <jats:tex-math> $I(G)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> has homological linear quotients when <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001363_inline6.png\" /> <jats:tex-math> $G^c$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is a block graph. We also show that adding pinnacles to trees preserves the property of having homological linear quotients for the edge ideal of their complements. Furthermore, <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001363_inline7.png\" /> <jats:tex-math> $I(G)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> has homological linear quotients for every graph <jats:italic>G</jats:italic> such that <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001363_inline8.png\" /> <jats:tex-math> $G^c$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is a <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001363_inline9.png\" /> <jats:tex-math> $lambda $ </jats:tex-math> </jats:alternatives> </jats:inline-formula>-min","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139586223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-29DOI: 10.1017/s0004972723001375
SUZANA MENDES-GONÇALVES, R. P. SULLIVAN
Brazil et al. [‘Maximal subgroups of infinite symmetric groups’, Proc. Lond. Math. Soc. (3)68(1) (1994), 77–111] provided a new family of maximal subgroups of the symmetric group $G(X)$ defined on an infinite set X. It is easy to see that, in this case, $G(X)$ contains subsemigroups that are not groups, but nothing is known about nongroup maximal subsemigroups of $G(X)$ . We provide infinitely many examples of such semigroups.
Brazil et al. ['Maximal subgroups of infinite symmetric groups', Proc.Lond.Math.(3)68(1) (1994), 77-111] 提供了定义在无限集 X 上的对称群 $G(X)$ 的最大子群的新族。我们提供了无限多此类半群的例子。
{"title":"MAXIMAL SUBSEMIGROUPS OF INFINITE SYMMETRIC GROUPS","authors":"SUZANA MENDES-GONÇALVES, R. P. SULLIVAN","doi":"10.1017/s0004972723001375","DOIUrl":"https://doi.org/10.1017/s0004972723001375","url":null,"abstract":"Brazil <jats:italic>et al</jats:italic>. [‘Maximal subgroups of infinite symmetric groups’, <jats:italic>Proc. Lond. Math. Soc. (3)</jats:italic>68(1) (1994), 77–111] provided a new family of maximal subgroups of the symmetric group <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001375_inline1.png\" /> <jats:tex-math> $G(X)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> defined on an infinite set <jats:italic>X</jats:italic>. It is easy to see that, in this case, <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001375_inline2.png\" /> <jats:tex-math> $G(X)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> contains subsemigroups that are not groups, but nothing is known about nongroup maximal subsemigroups of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001375_inline3.png\" /> <jats:tex-math> $G(X)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. We provide infinitely many examples of such semigroups.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139586222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-26DOI: 10.1017/s0004972723001429
MALLORY DOLORFINO, LUKE MARTIN, ZACHARY SLONIM, YUXUAN SUN, YONG YANG
Let G be a finite group and $mathrm {Irr}(G)$ the set of all irreducible complex characters of G. Define the codegree of $chi in mathrm {Irr}(G)$ as $mathrm {cod}(chi ):={|G:mathrm {ker}(chi ) |}/{chi (1)}$ and let $mathrm {cod}(G):={mathrm {cod}(chi ) mid chi in mathrm {Irr}(G)}$ be the codegree set of G. Let $mathrm {A}_n$ be an alternating group of degree $n ge 5$ . We show that $mathrm {A}_n$ is determined up to isomorphism by $operatorname {cod}(mathrm {A}_n)$ .
让 G 是一个有限群,$mathrm {Irrr}(G)$ 是 G 所有不可还原复字符的集合。定义 $chi 在 mathrm {Irr}(G)$ 中的codegree为 $mathrm {cod}(chi ):={|G:|}/{chi (1)}$ 并且让 $mathrm {cod}(G):={mathrm {cod}(chi ) mid chi in mathrm {Irrr}(G)}$ 是 G 的codegree集合。让 $mathrm {A}_n$ 是一个度数为 $nge 5$ 的交替群。我们证明 $mathrm {A}_n$ 是由 $operatorname {cod}(mathrm {A}_n)$ 同构决定的。
{"title":"ON THE CHARACTERISATION OF ALTERNATING GROUPS BY CODEGREES","authors":"MALLORY DOLORFINO, LUKE MARTIN, ZACHARY SLONIM, YUXUAN SUN, YONG YANG","doi":"10.1017/s0004972723001429","DOIUrl":"https://doi.org/10.1017/s0004972723001429","url":null,"abstract":"Let <jats:italic>G</jats:italic> be a finite group and <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline1.png\" /> <jats:tex-math> $mathrm {Irr}(G)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> the set of all irreducible complex characters of <jats:italic>G</jats:italic>. Define the codegree of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline2.png\" /> <jats:tex-math> $chi in mathrm {Irr}(G)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> as <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline3.png\" /> <jats:tex-math> $mathrm {cod}(chi ):={|G:mathrm {ker}(chi ) |}/{chi (1)}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> and let <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline4.png\" /> <jats:tex-math> $mathrm {cod}(G):={mathrm {cod}(chi ) mid chi in mathrm {Irr}(G)}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> be the codegree set of <jats:italic>G</jats:italic>. Let <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline5.png\" /> <jats:tex-math> $mathrm {A}_n$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> be an alternating group of degree <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline6.png\" /> <jats:tex-math> $n ge 5$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. We show that <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline7.png\" /> <jats:tex-math> $mathrm {A}_n$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is determined up to isomorphism by <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline8.png\" /> <jats:tex-math> $operatorname {cod}(mathrm {A}_n)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139586153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-26DOI: 10.1017/s0004972723001442
MARTIN R. BRIDSON, HAMISH SHORT
Every countable group G can be embedded in a finitely generated group $G^*$ that is hopfian and complete, that is, $G^*$ has trivial centre and every epimorphism $G^*to G^*$ is an inner automorphism. Every finite subgroup of $G^*$ is conjugate to a finite subgroup of G. If G has a finite presentation (respectively, a finite classifying space), then so does $G^*$ . Our construction of $G^*$ relies on the existence of closed hyperbolic 3-manifolds that are asymmetric and non-Haken.
每个可数群 G 都可以嵌入一个有限生成的群 $G^*$,而这个群是跳化的和完全的,也就是说,$G^*$ 有微不足道的中心,并且每个外变 $G^*to G^*$ 都是一个内自变。$G^*$ 的每个有限子群都与 G 的一个有限子群共轭。如果 G 有一个有限的呈现(分别是有限的分类空间),那么 $G^*$ 也是如此。我们对 $G^*$ 的构造依赖于非对称和非哈肯的封闭双曲 3-manifolds。
{"title":"COMPLETE EMBEDDINGS OF GROUPS","authors":"MARTIN R. BRIDSON, HAMISH SHORT","doi":"10.1017/s0004972723001442","DOIUrl":"https://doi.org/10.1017/s0004972723001442","url":null,"abstract":"Every countable group <jats:italic>G</jats:italic> can be embedded in a finitely generated group <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001442_inline1.png\" /> <jats:tex-math> $G^*$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> that is hopfian and <jats:italic>complete</jats:italic>, that is, <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001442_inline2.png\" /> <jats:tex-math> $G^*$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> has trivial centre and every epimorphism <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001442_inline3.png\" /> <jats:tex-math> $G^*to G^*$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is an inner automorphism. Every finite subgroup of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001442_inline4.png\" /> <jats:tex-math> $G^*$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is conjugate to a finite subgroup of <jats:italic>G</jats:italic>. If <jats:italic>G</jats:italic> has a finite presentation (respectively, a finite classifying space), then so does <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001442_inline5.png\" /> <jats:tex-math> $G^*$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. Our construction of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001442_inline6.png\" /> <jats:tex-math> $G^*$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> relies on the existence of closed hyperbolic 3-manifolds that are asymmetric and non-Haken.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139586224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-26DOI: 10.1017/s0004972723001399
PABLO BHOWMIK, FIRDAVS RAKHMONOV
Let $mathbb {F}_q^d$ denote the d-dimensional vector space over the finite field $mathbb {F}_q$ with q elements. Define for $alpha = (alpha _1, dots , alpha _d) in mathbb {F}_q^d$ . Let $kin mathbb {N}$ , A be a nonempty subset of ${(i, j): 1 leq i < j leq k + 1}$ and $rin (mathbb {F}_q)^2setminus {0}$ , where $(mathbb {F}_q)^2={a^2:ain mathbb {F}_q}$ . If $Esubset mathbb {F}_q^d$ , our main result demonstrates that when the size of the set E satisfies $|E| geq C_k q^{d/2}$ , where
让 $mathbb {F}_q^d$ 表示有限域 $mathbb {F}_q$ 上有 q 个元素的 d 维向量空间。在 mathbb {F}_q^d$ 中定义 $alpha = (alpha _1, dots , alpha _d) 。让 $kin mathbb {N}$ , A 是 ${(i, j) 的一个非空子集:1 leq i < j leq k + 1}$ 和 $rin (mathbb {F}_q)^2setminus {0}$ , 其中 $(mathbb {F}_q)^2={a^2:a in mathbb {F}_q}$ .如果 $Esubset mathbb {F}_q^d$ ,我们的主要结果表明,当集合 E 的大小满足 $|E| geq C_k q^{d/2}$ 时,其中 $C_k$ 是一个完全取决于 k 的常数,那么就有可能在 E 中找到两个 $(k+1)$ 图元,使得其中一个图元相对于另一个图元扩张了 r,但只沿着 $|A|$ 边。更准确地说,我们确定在 E^{k+1}$ 中存在 $(x_1, dots , x_{k+1}) ,在 E^{k+1}$ 中存在 $(y_1, dots , y_{k+1}) ,这样,对于 $(i, j) in A$ 、我们有 $lVert y_i - y_j rVert = r lVert x_i - x_j rVert $ ,条件是 $x_i neq x_j$ 和 $y_i neq y_j$ for $1 leq i <;j leq k + 1$ 条件是 $|E| geq C_k q^{d/2}$ 和 $rin (mathbb {F}_q)^2setminus {0}$ 。我们为这一结果提供了两个不同的证明。第一个证明使用了群作用技术,这是解决此类问题的一种强有力的方法;第二个证明则基于基本的组合推理。此外,我们还证明了在维度 2 中,当 $q equiv 3 pmod 4$ 时,阈值 $d/2$ 是尖锐的。作为主要结果的推论,通过改变底层集合 A,我们确定了扩张 k 循环、k 路径和 k 星(其中 $k geq 3$ )存在的阈值,其扩张比为 $rin (mathbb {F}_q)^2setminus {0}$ 。这些结果改进并概括了 Xie 和 Ge 的发现['Some results on similar configurations in subsets of $mathbb {F}_q^d$ ', Finite Fields Appl.91 (2023), Article no.102252, 20 pages].
{"title":"NEAR OPTIMAL THRESHOLDS FOR EXISTENCE OF DILATED CONFIGURATIONS IN","authors":"PABLO BHOWMIK, FIRDAVS RAKHMONOV","doi":"10.1017/s0004972723001399","DOIUrl":"https://doi.org/10.1017/s0004972723001399","url":null,"abstract":"Let <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001399_inline2.png\" /> <jats:tex-math> $mathbb {F}_q^d$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> denote the <jats:italic>d</jats:italic>-dimensional vector space over the finite field <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001399_inline3.png\" /> <jats:tex-math> $mathbb {F}_q$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> with <jats:italic>q</jats:italic> elements. Define <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001399_inline4.png\" /> for <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001399_inline5.png\" /> <jats:tex-math> $alpha = (alpha _1, dots , alpha _d) in mathbb {F}_q^d$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. Let <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001399_inline6.png\" /> <jats:tex-math> $kin mathbb {N}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, <jats:italic>A</jats:italic> be a nonempty subset of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001399_inline7.png\" /> <jats:tex-math> ${(i, j): 1 leq i < j leq k + 1}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> and <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001399_inline8.png\" /> <jats:tex-math> $rin (mathbb {F}_q)^2setminus {0}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, where <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001399_inline9.png\" /> <jats:tex-math> $(mathbb {F}_q)^2={a^2:ain mathbb {F}_q}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. If <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001399_inline10.png\" /> <jats:tex-math> $Esubset mathbb {F}_q^d$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, our main result demonstrates that when the size of the set <jats:italic>E</jats:italic> satisfies <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001399_inline11.png\" /> <jats:tex-math> $|E| geq C_k q^{d/2}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, where <jats:inline-formula> <jats:alternatives> <ja","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139589880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-10DOI: 10.1017/s0004972723001338
ANDRÉS CHIRRE
We provide explicit bounds for the Riemann zeta-function on the line $mathrm {Re},{s}=1$, assuming that the Riemann hypothesis holds up to height T. In particular, we improve some bounds in finite regions for the logarithmic derivative and the reciprocal of the Riemann zeta-function.
我们为直线 $mathrm {Re},{s}=1$ 上的黎曼zeta函数提供了明确的边界,假定黎曼假设在高度 T 上成立。特别是,我们改进了黎曼zeta函数的对数导数和倒数在有限区域内的一些边界。
{"title":"BOUNDING ZETA ON THE 1-LINE UNDER THE PARTIAL RIEMANN HYPOTHESIS","authors":"ANDRÉS CHIRRE","doi":"10.1017/s0004972723001338","DOIUrl":"https://doi.org/10.1017/s0004972723001338","url":null,"abstract":"<p>We provide explicit bounds for the Riemann zeta-function on the line <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240109124905552-0701:S0004972723001338:S0004972723001338_inline1.png\"><span data-mathjax-type=\"texmath\"><span>$mathrm {Re},{s}=1$</span></span></img></span></span>, assuming that the Riemann hypothesis holds up to height <span>T</span>. In particular, we improve some bounds in finite regions for the logarithmic derivative and the reciprocal of the Riemann zeta-function.</p>","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139414794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-27DOI: 10.1017/s0004972723001326
KEVIN BEANLAND, DMITRIY GOROVOY, JĘDRZEJ HODOR, DANIIL HOMZA
A subset of positive integers F is a Schreier set if it is nonempty and $|F|leqslant min F$ (here $|F|$ is the cardinality of F). For each positive integer k, we define $kmathcal {S}$ as the collection of all the unions of at most k Schreier sets. Also, for each positive integer n, let $(kmathcal {S})^n$ be the collection of all sets in $kmathcal {S}$ with maximum element equal to n. It is well known that the sequence $(|(1mathcal {S})^n|)_{n=1}^infty $ is the Fibonacci sequence. In particular, the sequence satisfies a linear recurrence. We show that the sequence $(|(kmathcal {S})^n|)_{n=1}^infty $ satisfies a linear recurrence for every positive k.
如果一个正整数子集 F 是非空的,并且 $|F|leqslant min F$(这里 $|F|$ 是 F 的万有引力),那么它就是施赖耶集。对于每个正整数 k,我们定义 $kmathcal {S}$ 为最多 k 个施赖尔集合的所有联合的集合。另外,对于每个正整数 n,让 $(kmathcal {S})^n$ 成为 $kmathcal {S}$ 中最大元素等于 n 的所有集合的集合。众所周知,序列 $(|(1mathcal {S})^n|)_{n=1}^infty $ 就是斐波那契序列。特别是,该序列满足线性递推。我们证明了序列 $(|(kmathcal {S})^n|)_{n=1}^infty $ 满足每一个正 k 的线性递归。
{"title":"COUNTING UNIONS OF SCHREIER SETS","authors":"KEVIN BEANLAND, DMITRIY GOROVOY, JĘDRZEJ HODOR, DANIIL HOMZA","doi":"10.1017/s0004972723001326","DOIUrl":"https://doi.org/10.1017/s0004972723001326","url":null,"abstract":"A subset of positive integers <jats:italic>F</jats:italic> is a Schreier set if it is nonempty and <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001326_inline1.png\" /> <jats:tex-math> $|F|leqslant min F$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> (here <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001326_inline2.png\" /> <jats:tex-math> $|F|$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is the cardinality of <jats:italic>F</jats:italic>). For each positive integer <jats:italic>k</jats:italic>, we define <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001326_inline3.png\" /> <jats:tex-math> $kmathcal {S}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> as the collection of all the unions of at most <jats:italic>k</jats:italic> Schreier sets. Also, for each positive integer <jats:italic>n</jats:italic>, let <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001326_inline4.png\" /> <jats:tex-math> $(kmathcal {S})^n$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> be the collection of all sets in <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001326_inline5.png\" /> <jats:tex-math> $kmathcal {S}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> with maximum element equal to <jats:italic>n</jats:italic>. It is well known that the sequence <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001326_inline6.png\" /> <jats:tex-math> $(|(1mathcal {S})^n|)_{n=1}^infty $ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is the Fibonacci sequence. In particular, the sequence satisfies a linear recurrence. We show that the sequence <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001326_inline7.png\" /> <jats:tex-math> $(|(kmathcal {S})^n|)_{n=1}^infty $ </jats:tex-math> </jats:alternatives> </jats:inline-formula> satisfies a linear recurrence for every positive <jats:italic>k</jats:italic>.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139052831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-27DOI: 10.1017/s0004972723001168
LIJUAN HE, HENG LV, GUIYUN CHEN
Suppose that G is a finite solvable group. Let $t=n_c(G)$ denote the number of orders of nonnormal subgroups of G. We bound the derived length $dl(G)$ in terms of $n_c(G)$ . If G is a finite p-group, we show that $|G'|leq p^{2t+1}$ and $dl(G)leq lceil log _2(2t+3)rceil $ . If G is a finite solvable nonnilpotent group, we prove that the sum of the powers of the prime divisors of $|G'|$ is less than t and that $dl(G)leq lfloor 2(t+1)/3rfloor +1$ .
假设 G 是一个有限可解群。让 $t=n_c(G)$ 表示 G 的非正则子群的阶数。我们用 $n_c(G)$ 约束派生长度 $dl(G)$ 。如果 G 是有限 p 群,我们证明 $|G'|leq p^{2t+1}$ 和 $dl(G)leq lceil log _2(2t+3)rceil $ 。如果 G 是一个有限可解的非幂群,我们证明 $|G'|$ 的素除数的幂和小于 t 并且 $dl(G)leq lfloor 2(t+1)/3rfloor +1$ .
{"title":"SOLVABLE GROUPS WHOSE NONNORMAL SUBGROUPS HAVE FEW ORDERS","authors":"LIJUAN HE, HENG LV, GUIYUN CHEN","doi":"10.1017/s0004972723001168","DOIUrl":"https://doi.org/10.1017/s0004972723001168","url":null,"abstract":"Suppose that <jats:italic>G</jats:italic> is a finite solvable group. Let <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001168_inline1.png\" /> <jats:tex-math> $t=n_c(G)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> denote the number of orders of nonnormal subgroups of <jats:italic>G</jats:italic>. We bound the derived length <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001168_inline2.png\" /> <jats:tex-math> $dl(G)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> in terms of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001168_inline3.png\" /> <jats:tex-math> $n_c(G)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. If <jats:italic>G</jats:italic> is a finite <jats:italic>p</jats:italic>-group, we show that <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001168_inline4.png\" /> <jats:tex-math> $|G'|leq p^{2t+1}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> and <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001168_inline5.png\" /> <jats:tex-math> $dl(G)leq lceil log _2(2t+3)rceil $ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. If <jats:italic>G</jats:italic> is a finite solvable nonnilpotent group, we prove that the sum of the powers of the prime divisors of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001168_inline6.png\" /> <jats:tex-math> $|G'|$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is less than <jats:italic>t</jats:italic> and that <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001168_inline7.png\" /> <jats:tex-math> $dl(G)leq lfloor 2(t+1)/3rfloor +1$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139052909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-27DOI: 10.1017/s000497272300134x
NATALIA GARCIA-FRITZ, HECTOR PASTEN
Bogomolov and Tschinkel [‘Algebraic varieties over small fields’, Diophantine Geometry, U. Zannier (ed.), CRM Series, 4 (Scuola Normale Superiore di Pisa, Pisa, 2007), 73–91] proved that, given two complex elliptic curves $E_1$ and $E_2$ along with even degree- $2$ maps $pi _jcolon E_jto mathbb {P}^1$ having different branch loci, the intersection of the image of the torsion points of $E_1$ and $E_2$ under their respective $pi _j$ is finite. They conjectured (also in works with Fu) that the cardinality of this intersection is uniformly bounded independently of the elliptic curves. The recent proof of the uniform Manin–Mumford conjecture implies a full solution of the Bogomolov–Fu–Tschinkel conjecture. In this paper, we prove a generalisation of the Bogomolov–Fu–Tschinkel conjecture whereby, instead of even degree- $2$ maps, one can use any rational functions of bounded degree on the elliptic curves as long as they have different branch loci. Our approach combines Nevanlinna th
{"title":"INTERSECTING THE TORSION OF ELLIPTIC CURVES","authors":"NATALIA GARCIA-FRITZ, HECTOR PASTEN","doi":"10.1017/s000497272300134x","DOIUrl":"https://doi.org/10.1017/s000497272300134x","url":null,"abstract":"Bogomolov and Tschinkel [‘Algebraic varieties over small fields’, <jats:italic>Diophantine Geometry</jats:italic>, U. Zannier (ed.), CRM Series, 4 (Scuola Normale Superiore di Pisa, Pisa, 2007), 73–91] proved that, given two complex elliptic curves <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272300134X_inline1.png\" /> <jats:tex-math> $E_1$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> and <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272300134X_inline2.png\" /> <jats:tex-math> $E_2$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> along with even degree-<jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272300134X_inline3.png\" /> <jats:tex-math> $2$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> maps <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272300134X_inline4.png\" /> <jats:tex-math> $pi _jcolon E_jto mathbb {P}^1$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> having different branch loci, the intersection of the image of the torsion points of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272300134X_inline5.png\" /> <jats:tex-math> $E_1$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> and <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272300134X_inline6.png\" /> <jats:tex-math> $E_2$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> under their respective <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272300134X_inline7.png\" /> <jats:tex-math> $pi _j$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is finite. They conjectured (also in works with Fu) that the cardinality of this intersection is uniformly bounded independently of the elliptic curves. The recent proof of the uniform Manin–Mumford conjecture implies a full solution of the Bogomolov–Fu–Tschinkel conjecture. In this paper, we prove a generalisation of the Bogomolov–Fu–Tschinkel conjecture whereby, instead of even degree-<jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272300134X_inline8.png\" /> <jats:tex-math> $2$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> maps, one can use any rational functions of bounded degree on the elliptic curves as long as they have different branch loci. Our approach combines Nevanlinna th","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139053000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}