Bulletin of the London Mathematical Society最新文献

{"title":"Obstructing Anosov flows on cusped 3-manifolds","authors":"Misha Schmalian","doi":"10.1112/blms.70049","DOIUrl":"https://doi.org/10.1112/blms.70049","url":null,"abstract":"<p>Using results relating taut foliations, Heegaard–Floer homology and pseudo-Anosov flows, we find cusped hyperbolic 3-manifolds which are not the non-singular part of a pseudo-Anosov flow. In particular, we find the first examples of cusped hyperbolic 3-manifolds not admitting veering triangulations, confirming a conjecture of S. Schleimer.</p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 5","pages":"1584-1592"},"PeriodicalIF":0.8,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1112/blms.70049","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938792","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}

{"title":"Remarks on \u0000 \u0000 τ\u0000 $tau$\u0000 -tilted versions of the second Brauer–Thrall conjecture","authors":"Calvin Pfeifer","doi":"10.1112/blms.70048","DOIUrl":"https://doi.org/10.1112/blms.70048","url":null,"abstract":"<p>In this short note, we state a stable and a <span></span><math>\u0000 <semantics>\u0000 <mi>τ</mi>\u0000 <annotation>$tau$</annotation>\u0000 </semantics></math>-reduced version of the second Brauer–Thrall conjecture. The former is a slight strengthening of a brick version of the second Brauer–Thrall conjecture raised by Mousavand and Schroll–Treffinger–Valdivieso. The latter is stated in terms of Geiß–Leclerc–Schröer's generically <span></span><math>\u0000 <semantics>\u0000 <mi>τ</mi>\u0000 <annotation>$tau$</annotation>\u0000 </semantics></math>-reduced components and provides a geometric interpretation of a question of Demonet. It follows that the stable second Brauer–Thrall conjecture implies our <span></span><math>\u0000 <semantics>\u0000 <mi>τ</mi>\u0000 <annotation>$tau$</annotation>\u0000 </semantics></math>-reduced second Brauer–Thrall conjecture. Finally, we prove the reversed implication for the class of <span></span><math>\u0000 <semantics>\u0000 <mi>E</mi>\u0000 <annotation>$E$</annotation>\u0000 </semantics></math>-tame algebras recently introduced by Asai–Iyama.</p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 5","pages":"1568-1583"},"PeriodicalIF":0.8,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1112/blms.70048","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143939440","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}

{"title":"Discrete subgroups of normed spaces are free","authors":"Tomasz Kania,&nbsp;Ziemowit Kostana","doi":"10.1112/blms.70051","DOIUrl":"https://doi.org/10.1112/blms.70051","url":null,"abstract":"<p>Ancel, Dobrowolski and Grabowski (<i>Studia Math</i>. 109 (1994): 277–290) proved that every countable discrete subgroup of the additive group of a normed space is free Abelian, hence isomorphic to the direct sum of a certain number of copies of the additive group of the integers. In the present paper, we take a set-theoretic approach based on the theory of elementary submodels and the Singular Compactness Theorem to remove the cardinality constraint from their result and prove that indeed every discrete subgroup of the additive group of a normed space is free Abelian.</p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 6","pages":"1650-1655"},"PeriodicalIF":0.8,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1112/blms.70051","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144244735","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}

{"title":"Rainbow stackings of random edge-colorings","authors":"Noga Alon,&nbsp;Colin Defant,&nbsp;Noah Kravitz","doi":"10.1112/blms.70052","DOIUrl":"https://doi.org/10.1112/blms.70052","url":null,"abstract":"<p>A <i>rainbow stacking</i> of <span></span><math>\u0000 <semantics>\u0000 <mi>r</mi>\u0000 <annotation>$r$</annotation>\u0000 </semantics></math>-edge-colorings <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>χ</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 <mo>,</mo>\u0000 <mtext>…</mtext>\u0000 <mo>,</mo>\u0000 <msub>\u0000 <mi>χ</mi>\u0000 <mi>m</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$chi _1, ldots , chi _m$</annotation>\u0000 </semantics></math> of the complete graph on <span></span><math>\u0000 <semantics>\u0000 <mi>n</mi>\u0000 <annotation>$n$</annotation>\u0000 </semantics></math> vertices is a way of superimposing <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>χ</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 <mo>,</mo>\u0000 <mtext>…</mtext>\u0000 <mo>,</mo>\u0000 <msub>\u0000 <mi>χ</mi>\u0000 <mi>m</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$chi _1, ldots , chi _m$</annotation>\u0000 </semantics></math> so that no edges of the same color are superimposed on each other. We determine a sharp threshold for <span></span><math>\u0000 <semantics>\u0000 <mi>r</mi>\u0000 <annotation>$r$</annotation>\u0000 </semantics></math> (as a function of <span></span><math>\u0000 <semantics>\u0000 <mi>m</mi>\u0000 <annotation>$m$</annotation>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <mi>n</mi>\u0000 <annotation>$n$</annotation>\u0000 </semantics></math>) governing the existence and nonexistence of rainbow stackings of random <span></span><math>\u0000 <semantics>\u0000 <mi>r</mi>\u0000 <annotation>$r$</annotation>\u0000 </semantics></math>-edge-colorings <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>χ</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 <mo>,</mo>\u0000 <mtext>…</mtext>\u0000 <mo>,</mo>\u0000 <msub>\u0000 <mi>χ</mi>\u0000 <mi>m</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$chi _1,ldots ,chi _m$</annotation>\u0000 </semantics></math>.</p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 6","pages":"1656-1670"},"PeriodicalIF":0.8,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144244948","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}

{"title":"A note on cables and the involutive concordance invariants","authors":"Kristen Hendricks,&nbsp;Abhishek Mallick","doi":"10.1112/blms.70050","DOIUrl":"https://doi.org/10.1112/blms.70050","url":null,"abstract":"<p>We prove a formula for the involutive concordance invariants of the cabled knots in terms of those of the companion knot and the pattern knot. As a consequence, we show that any iterated cable of a knot with parameters of the form (odd,1) is not smoothly slice as long as either of the involutive concordance invariants of the knot is nonzero. Our formula also gives new bounds for the unknotting number of a cabled knot, which are sometimes stronger than other known bounds coming from knot Floer homology.</p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 5","pages":"1593-1604"},"PeriodicalIF":0.8,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1112/blms.70050","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143939140","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}

{"title":"On the continuity of solutions to anisotropic elliptic operators in the limiting case","authors":"Simone Ciani,&nbsp;Eurica Henriques,&nbsp;Igor I. Skrypnik","doi":"10.1112/blms.70047","DOIUrl":"https://doi.org/10.1112/blms.70047","url":null,"abstract":"<p>We show that local weak solutions to anisotropic elliptic equations with bounded and measurable coefficients, whose prototype is\u0000\u0000 </p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 5","pages":"1548-1567"},"PeriodicalIF":0.8,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1112/blms.70047","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143939098","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}

{"title":"The Hilton–Milnor theorem in higher topoi","authors":"Samuel Lavenir","doi":"10.1112/blms.70041","DOIUrl":"https://doi.org/10.1112/blms.70041","url":null,"abstract":"<p>In this note, we show that the classical theorem of Hilton–Milnor on finite wedges of suspension spaces remains valid in an arbitrary <span></span><math>\u0000 <semantics>\u0000 <mi>∞</mi>\u0000 <annotation>$infty$</annotation>\u0000 </semantics></math>-topos. Our result relies on a version of James' splitting proved in [Devalapurkar and Haine, Doc. Math. 26 (2021), 1423–1464] and uses only basic constructions native to any model of <span></span><math>\u0000 <semantics>\u0000 <mi>∞</mi>\u0000 <annotation>$infty$</annotation>\u0000 </semantics></math>-categories.</p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 5","pages":"1468-1481"},"PeriodicalIF":0.8,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1112/blms.70041","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143939118","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}

{"title":"On the isomorphism problem for monoids of product-one sequences","authors":"Alfred Geroldinger,&nbsp;Jun Seok Oh","doi":"10.1112/blms.70042","DOIUrl":"https://doi.org/10.1112/blms.70042","url":null,"abstract":"<p>Let <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>G</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 <annotation>$G_1$</annotation>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>G</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 <annotation>$G_2$</annotation>\u0000 </semantics></math> be torsion groups. We prove that the monoids of product-one sequences over <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>G</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 <annotation>$G_1$</annotation>\u0000 </semantics></math> and over <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>G</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 <annotation>$G_2$</annotation>\u0000 </semantics></math> are isomorphic if and only if the groups <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>G</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 <annotation>$G_1$</annotation>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>G</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 <annotation>$G_2$</annotation>\u0000 </semantics></math> are isomorphic. This was known before for abelian groups.</p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 5","pages":"1482-1495"},"PeriodicalIF":0.8,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1112/blms.70042","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143939053","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}

{"title":"Equal area partitions of the sphere with diameter bounds, via optimal transport","authors":"Jun Kitagawa,&nbsp;Asuka Takatsu","doi":"10.1112/blms.70045","DOIUrl":"https://doi.org/10.1112/blms.70045","url":null,"abstract":"<p>We prove existence of equal area partitions of the unit sphere via optimal transport methods, accompanied by diameter bounds written in terms of Monge–Kantorovich distances. This can be used to obtain bounds on the expectation of the maximum diameter of partition sets, when points are uniformly sampled from the sphere. An application to the computation of sliced Monge–Kantorovich distances is also presented.</p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 5","pages":"1524-1538"},"PeriodicalIF":0.8,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1112/blms.70045","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938904","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}

{"title":"Ulrich ranks of Veronese varieties and equivariant instantons","authors":"Daniele Faenzi,&nbsp;Victor Pretti","doi":"10.1112/blms.70046","DOIUrl":"https://doi.org/10.1112/blms.70046","url":null,"abstract":"<p>We construct Ulrich bundles on Veronese threefolds of arbitrary degree as generic deformations of symmetric squares of equivariant instanton bundles on the projective space, thus classifying the rank of Ulrich bundles on such varieties and proving a conjecture of Costa and Miró-Roig.</p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 5","pages":"1539-1547"},"PeriodicalIF":0.8,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938903","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}