{"title":"<ArticleTitle xmlns:ns0=\"http://www.w3.org/1998/Math/MathML\">Summing <ns0:math><ns0:mrow><ns0:mi>μ</ns0:mi> <ns0:mo>(</ns0:mo> <ns0:mi>n</ns0:mi> <ns0:mo>)</ns0:mo></ns0:mrow> </ns0:math> : a faster elementary algorithm.","authors":"Harald Andrés Helfgott, Lola Thompson","doi":"10.1007/s40993-022-00408-8","DOIUrl":"https://doi.org/10.1007/s40993-022-00408-8","url":null,"abstract":"<p><p>We present a new elementary algorithm that takes <math><mrow><mtext>time</mtext> <mspace></mspace> <mspace></mspace> <msub><mi>O</mi> <mi>ϵ</mi></msub> <mfenced><msup><mi>x</mi> <mfrac><mn>3</mn> <mn>5</mn></mfrac> </msup> <msup><mrow><mo>(</mo> <mo>log</mo> <mi>x</mi> <mo>)</mo></mrow> <mrow><mfrac><mn>8</mn> <mn>5</mn></mfrac> <mo>+</mo> <mi>ϵ</mi></mrow> </msup> </mfenced> <mspace></mspace> <mspace></mspace> <mtext>and</mtext> <mspace></mspace> <mtext>space</mtext> <mspace></mspace> <mspace></mspace> <mi>O</mi> <mfenced><msup><mi>x</mi> <mfrac><mn>3</mn> <mn>10</mn></mfrac> </msup> <msup><mrow><mo>(</mo> <mo>log</mo> <mi>x</mi> <mo>)</mo></mrow> <mfrac><mn>13</mn> <mn>10</mn></mfrac> </msup> </mfenced> </mrow> </math> (measured bitwise) for computing <math><mrow><mi>M</mi> <mrow><mo>(</mo> <mi>x</mi> <mo>)</mo></mrow> <mo>=</mo> <msub><mo>∑</mo> <mrow><mi>n</mi> <mo>≤</mo> <mi>x</mi></mrow> </msub> <mi>μ</mi> <mrow><mo>(</mo> <mi>n</mi> <mo>)</mo></mrow> <mo>,</mo></mrow> </math> where <math><mrow><mi>μ</mi> <mo>(</mo> <mi>n</mi> <mo>)</mo></mrow> </math> is the Möbius function. This is the first improvement in the exponent of <i>x</i> for an elementary algorithm since 1985. We also show that it is possible to reduce space consumption to <math><mrow><mi>O</mi> <mo>(</mo> <msup><mi>x</mi> <mrow><mn>1</mn> <mo>/</mo> <mn>5</mn></mrow> </msup> <msup><mrow><mo>(</mo> <mo>log</mo> <mi>x</mi> <mo>)</mo></mrow> <mrow><mn>5</mn> <mo>/</mo> <mn>3</mn></mrow> </msup> <mo>)</mo></mrow> </math> by the use of (Helfgott in: Math Comput 89:333-350, 2020), at the cost of letting time rise to the order of <math> <mrow><msup><mi>x</mi> <mrow><mn>3</mn> <mo>/</mo> <mn>5</mn></mrow> </msup> <msup><mrow><mo>(</mo> <mo>log</mo> <mi>x</mi> <mo>)</mo></mrow> <mn>2</mn></msup> <mo>log</mo> <mo>log</mo> <mi>x</mi></mrow> </math> .</p>","PeriodicalId":43826,"journal":{"name":"Research in Number Theory","volume":"9 1","pages":"6"},"PeriodicalIF":0.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9731940/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10687746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Geometric sieve over number fields for higher moments.","authors":"Giacomo Micheli, Severin Schraven, Simran Tinani, Violetta Weger","doi":"10.1007/s40993-023-00466-6","DOIUrl":"10.1007/s40993-023-00466-6","url":null,"abstract":"<p><p>The geometric sieve for densities is a very convenient tool proposed by Poonen and Stoll (and independently by Ekedahl) to compute the density of a given subset of the integers. In this paper we provide an effective criterion to find all higher moments of the density (e.g. the mean, the variance) of a subset of a finite dimensional free module over the ring of algebraic integers of a number field. More precisely, we provide a geometric sieve that allows the computation of all higher moments corresponding to the density, over a general number field <i>K</i>. This work advances the understanding of geometric sieve for density computations in two ways: on one hand, it extends a result of Bright, Browning and Loughran, where they provide the geometric sieve for densities over number fields; on the other hand, it extends the recent result on a geometric sieve for expected values over the integers to both the ring of algebraic integers and to moments higher than the expected value. To show how effective and applicable our method is, we compute the density, mean and variance of Eisenstein polynomials and shifted Eisenstein polynomials over number fields. This extends (and fully covers) results in the literature that were obtained with ad-hoc methods.</p>","PeriodicalId":43826,"journal":{"name":"Research in Number Theory","volume":"9 3","pages":"62"},"PeriodicalIF":0.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10397131/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9943903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"<i>p</i>-adic vertex operator algebras.","authors":"Cameron Franc, Geoffrey Mason","doi":"10.1007/s40993-023-00433-1","DOIUrl":"https://doi.org/10.1007/s40993-023-00433-1","url":null,"abstract":"<p><p>We postulate axioms for a chiral half of a nonarchimedean 2-dimensional bosonic conformal field theory, that is, a vertex operator algebra in which a <i>p</i>-adic Banach space replaces the traditional Hilbert space. We study some consequences of our axioms leading to the construction of various examples, including <i>p</i>-adic commutative Banach rings and <i>p</i>-adic versions of the Virasoro, Heisenberg, and the Moonshine module vertex operator algebras. Serre <i>p</i>-adic modular forms occur naturally in some of these examples as limits of classical 1-point functions.</p>","PeriodicalId":43826,"journal":{"name":"Research in Number Theory","volume":"9 2","pages":"27"},"PeriodicalIF":0.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10071837/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9289144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Kampé de Fériet hypergeometric functions over finite fields","authors":"Ryojun Ito, Satoshi Kumabe, Akio Nakagawa, Yusuke Nemoto","doi":"10.1007/s40993-023-00460-y","DOIUrl":"https://doi.org/10.1007/s40993-023-00460-y","url":null,"abstract":"","PeriodicalId":43826,"journal":{"name":"Research in Number Theory","volume":"25 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90279150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fast change of level and applications to isogenies","authors":"D. Lubicz, Damien Robert","doi":"10.1007/s40993-022-00407-9","DOIUrl":"https://doi.org/10.1007/s40993-022-00407-9","url":null,"abstract":"","PeriodicalId":43826,"journal":{"name":"Research in Number Theory","volume":"26 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81124136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Triangular modular curves of small genus","authors":"Juanita Duque-Rosero, J. Voight","doi":"10.1007/s40993-022-00395-w","DOIUrl":"https://doi.org/10.1007/s40993-022-00395-w","url":null,"abstract":"","PeriodicalId":43826,"journal":{"name":"Research in Number Theory","volume":"285 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72443235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Rogers–Ramanujan type generalized reciprocal identities and Eisenstein series","authors":"Zafer Selcuk Aygin","doi":"10.1007/s40993-022-00416-8","DOIUrl":"https://doi.org/10.1007/s40993-022-00416-8","url":null,"abstract":"","PeriodicalId":43826,"journal":{"name":"Research in Number Theory","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88716266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Modular forms via invariant theory","authors":"Fabien Cl'ery, G. van der Geer","doi":"10.1007/s40993-023-00442-0","DOIUrl":"https://doi.org/10.1007/s40993-023-00442-0","url":null,"abstract":"","PeriodicalId":43826,"journal":{"name":"Research in Number Theory","volume":"47 1","pages":"1-10"},"PeriodicalIF":0.8,"publicationDate":"2022-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80664305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Computing torsion subgroups of Jacobians of hyperelliptic curves of genus 3","authors":"J. Müller, Berno Reitsma","doi":"10.1007/s40993-023-00429-x","DOIUrl":"https://doi.org/10.1007/s40993-023-00429-x","url":null,"abstract":"","PeriodicalId":43826,"journal":{"name":"Research in Number Theory","volume":"23 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80787292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correction: Examples of abelian surfaces failing the local-global principle for isogenies","authors":"Barinder S. Banwait","doi":"10.1007/s40993-022-00406-w","DOIUrl":"https://doi.org/10.1007/s40993-022-00406-w","url":null,"abstract":"","PeriodicalId":43826,"journal":{"name":"Research in Number Theory","volume":"70 1","pages":"1-3"},"PeriodicalIF":0.8,"publicationDate":"2022-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90239827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}