Pub Date : 2025-10-01DOI: 10.1016/j.jnt.2025.09.003
Sara Chari , Sergio Ricardo Zapata Ceballos , Erik Holmes , Fatemeh Jalalvand , Rahinatou Yuh Njah Nchiwo , Kelly O'Connor , Fabian Ramirez , Sameera Vemulapalli
There has been a recent surge of interest on distributions of shapes of unit lattices in number fields, due to both their applications to number theory and the lack of known results.
In this work we focus on -quartic fields with signature ; such fields have a rank 2 unit group. Viewing the unit lattice as a point of , we prove that every lattice which arises this way must correspond to a transcendental point on the boundary of a certain fundamental domain of . Moreover, we produce three explicit (algebraic) points of which are limit points of the set of (points associated to) unit lattices of -quartic fields with signature .
{"title":"Unit lattices of D4-quartic number fields with signature (2,1)","authors":"Sara Chari , Sergio Ricardo Zapata Ceballos , Erik Holmes , Fatemeh Jalalvand , Rahinatou Yuh Njah Nchiwo , Kelly O'Connor , Fabian Ramirez , Sameera Vemulapalli","doi":"10.1016/j.jnt.2025.09.003","DOIUrl":"10.1016/j.jnt.2025.09.003","url":null,"abstract":"<div><div>There has been a recent surge of interest on distributions of shapes of unit lattices in number fields, due to both their applications to number theory and the lack of known results.</div><div>In this work we focus on <span><math><msub><mrow><mi>D</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span>-quartic fields with signature <span><math><mo>(</mo><mn>2</mn><mo>,</mo><mn>1</mn><mo>)</mo></math></span>; such fields have a rank 2 unit group. Viewing the unit lattice as a point of <span><math><msub><mrow><mi>GL</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>(</mo><mi>Z</mi><mo>)</mo><mo>﹨</mo><mi>h</mi></math></span>, we prove that every lattice which arises this way must correspond to a transcendental point on the boundary of a certain fundamental domain of <span><math><msub><mrow><mi>GL</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>(</mo><mi>Z</mi><mo>)</mo><mo>﹨</mo><mi>h</mi></math></span>. Moreover, we produce three explicit (algebraic) points of <span><math><msub><mrow><mi>GL</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>(</mo><mi>Z</mi><mo>)</mo><mo>﹨</mo><mi>h</mi></math></span> which are limit points of the set of (points associated to) unit lattices of <span><math><msub><mrow><mi>D</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span>-quartic fields with signature <span><math><mo>(</mo><mn>2</mn><mo>,</mo><mn>1</mn><mo>)</mo></math></span>.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"280 ","pages":"Pages 761-784"},"PeriodicalIF":0.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267055","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 : 2025-10-01DOI: 10.1016/j.jnt.2025.09.001
Wang-Xing Yu , Jun-Jia Zhao
Let be a fixed real number and be an integer. In 2023, Yu, Chen and Chen proved that for any sufficiently large positive integer n, if with and , then there is a power of r that can be represented as the sum of distinct elements of A, where is a computable positive integer only related to r. In this paper, we improve this result for . We prove that the condition can be replaced by , where is a computable positive integer only related to r. We will also show that this lower bound is optimal, namely, for infinitely many positive integers n, there exists with and such that no power of r can be represented as the sum of distinct elements of B. This also generalizes a result in which obtained by Yang and Zhao.
设ε>;0为固定实数,r≥2为整数。Yu、Chen、Chen在2023年证明了对于任何足够大的正整数n,当A≤gcd (A) =1,且| (A)≤|>(1/m(r)+ε)n时,则存在一个可表示为A的不同元素和的幂,其中m(r)是仅与r相关的可计算正整数。本文在r≥3时改进了这一结果。我们证明条件| |祝辞(1 / m (r) +ε)n可以取而代之的是| |在n / m (r) + f (r), f (r)是一个可计算的正整数仅与r。我们还将表明,该下界是最优的,即为无限多的正整数n,存在B⊆(1,n)肾小球疾病B = 1 B和| | = n / m (r) + f r (r),这样任何力量可以表示成不同的元素之和B .这也概括的结果r = 2通过杨和赵。
{"title":"An optimal lower bound for the size of the restricted sumsets containing powers","authors":"Wang-Xing Yu , Jun-Jia Zhao","doi":"10.1016/j.jnt.2025.09.001","DOIUrl":"10.1016/j.jnt.2025.09.001","url":null,"abstract":"<div><div>Let <span><math><mi>ε</mi><mo>></mo><mn>0</mn></math></span> be a fixed real number and <span><math><mi>r</mi><mo>≥</mo><mn>2</mn></math></span> be an integer. In 2023, Yu, Chen and Chen proved that for any sufficiently large positive integer <em>n</em>, if <span><math><mi>A</mi><mo>⊆</mo><mo>[</mo><mn>1</mn><mo>,</mo><mi>n</mi><mo>]</mo></math></span> with <span><math><mi>gcd</mi><mo></mo><mi>A</mi><mo>=</mo><mn>1</mn></math></span> and <span><math><mo>|</mo><mi>A</mi><mo>|</mo><mo>></mo><mo>(</mo><mn>1</mn><mo>/</mo><mi>m</mi><mo>(</mo><mi>r</mi><mo>)</mo><mo>+</mo><mi>ε</mi><mo>)</mo><mi>n</mi></math></span>, then there is a power of <em>r</em> that can be represented as the sum of distinct elements of <em>A</em>, where <span><math><mi>m</mi><mo>(</mo><mi>r</mi><mo>)</mo></math></span> is a computable positive integer only related to <em>r</em>. In this paper, we improve this result for <span><math><mi>r</mi><mo>≥</mo><mn>3</mn></math></span>. We prove that the condition <span><math><mo>|</mo><mi>A</mi><mo>|</mo><mo>></mo><mo>(</mo><mn>1</mn><mo>/</mo><mi>m</mi><mo>(</mo><mi>r</mi><mo>)</mo><mo>+</mo><mi>ε</mi><mo>)</mo><mi>n</mi></math></span> can be replaced by <span><math><mo>|</mo><mi>A</mi><mo>|</mo><mo>></mo><mi>n</mi><mo>/</mo><mi>m</mi><mo>(</mo><mi>r</mi><mo>)</mo><mo>+</mo><mi>f</mi><mo>(</mo><mi>r</mi><mo>)</mo></math></span>, where <span><math><mi>f</mi><mo>(</mo><mi>r</mi><mo>)</mo></math></span> is a computable positive integer only related to <em>r</em>. We will also show that this lower bound is optimal, namely, for infinitely many positive integers <em>n</em>, there exists <span><math><mi>B</mi><mo>⊆</mo><mo>[</mo><mn>1</mn><mo>,</mo><mi>n</mi><mo>]</mo></math></span> with <span><math><mi>gcd</mi><mo></mo><mi>B</mi><mo>=</mo><mn>1</mn></math></span> and <span><math><mo>|</mo><mi>B</mi><mo>|</mo><mo>=</mo><mi>n</mi><mo>/</mo><mi>m</mi><mo>(</mo><mi>r</mi><mo>)</mo><mo>+</mo><mi>f</mi><mo>(</mo><mi>r</mi><mo>)</mo></math></span> such that no power of <em>r</em> can be represented as the sum of distinct elements of <em>B</em>. This also generalizes a result in which <span><math><mi>r</mi><mo>=</mo><mn>2</mn></math></span> obtained by Yang and Zhao.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"280 ","pages":"Pages 785-807"},"PeriodicalIF":0.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267054","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 : 2025-10-01DOI: 10.1016/j.jnt.2025.09.004
Georges Gras
Let be an imaginary quadratic field. We consider the properties of capitulation of the p-class group of k in the anti-cyclotomic -extension of k; for this, using a new approach based on the -function (Theorem 2.3, Theorem 3.4), we determine the first layer of over k, and we show that some partial capitulation may exist in , even when is totally ramified. We have conjectured that this phenomenon of capitulation is specific of the -extensions of k, distinct from the cyclotomic one. For , we characterize a sub-family of fields k (Normal Split cases) for which is not linearly disjoint from the Hilbert class field (Theorem 5.1). No assumptions are made on the splitting of 3 in k and in , nor on the structures of their 3-class groups. Four pari/gp programs (7.1, 7.2, 7.3, 7.4 depending on the classification of Definition 2.10) are given, computing a defining cubic polynomial of , and the main invariants attached to the fields k, , ; some relations with Iwasawa's invariants are discussed (Theorem 9.6).
设k=Q(−m)为虚二次域。讨论了k的反切环zp -扩展kac中k的p类群的投降性质;为此,使用基于logp函数(定理2.3,定理3.4)的新方法,我们确定了kac/k的第一层k1ac,并且我们证明了即使kac/k完全分叉,k1ac中也可能存在部分投降。我们已经推测,这种投降现象是k的zp扩展所特有的,不同于切环现象。对于p=3,我们刻画了域k(正常分裂情况)的子族,其中kac与Hilbert类域(定理5.1)不是线性不相交。没有假设3在k和k f =Q(3m)中的分裂,也没有假设它们的3类群的结构。给出了四个pari/gp程序(7.1,7.2,7.3,7.4,取决于定义2.10的分类),计算了k1ac的定义三次多项式,以及附加到字段k, k, k1ac的主要不变量;讨论了与Iwasawa不变量的一些关系(定理9.6)。
{"title":"Initial layer of the anti-cyclotomic Zp-extension of Q(−m) and capitulation phenomenon","authors":"Georges Gras","doi":"10.1016/j.jnt.2025.09.004","DOIUrl":"10.1016/j.jnt.2025.09.004","url":null,"abstract":"<div><div>Let <span><math><mi>k</mi><mo>=</mo><mi>Q</mi><mo>(</mo><msqrt><mrow><mo>−</mo><mi>m</mi></mrow></msqrt><mo>)</mo></math></span> be an imaginary quadratic field. We consider the properties of capitulation of the <em>p</em>-class group of <em>k</em> in the anti-cyclotomic <span><math><msub><mrow><mi>Z</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>-extension <span><math><msup><mrow><mi>k</mi></mrow><mrow><mi>ac</mi></mrow></msup></math></span> of <em>k</em>; for this, using a new approach based on the <span><math><msub><mrow><mi>Log</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>-function (<span><span>Theorem 2.3</span></span>, <span><span>Theorem 3.4</span></span>), we determine the first layer <span><math><msubsup><mrow><mi>k</mi></mrow><mrow><mn>1</mn></mrow><mrow><mi>ac</mi></mrow></msubsup></math></span> of <span><math><msup><mrow><mi>k</mi></mrow><mrow><mi>ac</mi></mrow></msup></math></span> over <em>k</em>, and we show that some partial capitulation may exist in <span><math><msubsup><mrow><mi>k</mi></mrow><mrow><mn>1</mn></mrow><mrow><mi>ac</mi></mrow></msubsup></math></span>, even when <span><math><msup><mrow><mi>k</mi></mrow><mrow><mi>ac</mi></mrow></msup><mo>/</mo><mi>k</mi></math></span> is totally ramified. We have conjectured that this phenomenon of capitulation is specific of the <span><math><msub><mrow><mi>Z</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>-extensions of <em>k</em>, distinct from the cyclotomic one. For <span><math><mi>p</mi><mo>=</mo><mn>3</mn></math></span>, we characterize a sub-family of fields <em>k</em> (Normal Split cases) for which <span><math><msup><mrow><mi>k</mi></mrow><mrow><mi>ac</mi></mrow></msup></math></span> is not linearly disjoint from the Hilbert class field (<span><span>Theorem 5.1</span></span>). No assumptions are made on the splitting of 3 in <em>k</em> and in <span><math><msup><mrow><mi>k</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>=</mo><mi>Q</mi><mo>(</mo><msqrt><mrow><mn>3</mn><mi>m</mi></mrow></msqrt><mo>)</mo></math></span>, nor on the structures of their 3-class groups. Four <span>pari/gp</span> programs (<span><span>7.1</span></span>, <span><span>7.2</span></span>, <span><span>7.3</span></span>, <span><span>7.4</span></span> depending on the classification of <span><span>Definition 2.10</span></span>) are given, computing a defining cubic polynomial of <span><math><msubsup><mrow><mi>k</mi></mrow><mrow><mn>1</mn></mrow><mrow><mi>ac</mi></mrow></msubsup></math></span>, and the main invariants attached to the fields <em>k</em>, <span><math><msup><mrow><mi>k</mi></mrow><mrow><mo>⁎</mo></mrow></msup></math></span>, <span><math><msubsup><mrow><mi>k</mi></mrow><mrow><mn>1</mn></mrow><mrow><mi>ac</mi></mrow></msubsup></math></span>; some relations with Iwasawa's invariants are discussed (<span><span>Theorem 9.6</span></span>).</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"280 ","pages":"Pages 634-701"},"PeriodicalIF":0.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267235","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 : 2025-10-01DOI: 10.1016/j.jnt.2025.09.006
Zhigang Tian , Lulu Fang
In this paper, we study two problems concerning the relationship between regular continued fractions (RCFs) and backward continued fractions (BCFs). The first problem addresses Lochs-type theorems for RCFs and BCFs, where we compare the number of partial quotients in one expansion as a function of the number of partial quotients in the other expansion. The second problem investigates the approximation properties of RCFs and BCFs, with particular attention to the set of irrational numbers that are infinitely often better approximated by BCFs than by RCFs. We show that this set has Lebesgue measure zero and further analyze it from the perspectives of Baire category and fractal dimension.
{"title":"Comparing regular and backward continued fractions: Lochs-type theorems and approximation properties","authors":"Zhigang Tian , Lulu Fang","doi":"10.1016/j.jnt.2025.09.006","DOIUrl":"10.1016/j.jnt.2025.09.006","url":null,"abstract":"<div><div>In this paper, we study two problems concerning the relationship between regular continued fractions (RCFs) and backward continued fractions (BCFs). The first problem addresses Lochs-type theorems for RCFs and BCFs, where we compare the number of partial quotients in one expansion as a function of the number of partial quotients in the other expansion. The second problem investigates the approximation properties of RCFs and BCFs, with particular attention to the set of irrational numbers that are infinitely often better approximated by BCFs than by RCFs. We show that this set has Lebesgue measure zero and further analyze it from the perspectives of Baire category and fractal dimension.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"280 ","pages":"Pages 947-972"},"PeriodicalIF":0.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267042","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 : 2025-10-01DOI: 10.1016/j.jnt.2025.09.002
Ho Yun Jung , Ja Kyung Koo , Dong Hwa Shin , Gyucheol Shin
For a positive integer N, we define an extended modular function of level N motivated by physics and investigate its fundamental properties. Let K be an imaginary quadratic field, and let be an order in K of discriminant D. Let denote the ray class field of modulo . For , we provide an explicit description of the Galois group using special values of extended modular functions of level N and the definite form class group of discriminant D and level N.
{"title":"Extended modular functions and definite form class groups","authors":"Ho Yun Jung , Ja Kyung Koo , Dong Hwa Shin , Gyucheol Shin","doi":"10.1016/j.jnt.2025.09.002","DOIUrl":"10.1016/j.jnt.2025.09.002","url":null,"abstract":"<div><div>For a positive integer <em>N</em>, we define an extended modular function of level <em>N</em> motivated by physics and investigate its fundamental properties. Let <em>K</em> be an imaginary quadratic field, and let <span><math><mi>O</mi></math></span> be an order in <em>K</em> of discriminant <em>D</em>. Let <span><math><msub><mrow><mi>K</mi></mrow><mrow><mi>O</mi><mo>,</mo><mspace></mspace><mi>N</mi></mrow></msub></math></span> denote the ray class field of <span><math><mi>O</mi></math></span> modulo <span><math><mi>N</mi><mi>O</mi></math></span>. For <span><math><mi>N</mi><mo>≥</mo><mn>3</mn></math></span>, we provide an explicit description of the Galois group <span><math><mrow><mi>Gal</mi></mrow><mo>(</mo><msub><mrow><mi>K</mi></mrow><mrow><mi>O</mi><mo>,</mo><mspace></mspace><mi>N</mi></mrow></msub><mo>/</mo><mi>Q</mi><mo>)</mo></math></span> using special values of extended modular functions of level <em>N</em> and the definite form class group of discriminant <em>D</em> and level <em>N</em>.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"280 ","pages":"Pages 808-824"},"PeriodicalIF":0.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267052","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 : 2025-09-29DOI: 10.1016/j.jnt.2025.08.015
Víctor Hernández Barrios , Santiago Molina Blanco
In this note we define anticyclotomic p-adic measures attached to a modular elliptic curve E over a general number field F, a quadratic extension , and a set of places S of F above p. We study the exceptional zero phenomenon that arises when E has multiplicative reduction at some place in S. In this direction, we obtain p-adic Gross-Zagier formulas relating derivatives of the corresponding p-adic L-functions to the extended Mordell-Weil group of E. Our main result uses the recent construction of plectic points on elliptic curves due to Fornea and Gehrmann and generalizes their main result in [9]. We obtain a formula that computes the r-th derivative of the p-adic L-function, where r is the number of places in S where E has multiplicative reduction, in terms of plectic points and Tate periods of E.
{"title":"Exceptional zero formulas for anticyclotomic p-adic L-functions","authors":"Víctor Hernández Barrios , Santiago Molina Blanco","doi":"10.1016/j.jnt.2025.08.015","DOIUrl":"10.1016/j.jnt.2025.08.015","url":null,"abstract":"<div><div>In this note we define anticyclotomic <em>p</em>-adic measures attached to a modular elliptic curve <em>E</em> over a general number field <em>F</em>, a quadratic extension <span><math><mi>K</mi><mo>/</mo><mi>F</mi></math></span>, and a set of places <em>S</em> of <em>F</em> above <em>p</em>. We study the exceptional zero phenomenon that arises when <em>E</em> has multiplicative reduction at some place in <em>S</em>. In this direction, we obtain <em>p</em>-adic Gross-Zagier formulas relating derivatives of the corresponding <em>p</em>-adic L-functions to the extended Mordell-Weil group of <em>E</em>. Our main result uses the recent construction of plectic points on elliptic curves due to Fornea and Gehrmann and generalizes their main result in <span><span>[9]</span></span>. We obtain a formula that computes the <em>r</em>-th derivative of the <em>p</em>-adic L-function, where <em>r</em> is the number of places in <em>S</em> where <em>E</em> has multiplicative reduction, in terms of plectic points and Tate periods of <em>E</em>.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"280 ","pages":"Pages 583-633"},"PeriodicalIF":0.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267059","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 : 2025-09-25DOI: 10.1016/j.jnt.2025.08.021
Alexandre Dieguez
For a fixed irrational with a prescribed irrationality measure function, we study the correlation , where Δ is the Dirichlet error term in the divisor problem. When θ has a finite irrationality measure, it is known that decorrelation occurs at a rate expressible in terms of this measure. Strong decorrelation occurs for all positive irrationals, except possibly Liouville numbers. We show that for irrationals with a prescribed irrationality measure function ψ, decorrelation can be quantified in terms of .
{"title":"On certain correlations into the divisor problem","authors":"Alexandre Dieguez","doi":"10.1016/j.jnt.2025.08.021","DOIUrl":"10.1016/j.jnt.2025.08.021","url":null,"abstract":"<div><div>For a fixed irrational <span><math><mi>θ</mi><mo>></mo><mn>0</mn></math></span> with a prescribed irrationality measure function, we study the correlation <span><math><msubsup><mrow><mo>∫</mo></mrow><mrow><mn>1</mn></mrow><mrow><mi>X</mi></mrow></msubsup><mi>Δ</mi><mo>(</mo><mi>x</mi><mo>)</mo><mi>Δ</mi><mo>(</mo><mi>θ</mi><mi>x</mi><mo>)</mo><mi>d</mi><mi>x</mi></math></span>, where Δ is the Dirichlet error term in the divisor problem. When <em>θ</em> has a finite irrationality measure, it is known that decorrelation occurs at a rate expressible in terms of this measure. Strong decorrelation occurs for all positive irrationals, except possibly Liouville numbers. We show that for irrationals with a prescribed irrationality measure function <em>ψ</em>, decorrelation can be quantified in terms of <span><math><msup><mrow><mi>ψ</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"280 ","pages":"Pages 519-536"},"PeriodicalIF":0.7,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220654","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 : 2025-09-24DOI: 10.1016/j.jnt.2025.08.020
Nathaniel Kingsbury-Neuschotz
Let R be a finite ring (with identity, not necessarily commutative) and define the paraboloid . Suppose that for a sequence of finite rings of size tending to infinity, the Fourier transform of P satisfies a square-root law of the form for all nontrivial additive characters ψ, with C some fixed constant (for instance, if R is a finite field, this bound will be satisfied with ). Then all but finitely many of the rings are fields.
Most of our argument works in greater generality: let f be a polynomial with integer coefficients in variables, with a fixed order of variable multiplications (so that it defines a function even when R is noncommutative), and set . If (for a sequence of finite rings of size tending to infinity) we have a square root law for the Fourier transform of , then all but finitely many of the rings are fields or matrix rings of small dimension. We also describe how our techniques can establish that certain varieties do not satisfy a square root law
{"title":"The square-root law does not hold in the presence of zero divisors","authors":"Nathaniel Kingsbury-Neuschotz","doi":"10.1016/j.jnt.2025.08.020","DOIUrl":"10.1016/j.jnt.2025.08.020","url":null,"abstract":"<div><div>Let <em>R</em> be a finite ring (with identity, not necessarily commutative) and define the paraboloid <span><math><mi>P</mi><mo>=</mo><mo>{</mo><mo>(</mo><msub><mrow><mi>x</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><mo>…</mo><mo>,</mo><msub><mrow><mi>x</mi></mrow><mrow><mi>d</mi></mrow></msub><mo>)</mo><mo>∈</mo><msup><mrow><mi>R</mi></mrow><mrow><mi>d</mi></mrow></msup><mo>|</mo><msub><mrow><mi>x</mi></mrow><mrow><mi>d</mi></mrow></msub><mo>=</mo><msubsup><mrow><mi>x</mi></mrow><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></msubsup><mo>+</mo><mo>…</mo><mo>+</mo><msubsup><mrow><mi>x</mi></mrow><mrow><mi>d</mi><mo>−</mo><mn>1</mn></mrow><mrow><mn>2</mn></mrow></msubsup><mo>}</mo></math></span>. Suppose that for a sequence of finite rings of size tending to infinity, the Fourier transform of <em>P</em> satisfies a square-root law of the form <span><math><mo>|</mo><mover><mrow><mi>P</mi></mrow><mrow><mo>ˆ</mo></mrow></mover><mo>(</mo><mi>ψ</mi><mo>)</mo><mo>|</mo><mo>≤</mo><mi>C</mi><mo>|</mo><mi>R</mi><msup><mrow><mo>|</mo></mrow><mrow><mo>−</mo><mi>d</mi></mrow></msup><mo>|</mo><mi>P</mi><msup><mrow><mo>|</mo></mrow><mrow><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac></mrow></msup></math></span> for all nontrivial additive characters <em>ψ</em>, with <em>C</em> some fixed constant (for instance, if <em>R</em> is a finite field, this bound will be satisfied with <span><math><mi>C</mi><mo>=</mo><mn>1</mn></math></span>). Then all but finitely many of the rings are fields.</div><div>Most of our argument works in greater generality: let <em>f</em> be a polynomial with integer coefficients in <span><math><mi>d</mi><mo>−</mo><mn>1</mn></math></span> variables, with a fixed order of variable multiplications (so that it defines a function <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>d</mi><mo>−</mo><mn>1</mn></mrow></msup><mo>→</mo><mi>R</mi></math></span> even when <em>R</em> is noncommutative), and set <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>f</mi></mrow></msub><mo>=</mo><mo>{</mo><mo>(</mo><msub><mrow><mi>x</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><mo>…</mo><mo>,</mo><msub><mrow><mi>x</mi></mrow><mrow><mi>d</mi></mrow></msub><mo>)</mo><mo>∈</mo><msup><mrow><mi>R</mi></mrow><mrow><mi>d</mi></mrow></msup><mo>|</mo><msub><mrow><mi>x</mi></mrow><mrow><mi>d</mi></mrow></msub><mo>=</mo><mi>f</mi><mo>(</mo><msub><mrow><mi>x</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><mo>…</mo><mo>,</mo><msub><mrow><mi>x</mi></mrow><mrow><mi>d</mi><mo>−</mo><mn>1</mn></mrow></msub><mo>)</mo><mo>}</mo></math></span>. If (for a sequence of finite rings of size tending to infinity) we have a square root law for the Fourier transform of <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>f</mi></mrow></msub></math></span>, then all but finitely many of the rings are fields or matrix rings of small dimension. We also describe how our techniques can establish that certain varieties do not satisfy a square root law ","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"280 ","pages":"Pages 481-505"},"PeriodicalIF":0.7,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220605","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 : 2025-09-24DOI: 10.1016/j.jnt.2025.08.012
Rob Rockwood
We show that p-adic families of cohomology classes associated to symmetric spaces vary p-adically over small discs in weight space, without any ordinarity assumption. This generalises previous work of Loeffler, Zerbes and the author. Furthermore, we show that these families exhibit full variation in the cyclotomic direction, generalising previous constructions of Euler systems and p-adic L-functions. As an application we show that the Lemma–Flach Euler system of Loeffler–Skinner–Zerbes interpolates in Coleman families.
{"title":"Spherical varieties and non-ordinary families of cohomology classes","authors":"Rob Rockwood","doi":"10.1016/j.jnt.2025.08.012","DOIUrl":"10.1016/j.jnt.2025.08.012","url":null,"abstract":"<div><div>We show that <em>p</em>-adic families of cohomology classes associated to symmetric spaces vary <em>p</em>-adically over small discs in weight space, without any ordinarity assumption. This generalises previous work of Loeffler, Zerbes and the author. Furthermore, we show that these families exhibit full variation in the cyclotomic direction, generalising previous constructions of Euler systems and <em>p</em>-adic <em>L</em>-functions. As an application we show that the Lemma–Flach Euler system of Loeffler–Skinner–Zerbes interpolates in Coleman families.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"280 ","pages":"Pages 390-454"},"PeriodicalIF":0.7,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220703","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 : 2025-09-23DOI: 10.1016/j.jnt.2025.08.017
Timothy Page
Unconditional bounds on the sixth and eighth moments of the Riemann zeta function are improved by bounding twisted second and fourth moments that arise upon application of the Cauchy-Schwarz inequality and Hölder's inequality. An unconditional bound on the sixth moment of the derivative of the Riemann zeta function is also deduced.
{"title":"Unconditional lower bounds for the sixth and eighth moments of the Riemann zeta function","authors":"Timothy Page","doi":"10.1016/j.jnt.2025.08.017","DOIUrl":"10.1016/j.jnt.2025.08.017","url":null,"abstract":"<div><div>Unconditional bounds on the sixth and eighth moments of the Riemann zeta function are improved by bounding twisted second and fourth moments that arise upon application of the Cauchy-Schwarz inequality and Hölder's inequality. An unconditional bound on the sixth moment of the derivative of the Riemann zeta function is also deduced.</div></div>","PeriodicalId":50110,"journal":{"name":"Journal of Number Theory","volume":"280 ","pages":"Pages 318-369"},"PeriodicalIF":0.7,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220651","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}