Pub Date : 2024-09-23DOI: 10.1016/j.jnt.2024.09.001
Attila Pethő , Szabolcs Tengely
Let not all zeroes and let be the linear recursive sequence, which is defined by the initial terms and whose characteristic polynomial is Daniel Shanks simplest cubic . We prove that there exists an effectively computable constant c depending only on such that if holds for some integers with then . For the choices we solve the above equations completely. At the end we give an outlook to the equation for some fixed integers .
{"title":"Common values of linear recurrences related to Shank's simplest cubics","authors":"Attila Pethő , Szabolcs Tengely","doi":"10.1016/j.jnt.2024.09.001","DOIUrl":"10.1016/j.jnt.2024.09.001","url":null,"abstract":"<div><div>Let <span><math><mi>A</mi><mo>,</mo><mi>B</mi><mo>,</mo><mi>C</mi><mo>∈</mo><mi>Z</mi></math></span> not all zeroes and let <span><math><mi>F</mi><mo>(</mo><mi>u</mi><mo>,</mo><mi>n</mi><mo>)</mo><mo>=</mo><mi>F</mi><mo>(</mo><mi>A</mi><mo>,</mo><mi>B</mi><mo>,</mo><mi>C</mi><mo>,</mo><mi>u</mi><mo>,</mo><mi>n</mi><mo>)</mo></math></span> be the linear recursive sequence, which is defined by the initial terms <span><math><mi>F</mi><mo>(</mo><mi>u</mi><mo>,</mo><mn>0</mn><mo>)</mo><mo>=</mo><mi>A</mi><mo>,</mo><mi>F</mi><mo>(</mo><mi>u</mi><mo>,</mo><mn>1</mn><mo>)</mo><mo>=</mo><mi>B</mi><mo>,</mo><mi>F</mi><mo>(</mo><mi>u</mi><mo>,</mo><mn>2</mn><mo>)</mo><mo>=</mo><mi>C</mi></math></span> and whose characteristic polynomial is Daniel Shanks simplest cubic <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>u</mi></mrow></msub><mo>(</mo><mi>X</mi><mo>)</mo><mo>=</mo><msup><mrow><mi>X</mi></mrow><mrow><mn>3</mn></mrow></msup><mo>−</mo><mo>(</mo><mi>u</mi><mo>−</mo><mn>1</mn><mo>)</mo><msup><mrow><mi>X</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>−</mo><mo>(</mo><mi>u</mi><mo>+</mo><mn>2</mn><mo>)</mo><mi>X</mi><mo>−</mo><mn>1</mn><mo>,</mo><mi>u</mi><mo>∈</mo><mi>Z</mi></math></span>. We prove that there exists an effectively computable constant <em>c</em> depending only on <span><math><mi>L</mi><mo>=</mo><mi>max</mi><mo></mo><mo>{</mo><mo>|</mo><mi>A</mi><mo>|</mo><mo>,</mo><mo>|</mo><mi>B</mi><mo>|</mo><mo>,</mo><mo>|</mo><mi>C</mi><mo>|</mo><mo>}</mo></math></span> such that if <span><math><mo>|</mo><mi>F</mi><mo>(</mo><mi>A</mi><mo>,</mo><mi>B</mi><mo>,</mo><mi>C</mi><mo>,</mo><mi>u</mi><mo>,</mo><mi>n</mi><mo>)</mo><mo>|</mo><mo>=</mo><mo>|</mo><mi>F</mi><mo>(</mo><mi>A</mi><mo>,</mo><mi>B</mi><mo>,</mo><mi>C</mi><mo>,</mo><mi>u</mi><mo>,</mo><mi>m</mi><mo>)</mo><mo>|</mo></math></span> holds for some integers <span><math><mi>u</mi><mo>,</mo><mi>n</mi><mo>,</mo><mi>m</mi></math></span> with <span><math><mi>n</mi><mo>≠</mo><mi>m</mi></math></span> then <span><math><mo>|</mo><mi>n</mi><mo>|</mo><mo>,</mo><mo>|</mo><mi>m</mi><mo>|</mo><mo><</mo><mi>c</mi></math></span>. For the choices <span><math><mo>(</mo><mi>A</mi><mo>,</mo><mi>B</mi><mo>,</mo><mi>C</mi><mo>)</mo><mo>∈</mo><mo>{</mo><mo>(</mo><mn>0</mn><mo>,</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>)</mo><mo>,</mo><mo>(</mo><mn>1</mn><mo>,</mo><mo>−</mo><mn>1</mn><mo>,</mo><mn>1</mn><mo>)</mo><mo>}</mo></math></span> we solve the above equations completely. At the end we give an outlook to the equation <span><math><mi>F</mi><mo>(</mo><mn>0</mn><mo>,</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>,</mo><mi>u</mi><mo>,</mo><mi>n</mi><mo>)</mo><mo>=</mo><mi>F</mi><mo>(</mo><mn>0</mn><mo>,</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>,</mo><mi>v</mi><mo>,</mo><mi>m</mi><mo>)</mo></math></span> for some fixed integers <span><math><mi>n</mi><mo>,</mo><mi>m</mi></math></span>.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"267 ","pages":"Pages 34-79"},"PeriodicalIF":0.6,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328260","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 : 2024-09-23DOI: 10.1016/j.jnt.2024.08.007
Sourabhashis Das, Wentang Kuo, Yu-Ru Liu
Let k and n be natural numbers. Let denote the number of distinct prime factors of n with multiplicity k as studied by Elma and the third author [5]. We obtain asymptotic estimates for the first and the second moments of when restricted to the set of h-free and h-full numbers. We prove that has normal order over h-free numbers, has normal order over h-full numbers, and both of them satisfy the Erdős-Kac Theorem. Finally, we prove that the functions with do not have normal order over h-free numbers and with do not have normal order over h-full numbers.
设 k 和 n 都是自然数。让 ωk(n)表示乘数为 k 的 n 的不同质因数的个数,如 Elma 和第三作者所研究的那样[5]。我们得到了ωk(n)的第一矩和第二矩的渐近估计值,并将其限制在无 h 和满 h 的数集合中。我们证明ω1(n) 在 h 个无穷数上有正序 loglogn,ωh(n) 在 h 个满数上有正序 loglogn,而且它们都满足厄尔多斯-卡克定理。最后,我们证明含 1<k<h 的函数 ωk(n) 在无 h 数上没有正序,含 k>h 的函数 ωk(n) 在满 h 数上没有正序。
{"title":"On the number of prime factors with a given multiplicity over h-free and h-full numbers","authors":"Sourabhashis Das, Wentang Kuo, Yu-Ru Liu","doi":"10.1016/j.jnt.2024.08.007","DOIUrl":"10.1016/j.jnt.2024.08.007","url":null,"abstract":"<div><div>Let <em>k</em> and <em>n</em> be natural numbers. Let <span><math><msub><mrow><mi>ω</mi></mrow><mrow><mi>k</mi></mrow></msub><mo>(</mo><mi>n</mi><mo>)</mo></math></span> denote the number of distinct prime factors of <em>n</em> with multiplicity <em>k</em> as studied by Elma and the third author <span><span>[5]</span></span>. We obtain asymptotic estimates for the first and the second moments of <span><math><msub><mrow><mi>ω</mi></mrow><mrow><mi>k</mi></mrow></msub><mo>(</mo><mi>n</mi><mo>)</mo></math></span> when restricted to the set of <em>h</em>-free and <em>h</em>-full numbers. We prove that <span><math><msub><mrow><mi>ω</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>(</mo><mi>n</mi><mo>)</mo></math></span> has normal order <span><math><mi>log</mi><mo></mo><mi>log</mi><mo></mo><mi>n</mi></math></span> over <em>h</em>-free numbers, <span><math><msub><mrow><mi>ω</mi></mrow><mrow><mi>h</mi></mrow></msub><mo>(</mo><mi>n</mi><mo>)</mo></math></span> has normal order <span><math><mi>log</mi><mo></mo><mi>log</mi><mo></mo><mi>n</mi></math></span> over <em>h</em>-full numbers, and both of them satisfy the Erdős-Kac Theorem. Finally, we prove that the functions <span><math><msub><mrow><mi>ω</mi></mrow><mrow><mi>k</mi></mrow></msub><mo>(</mo><mi>n</mi><mo>)</mo></math></span> with <span><math><mn>1</mn><mo><</mo><mi>k</mi><mo><</mo><mi>h</mi></math></span> do not have normal order over <em>h</em>-free numbers and <span><math><msub><mrow><mi>ω</mi></mrow><mrow><mi>k</mi></mrow></msub><mo>(</mo><mi>n</mi><mo>)</mo></math></span> with <span><math><mi>k</mi><mo>></mo><mi>h</mi></math></span> do not have normal order over <em>h</em>-full numbers.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"267 ","pages":"Pages 176-201"},"PeriodicalIF":0.6,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328287","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 : 2024-09-23DOI: 10.1016/j.jnt.2024.08.003
Paul Pollack
Recall that for a domain R where every nonzero nonunit factors into irreducibles, the elasticity of R is defined as We call a quadratic field Kmaximally elastic if the ring of integers of K is a UFD and each element of appears as an elasticity of infinitely many orders inside K. This corresponds to the orders in K exhibiting, to the extent possible for a quadratic field, maximal variation in terms of the failure of unique factorization. Assuming the Generalized Riemann Hypothesis, we prove that is universally elastic, and we provide evidence for a conjectured characterization of maximally elastic quadratic fields.
回想一下,对于每个非零非单元都因数化为不可还原单元的域 R,R 的弹性定义如下{sr:π1⋯πr=ρ1⋯ρs,所有 πi,ρj 都不可还原}。如果 K 的整数环是 UFD,且{1,32,2,52,3,...}∪{∞}中的每个元素在 K 中作为无穷多阶的弹性出现,我们就称一个二次域 K 为最大弹性域。假设广义黎曼假说成立,我们证明 K=Q(2) 具有普遍弹性,并为最大弹性二次域的猜想特征提供证据。
{"title":"Maximally elastic quadratic fields","authors":"Paul Pollack","doi":"10.1016/j.jnt.2024.08.003","DOIUrl":"10.1016/j.jnt.2024.08.003","url":null,"abstract":"<div><div>Recall that for a domain <em>R</em> where every nonzero nonunit factors into irreducibles, the <span>elasticity</span> of <em>R</em> is defined as<span><span><span><math><mi>sup</mi><mo></mo><mrow><mo>{</mo><mfrac><mrow><mi>s</mi></mrow><mrow><mi>r</mi></mrow></mfrac><mo>:</mo><msub><mrow><mi>π</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>⋯</mo><msub><mrow><mi>π</mi></mrow><mrow><mi>r</mi></mrow></msub><mo>=</mo><msub><mrow><mi>ρ</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>⋯</mo><msub><mrow><mi>ρ</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>,</mo><mrow><mtext> with all </mtext><msub><mrow><mi>π</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>,</mo><msub><mrow><mi>ρ</mi></mrow><mrow><mi>j</mi></mrow></msub><mtext> irreducible</mtext></mrow><mo>}</mo></mrow><mo>.</mo></math></span></span></span> We call a quadratic field <em>K</em> <span>maximally elastic</span> if the ring of integers of <em>K</em> is a UFD and each element of <span><math><mo>{</mo><mn>1</mn><mo>,</mo><mfrac><mrow><mn>3</mn></mrow><mrow><mn>2</mn></mrow></mfrac><mo>,</mo><mn>2</mn><mo>,</mo><mfrac><mrow><mn>5</mn></mrow><mrow><mn>2</mn></mrow></mfrac><mo>,</mo><mn>3</mn><mo>,</mo><mo>…</mo><mo>}</mo><mo>∪</mo><mo>{</mo><mo>∞</mo><mo>}</mo></math></span> appears as an elasticity of infinitely many orders inside <em>K</em>. This corresponds to the orders in <em>K</em> exhibiting, to the extent possible for a quadratic field, maximal variation in terms of the failure of unique factorization. Assuming the Generalized Riemann Hypothesis, we prove that <span><math><mi>K</mi><mo>=</mo><mi>Q</mi><mo>(</mo><msqrt><mrow><mn>2</mn></mrow></msqrt><mo>)</mo></math></span> is universally elastic, and we provide evidence for a conjectured characterization of maximally elastic quadratic fields.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"267 ","pages":"Pages 80-100"},"PeriodicalIF":0.6,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328259","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 : 2024-09-23DOI: 10.1016/j.jnt.2024.08.005
Charles Wend-Waoga Tougma
A number field is a Pólya field when the module of integer-valued polynomials over its ring of integers has a regular basis. A quartic field is a -field when the Galois group of its splitting field is the dihedral group of 8 elements. In this paper, we prove that there are infinitely many -Pólya fields with ℓ ramified prime numbers for each and a Pólya field with ramified prime number, is, up to -isomorphism, , or a pure field. Consequently, we answer a question raised in [29] on -fields. The same question arises on pure fields. We find an upper bound for such fields. And for any integer ℓ less that this bound, we show that there are infinitely many pure Pólya fields with ℓ ramified prime numbers except when where we proved that there are only 2 fields (and their two conjugate fields)
{"title":"On dihedral Pólya fields","authors":"Charles Wend-Waoga Tougma","doi":"10.1016/j.jnt.2024.08.005","DOIUrl":"10.1016/j.jnt.2024.08.005","url":null,"abstract":"<div><div>A number field is a Pólya field when the module of integer-valued polynomials over its ring of integers has a regular basis. A quartic field is a <span><math><msub><mrow><mi>D</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span>-field when the Galois group of its splitting field is the dihedral group <span><math><msub><mrow><mi>D</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> of 8 elements. In this paper, we prove that there are infinitely many <span><math><msub><mrow><mi>D</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span>-Pólya fields with <em>ℓ</em> ramified prime numbers for each <span><math><mi>ℓ</mi><mo>∈</mo><mo>{</mo><mn>2</mn><mo>,</mo><mn>3</mn><mo>,</mo><mn>4</mn><mo>,</mo><mn>5</mn><mo>}</mo></math></span> and a <span><math><msub><mrow><mi>D</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> Pólya field with <span><math><mi>ℓ</mi><mo>=</mo><mn>1</mn></math></span> ramified prime number, is, up to <span><math><mi>Q</mi></math></span>-isomorphism, <span><math><mi>Q</mi><mrow><mo>(</mo><msqrt><mrow><mn>1</mn><mo>+</mo><msqrt><mrow><mn>2</mn></mrow></msqrt></mrow></msqrt><mo>)</mo></mrow></math></span>, <span><math><mi>Q</mi><mrow><mo>(</mo><msqrt><mrow><mo>−</mo><mn>1</mn><mo>+</mo><msqrt><mrow><mn>2</mn></mrow></msqrt></mrow></msqrt><mo>)</mo></mrow></math></span> or a pure field. Consequently, we answer a question raised in <span><span>[29]</span></span> on <span><math><msub><mrow><mi>D</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span>-fields. The same question arises on pure fields. We find an upper bound for such fields. And for any integer <em>ℓ</em> less that this bound, we show that there are infinitely many pure Pólya fields with <em>ℓ</em> ramified prime numbers except when <span><math><mi>ℓ</mi><mo>=</mo><mn>1</mn></math></span> where we proved that there are only 2 fields (and their two conjugate fields)</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"267 ","pages":"Pages 221-250"},"PeriodicalIF":0.6,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425074","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 : 2024-09-23DOI: 10.1016/j.jnt.2024.08.001
Eleni Agathocleous
We study an infinite family of j-invariant zero elliptic curves and their λ-isogenous curves , where D and are fundamental discriminants of a specific form, and λ is an isogeny of degree 3. A result of Honda guarantees that for our discriminants D, the quadratic number field always has non-trivial 3-class group. We prove a series of results related to the set of rational points , and the -equivalence classes of irreducible integral binary cubic forms of discriminant D. By assuming finiteness of the Tate-Shafarevich group, we derive a parity result between the rank of and the rank of its 3-Selmer group, and we establish lower and upper bounds for the rank of our elliptic curves. Finally, we give explicit classes of genus-1 curves that correspond to irreducible integral binary cubic forms of discriminant , and we show that every curve in these classes violates the Hasse Principle.
{"title":"On the Selmer group and rank of a family of elliptic curves and curves of genus one violating the Hasse principle","authors":"Eleni Agathocleous","doi":"10.1016/j.jnt.2024.08.001","DOIUrl":"10.1016/j.jnt.2024.08.001","url":null,"abstract":"<div><div>We study an infinite family of <em>j</em>-invariant zero elliptic curves <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>D</mi></mrow></msub><mo>:</mo><msup><mrow><mi>y</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>=</mo><msup><mrow><mi>x</mi></mrow><mrow><mn>3</mn></mrow></msup><mo>+</mo><mn>16</mn><mi>D</mi></math></span> and their <em>λ</em>-isogenous curves <span><math><msub><mrow><mi>E</mi></mrow><mrow><msup><mrow><mi>D</mi></mrow><mrow><mo>′</mo></mrow></msup></mrow></msub><mo>:</mo><msup><mrow><mi>y</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>=</mo><msup><mrow><mi>x</mi></mrow><mrow><mn>3</mn></mrow></msup><mo>−</mo><mn>27</mn><mo>⋅</mo><mn>16</mn><mi>D</mi></math></span>, where <em>D</em> and <span><math><msup><mrow><mi>D</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>=</mo><mo>−</mo><mn>3</mn><mi>D</mi></math></span> are fundamental discriminants of a specific form, and <em>λ</em> is an isogeny of degree 3. A result of Honda guarantees that for our discriminants <em>D</em>, the quadratic number field <span><math><msub><mrow><mi>K</mi></mrow><mrow><mi>D</mi></mrow></msub><mo>=</mo><mi>Q</mi><mo>(</mo><msqrt><mrow><mi>D</mi></mrow></msqrt><mo>)</mo></math></span> always has non-trivial 3-class group. We prove a series of results related to the set of rational points <span><math><msub><mrow><mi>E</mi></mrow><mrow><msup><mrow><mi>D</mi></mrow><mrow><mo>′</mo></mrow></msup></mrow></msub><mo>(</mo><mi>Q</mi><mo>)</mo><mo>∖</mo><mi>λ</mi><mo>(</mo><msub><mrow><mi>E</mi></mrow><mrow><mi>D</mi></mrow></msub><mo>(</mo><mi>Q</mi><mo>)</mo><mo>)</mo></math></span>, and the <span><math><mi>S</mi><mi>L</mi><mo>(</mo><mn>2</mn><mo>,</mo><mi>Z</mi><mo>)</mo></math></span>-equivalence classes of irreducible integral binary cubic forms of discriminant <em>D</em>. By assuming finiteness of the Tate-Shafarevich group, we derive a parity result between the rank of <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>D</mi></mrow></msub></math></span> and the rank of its 3-Selmer group, and we establish lower and upper bounds for the rank of our elliptic curves. Finally, we give explicit classes of genus-1 curves that correspond to irreducible integral binary cubic forms of discriminant <span><math><mi>D</mi><mo>=</mo><mn>48035713</mn></math></span>, and we show that every curve in these classes violates the Hasse Principle.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"267 ","pages":"Pages 101-133"},"PeriodicalIF":0.6,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328257","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 : 2024-09-23DOI: 10.1016/j.jnt.2024.07.014
Peijiang Liu
An ℓ-adic GKZ hypergeometric sheaf is defined analogously to a GKZ hypergeometric -module. We introduce an algorithm of computing the characteristic cycle of an ℓ-adic GKZ hypergeometric sheaf of certain type. Our strategy is to apply a formula of the characteristic cycle of the direct image of an ℓ-adic sheaf. We verify the requirements for the formula to hold by calculating the dimension of the direct image of a certain closed conical subset of cotangent bundle. We also define an ℓ-adic GKZ-type sheaf whose specialization tensored with a constant sheaf is isomorphic to an ℓ-adic non-confluent GKZ hypergeometric sheaf. On the other hand, the topological model of an ℓ-adic GKZ-type sheaf is isomorphic to the image by the de Rham functor of a non-confluent GKZ hypergeometric -module whose characteristic cycle has been calculated. This gives an easier way to determine the characteristic cycle of an ℓ-adic non-confluent GKZ hypergeometric sheaf of certain type.
{"title":"The characteristic cycle of a non-confluent ℓ-adic GKZ hypergeometric sheaf","authors":"Peijiang Liu","doi":"10.1016/j.jnt.2024.07.014","DOIUrl":"10.1016/j.jnt.2024.07.014","url":null,"abstract":"<div><div>An <em>ℓ</em>-adic GKZ hypergeometric sheaf is defined analogously to a GKZ hypergeometric <span><math><mi>D</mi></math></span>-module. We introduce an algorithm of computing the characteristic cycle of an <em>ℓ</em>-adic GKZ hypergeometric sheaf of certain type. Our strategy is to apply a formula of the characteristic cycle of the direct image of an <em>ℓ</em>-adic sheaf. We verify the requirements for the formula to hold by calculating the dimension of the direct image of a certain closed conical subset of cotangent bundle. We also define an <em>ℓ</em>-adic GKZ-type sheaf whose specialization tensored with a constant sheaf is isomorphic to an <em>ℓ</em>-adic non-confluent GKZ hypergeometric sheaf. On the other hand, the topological model of an <em>ℓ</em>-adic GKZ-type sheaf is isomorphic to the image by the de Rham functor of a non-confluent GKZ hypergeometric <span><math><mi>D</mi></math></span>-module whose characteristic cycle has been calculated. This gives an easier way to determine the characteristic cycle of an <em>ℓ</em>-adic non-confluent GKZ hypergeometric sheaf of certain type.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"267 ","pages":"Pages 1-33"},"PeriodicalIF":0.6,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328258","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 : 2024-09-23DOI: 10.1016/j.jnt.2024.08.006
Takeshi Ogasawara , George J. Schaeffer
We present new examples of and number fields ramified at a single prime. To find these number fields we employ the following methods: (i) Specializing a modification of Malle's polynomial, (ii) Modular method: computation of Katz modular forms of weight one over with prime level, and (iii) Searching for polynomials with prescribed ramification.
Method (i) quickly generates many number fields unramified at 7 including those fields ramified at only a single prime. Method (ii) can be used to show the existence of or number fields ramified only at primes that divide the level; we can then use method (iii) to find polynomials for those fields in many cases.
{"title":"On PGL2(F7) and PSL2(F7) number fields ramified at a single prime","authors":"Takeshi Ogasawara , George J. Schaeffer","doi":"10.1016/j.jnt.2024.08.006","DOIUrl":"10.1016/j.jnt.2024.08.006","url":null,"abstract":"<div><div>We present new examples of <span><math><msub><mrow><mi>PGL</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>(</mo><msub><mrow><mi>F</mi></mrow><mrow><mn>7</mn></mrow></msub><mo>)</mo></math></span> and <span><math><msub><mrow><mi>PSL</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>(</mo><msub><mrow><mi>F</mi></mrow><mrow><mn>7</mn></mrow></msub><mo>)</mo></math></span> number fields ramified at a single prime. To find these number fields we employ the following methods: (i) Specializing a modification of Malle's <span><math><msub><mrow><mi>PGL</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>(</mo><msub><mrow><mi>F</mi></mrow><mrow><mn>7</mn></mrow></msub><mo>)</mo></math></span> polynomial, (ii) Modular method: computation of Katz modular forms of weight one over <span><math><msub><mrow><mover><mrow><mi>F</mi></mrow><mo>‾</mo></mover></mrow><mrow><mn>7</mn></mrow></msub></math></span> with prime level, and (iii) Searching for polynomials with prescribed ramification.</div><div>Method (i) quickly generates many <span><math><msub><mrow><mi>PGL</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>(</mo><msub><mrow><mi>F</mi></mrow><mrow><mn>7</mn></mrow></msub><mo>)</mo></math></span> number fields unramified at 7 including those fields ramified at only a single prime. Method (ii) can be used to show the existence of <span><math><msub><mrow><mi>PGL</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>(</mo><msub><mrow><mi>F</mi></mrow><mrow><mn>7</mn></mrow></msub><mo>)</mo></math></span> or <span><math><msub><mrow><mi>PSL</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>(</mo><msub><mrow><mi>F</mi></mrow><mrow><mn>7</mn></mrow></msub><mo>)</mo></math></span> number fields ramified only at primes that divide the level; we can then use method (iii) to find polynomials for those fields in many cases.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"267 ","pages":"Pages 202-220"},"PeriodicalIF":0.6,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425201","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 : 2024-09-23DOI: 10.1016/j.jnt.2024.08.002
Aliaksei Semchankau
For a large prime number p and a set we prove the following:
(1)
If does not cover all nonzero residues in , then .
(2)
If A is both sum-free and satisfies , then .
(3)
If , then .
Here the constants 1/8, 1/9, 2 are the best possible. Proofs make use of wrappers, subsets of a finite abelian group G, which ‘wrap’ popular values in convolutions of dense sets . These objects carry certain structural features, making them capable of addressing additive-combinatorial and enumerative problems.
对于一个大素数 p 和一个集合 A⊂Fp,我们证明如下:(1)如果 A(A+A) 没有覆盖 Fp 中的所有非零残差,那么 |A|⩽p/8+o(p)。(2)如果 A 既无和且满足 A=A⁎,则|A|⩽p/9+o(p)。 (3)如果|A|≫loglogplogpp,则|A+A⁎|⩾(1+o(1))min(2|A|p,p)。这里的常数 1/8、1/9、2 是可能的最佳值。这些对象具有某些结构特征,使它们能够解决加法组合问题和枚举问题。
{"title":"A new bound for A(A + A) for large sets","authors":"Aliaksei Semchankau","doi":"10.1016/j.jnt.2024.08.002","DOIUrl":"10.1016/j.jnt.2024.08.002","url":null,"abstract":"<div><div>For a large prime number <em>p</em> and a set <span><math><mi>A</mi><mo>⊂</mo><msub><mrow><mi>F</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> we prove the following:<ul><li><span>(1)</span><span><div>If <span><math><mi>A</mi><mo>(</mo><mi>A</mi><mo>+</mo><mi>A</mi><mo>)</mo></math></span> does not cover all nonzero residues in <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>, then <span><math><mo>|</mo><mi>A</mi><mo>|</mo><mo>⩽</mo><mi>p</mi><mo>/</mo><mn>8</mn><mo>+</mo><mi>o</mi><mo>(</mo><mi>p</mi><mo>)</mo></math></span>.</div></span></li><li><span>(2)</span><span><div>If <em>A</em> is both sum-free and satisfies <span><math><mi>A</mi><mo>=</mo><msup><mrow><mi>A</mi></mrow><mrow><mo>⁎</mo></mrow></msup></math></span>, then <span><math><mo>|</mo><mi>A</mi><mo>|</mo><mo>⩽</mo><mi>p</mi><mo>/</mo><mn>9</mn><mo>+</mo><mi>o</mi><mo>(</mo><mi>p</mi><mo>)</mo></math></span>.</div></span></li><li><span>(3)</span><span><div>If <span><math><mo>|</mo><mi>A</mi><mo>|</mo><mo>≫</mo><mfrac><mrow><mi>log</mi><mo></mo><mi>log</mi><mo></mo><mi>p</mi></mrow><mrow><msqrt><mrow><mi>log</mi><mo></mo><mi>p</mi></mrow></msqrt></mrow></mfrac><mi>p</mi></math></span>, then <span><math><mo>|</mo><mi>A</mi><mo>+</mo><msup><mrow><mi>A</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>|</mo><mo>⩾</mo><mo>(</mo><mn>1</mn><mo>+</mo><mi>o</mi><mo>(</mo><mn>1</mn><mo>)</mo><mo>)</mo><mi>min</mi><mo></mo><mo>(</mo><mn>2</mn><msqrt><mrow><mo>|</mo><mi>A</mi><mo>|</mo><mi>p</mi></mrow></msqrt><mo>,</mo><mi>p</mi><mo>)</mo></math></span>.</div></span></li></ul> Here the constants 1/8, 1/9, 2 are the best possible. Proofs make use of <em>wrappers</em>, subsets of a finite abelian group <em>G</em>, which ‘wrap’ popular values in convolutions of dense sets <span><math><mi>A</mi><mo>,</mo><mi>B</mi><mo>⊆</mo><mi>G</mi></math></span>. These objects carry certain structural features, making them capable of addressing additive-combinatorial and enumerative problems.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"268 ","pages":"Pages 142-162"},"PeriodicalIF":0.6,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699245","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 : 2024-09-20DOI: 10.1016/j.jnt.2024.08.004
José Cunha , Pedro Freitas
We develop a unified method to study spectral determinants for several different manifolds, including spheres and hemispheres, and projective spaces. This is a direct consequence of an approach based on deriving recursion relations for the corresponding zeta functions, which we are then able to solve explicitly. Apart from new applications such as hemispheres, we also believe that the resulting formulae in the cases for which expressions for the determinant were already known are simpler and easier to compute in general, when compared to those resulting from other approaches.
{"title":"Recurrence formulae for spectral determinants","authors":"José Cunha , Pedro Freitas","doi":"10.1016/j.jnt.2024.08.004","DOIUrl":"10.1016/j.jnt.2024.08.004","url":null,"abstract":"<div><div>We develop a unified method to study spectral determinants for several different manifolds, including spheres and hemispheres, and projective spaces. This is a direct consequence of an approach based on deriving recursion relations for the corresponding zeta functions, which we are then able to solve explicitly. Apart from new applications such as hemispheres, we also believe that the resulting formulae in the cases for which expressions for the determinant were already known are simpler and easier to compute in general, when compared to those resulting from other approaches.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"267 ","pages":"Pages 134-175"},"PeriodicalIF":0.6,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328242","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 : 2024-08-30DOI: 10.1016/j.jnt.2024.07.005
Rafael von Känel
The strategy of combining the method of Faltings (Arakelov, Paršin, Szpiro) with modularity and Masser–Wüstholz isogeny estimates allows to explicitly bound the height and the number of the solutions of certain Diophantine equations related to integral points on moduli schemes of abelian varieties. In this paper we survey the development and various applications of this strategy.
{"title":"Integral points on moduli schemes","authors":"Rafael von Känel","doi":"10.1016/j.jnt.2024.07.005","DOIUrl":"https://doi.org/10.1016/j.jnt.2024.07.005","url":null,"abstract":"The strategy of combining the method of Faltings (Arakelov, Paršin, Szpiro) with modularity and Masser–Wüstholz isogeny estimates allows to explicitly bound the height and the number of the solutions of certain Diophantine equations related to integral points on moduli schemes of abelian varieties. In this paper we survey the development and various applications of this strategy.","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"43 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260799","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}