Pub Date : 2026-01-01Epub Date: 2026-03-11DOI: 10.1007/s00208-026-03377-w
David Loeffler, Chris Williams
Let be a regular algebraic cuspidal automorphic representation (RACAR) of . When is p-nearly-ordinary for the maximal standard parabolic with Levi , we construct a p-adic L-function for . More precisely, we construct a (single) bounded measure on attached to , and show it interpolates all the critical values at p in the left-half of the critical strip for (for varying and j). This proves conjectures of Coates-Perrin-Riou and Panchishkin in this case. We also prove a corresponding result in the right half of the critical strip, assuming near-ordinarity for the other maximal standard parabolic. Our construction uses the theory of spherical varieties to build a "Betti Euler system", a norm-compatible system of classes in the Betti cohomology of a locally symmetric space for . We work in arbitrary cohomological weight, allow arbitrary ramification at p along the Levi factor of the standard parabolic, and make no self-duality assumption. We thus give the first constructions of p-adic L-functions for RACARs of of 'general type' (i.e. those that do not arise as functorial lifts) for any .
{"title":"<ArticleTitle xmlns:ns0=\"http://www.w3.org/1998/Math/MathML\"><i>P</i>-adic <i>L</i>-functions for <ns0:math><ns0:mrow><ns0:mtext>GL</ns0:mtext> <ns0:mo>(</ns0:mo> <ns0:mn>3</ns0:mn> <ns0:mo>)</ns0:mo></ns0:mrow></ns0:math>.","authors":"David Loeffler, Chris Williams","doi":"10.1007/s00208-026-03377-w","DOIUrl":"10.1007/s00208-026-03377-w","url":null,"abstract":"<p><p>Let <math><mi>Π</mi></math> be a regular algebraic cuspidal automorphic representation (RACAR) of <math> <mrow><msub><mtext>GL</mtext> <mn>3</mn></msub> <mrow><mo>(</mo> <msub><mi>A</mi> <mi>Q</mi></msub> <mo>)</mo></mrow> </mrow> </math> . When <math><mi>Π</mi></math> is <i>p</i>-nearly-ordinary for the maximal standard parabolic with Levi <math> <mrow><msub><mtext>GL</mtext> <mn>1</mn></msub> <mo>×</mo> <msub><mtext>GL</mtext> <mn>2</mn></msub> </mrow> </math> , we construct a <i>p</i>-adic <i>L</i>-function for <math><mi>Π</mi></math> . More precisely, we construct a (single) bounded measure <math> <mrow><msub><mi>L</mi> <mi>p</mi></msub> <mrow><mo>(</mo> <mi>Π</mi> <mo>)</mo></mrow> </mrow> </math> on <math><msubsup><mi>Z</mi> <mi>p</mi> <mo>×</mo></msubsup> </math> attached to <math><mi>Π</mi></math> , and show it interpolates all the critical values <math><mrow><mi>L</mi> <mo>(</mo> <mi>Π</mi> <mo>×</mo> <mi>η</mi> <mo>,</mo> <mo>-</mo> <mi>j</mi> <mo>)</mo></mrow> </math> at <i>p</i> in the left-half of the critical strip for <math><mi>Π</mi></math> (for varying <math><mi>η</mi></math> and <i>j</i>). This proves conjectures of Coates-Perrin-Riou and Panchishkin in this case. We also prove a corresponding result in the right half of the critical strip, assuming near-ordinarity for the other maximal standard parabolic. Our construction uses the theory of spherical varieties to build a \"Betti Euler system\", a norm-compatible system of classes in the Betti cohomology of a locally symmetric space for <math><msub><mtext>GL</mtext> <mn>3</mn></msub> </math> . We work in arbitrary cohomological weight, allow arbitrary ramification at <i>p</i> along the Levi factor of the standard parabolic, and make no self-duality assumption. We thus give the first constructions of <i>p</i>-adic <i>L</i>-functions for RACARs of <math> <mrow><msub><mtext>GL</mtext> <mi>n</mi></msub> <mrow><mo>(</mo> <msub><mi>A</mi> <mi>Q</mi></msub> <mo>)</mo></mrow> </mrow> </math> of 'general type' (i.e. those that do not arise as functorial lifts) for any <math><mrow><mi>n</mi> <mo>></mo> <mn>2</mn></mrow> </math> .</p>","PeriodicalId":18304,"journal":{"name":"Mathematische Annalen","volume":"394 4","pages":"96"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12979307/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147463638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2026-02-18DOI: 10.1007/s00208-026-03393-w
Jesse Jääsaari
We examine the distribution of zeroes of half-integral weight Hecke cusp forms on the manifold near a cusp at infinity. In analogue of the Ghosh-Sarnak conjecture for classical holomorphic Hecke cusp forms, one expects that almost all of the zeroes sufficiently close to this cusp lie on two vertical geodesics and as the weight tends to infinity. We show that, for of the half-integral weight Hecke cusp forms in the Kohnen plus subspaces with weight bounded by a large parameter K, the number of such "real" zeroes grows almost at the expected rate. We also obtain a weaker lower bound for the number of real zeroes that holds for a positive proportion of forms. One of the key ingredients is the estimation of averaged first and second moments of quadratic twists of modular L-functions.
研究了半积分权Hecke顶点形式在无穷远处顶点附近的流形Γ 0 (4) H上的零点分布。在经典全纯Hecke顶点形式的Ghosh-Sarnak猜想的类比中,人们期望当权趋于无穷时,几乎所有足够接近该顶点的零点都位于两条垂直测地线上Re (s) = - 1 / 2和Re (s) = 0。我们证明了在权值以大参数K为界的Kohnen +子空间中,对于< ε K 2 / (log K) 3 / 2 + ε的半积分权Hecke尖点形式,这种“实”零的数量几乎以预期的速率增长。我们还得到了一个较弱的实数0个数的下界,该下界适用于正比例的形式。模l函数二次扭转的平均一阶矩和平均二阶矩的估计是其中的一个关键成分。
{"title":"On the real zeroes of half-integral weight Hecke cusp forms.","authors":"Jesse Jääsaari","doi":"10.1007/s00208-026-03393-w","DOIUrl":"https://doi.org/10.1007/s00208-026-03393-w","url":null,"abstract":"<p><p>We examine the distribution of zeroes of half-integral weight Hecke cusp forms on the manifold <math> <mrow><msub><mi>Γ</mi> <mn>0</mn></msub> <mrow><mrow><mo>(</mo> <mn>4</mn> <mo>)</mo></mrow> <mo></mo> <mi>H</mi></mrow> </mrow> </math> near a cusp at infinity. In analogue of the Ghosh-Sarnak conjecture for classical holomorphic Hecke cusp forms, one expects that almost all of the zeroes sufficiently close to this cusp lie on two vertical geodesics <math><mrow><mtext>Re</mtext> <mo>(</mo> <mi>s</mi> <mo>)</mo> <mo>=</mo> <mo>-</mo> <mn>1</mn> <mo>/</mo> <mn>2</mn></mrow> </math> and <math><mrow><mtext>Re</mtext> <mo>(</mo> <mi>s</mi> <mo>)</mo> <mo>=</mo> <mn>0</mn></mrow> </math> as the weight tends to infinity. We show that, for <math> <mrow><msub><mo>≫</mo> <mi>ε</mi></msub> <msup><mi>K</mi> <mn>2</mn></msup> <mo>/</mo> <msup><mrow><mo>(</mo> <mo>log</mo> <mi>K</mi> <mo>)</mo></mrow> <mrow><mn>3</mn> <mo>/</mo> <mn>2</mn> <mo>+</mo> <mi>ε</mi></mrow> </msup> </mrow> </math> of the half-integral weight Hecke cusp forms in the Kohnen plus subspaces with weight bounded by a large parameter <i>K</i>, the number of such \"real\" zeroes grows almost at the expected rate. We also obtain a weaker lower bound for the number of real zeroes that holds for a positive proportion of forms. One of the key ingredients is the estimation of averaged first and second moments of quadratic twists of modular <i>L</i>-functions.</p>","PeriodicalId":18304,"journal":{"name":"Mathematische Annalen","volume":"394 3","pages":"54"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12917030/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147271367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2026-03-12DOI: 10.1007/s00208-026-03421-9
Andrea Poiatti
In this contribution we introduce a novel weak solution concept for two-phase volume-preserving mean curvature flow, having both properties of unconditional global-in-time existence and weak-strong uniqueness. These solutions extend the ones proposed by Hensel and Laux (J Differ Geom 130:209-268, 2025) for the standard mean curvature flow, and consist in evolving varifolds coupled with the phase volumes by a transport equation. First, we show that, in the same setting as in Takasao (Arch Ration Mech Anal 247:52, 2023), any sharp interface limit of solutions to a slightly modified nonlocal Allen-Cahn equation is a varifold solution according to our new definition. Secondly, we crucially introduce a new notion of volume-preserving gradient-flow calibrations, allowing the extended velocity vector field to point in the normal direction on the interface. We show that any sufficiently regular strong solution is calibrated in this sense. Finally, we prove that any classical solution to volume-preserving mean curvature flow, which is then automatically a calibrated flow, is unique in the class of our new varifold solutions.
{"title":"Varifold solutions to volume-preserving mean curvature flow: existence and weak-strong uniqueness.","authors":"Andrea Poiatti","doi":"10.1007/s00208-026-03421-9","DOIUrl":"10.1007/s00208-026-03421-9","url":null,"abstract":"<p><p>In this contribution we introduce a novel weak solution concept for two-phase volume-preserving mean curvature flow, having both properties of unconditional global-in-time existence and weak-strong uniqueness. These solutions extend the ones proposed by Hensel and Laux (J Differ Geom 130:209-268, 2025) for the standard mean curvature flow, and consist in evolving varifolds coupled with the phase volumes by a transport equation. First, we show that, in the same setting as in Takasao (Arch Ration Mech Anal 247:52, 2023), any sharp interface limit of solutions to a slightly modified nonlocal Allen-Cahn equation is a varifold solution according to our new definition. Secondly, we crucially introduce a new notion of volume-preserving gradient-flow calibrations, allowing the extended velocity vector field to point in the normal direction on the interface. We show that any sufficiently regular strong solution is calibrated in this sense. Finally, we prove that any classical solution to volume-preserving mean curvature flow, which is then automatically a calibrated flow, is unique in the class of our new varifold solutions.</p>","PeriodicalId":18304,"journal":{"name":"Mathematische Annalen","volume":"394 4","pages":"98"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12982210/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147463677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2026-02-13DOI: 10.1007/s00208-026-03348-1
Foivos Evangelopoulos-Ntemiris, Mark Veraar
In this paper, we investigate discrete regularity estimates for a broad class of temporal numerical schemes for parabolic stochastic evolution equations. We provide a characterization of discrete stochastic maximal -regularity in terms of its continuous counterpart, thereby establishing a unified framework that yields numerous new discrete regularity results. Moreover, as a consequence of the continuous-time theory, we establish several important properties of discrete stochastic maximal regularity such as extrapolation in the exponent p and with respect to a power weight. Furthermore, employing the -functional calculus, we derive a powerful discrete maximal estimate in the trace space norm for .
{"title":"Discrete stochastic maximal regularity.","authors":"Foivos Evangelopoulos-Ntemiris, Mark Veraar","doi":"10.1007/s00208-026-03348-1","DOIUrl":"10.1007/s00208-026-03348-1","url":null,"abstract":"<p><p>In this paper, we investigate discrete regularity estimates for a broad class of temporal numerical schemes for parabolic stochastic evolution equations. We provide a characterization of discrete stochastic maximal <math><msup><mi>ℓ</mi> <mi>p</mi></msup> </math> -regularity in terms of its continuous counterpart, thereby establishing a unified framework that yields numerous new discrete regularity results. Moreover, as a consequence of the continuous-time theory, we establish several important properties of discrete stochastic maximal regularity such as extrapolation in the exponent <i>p</i> and with respect to a power weight. Furthermore, employing the <math><msup><mi>H</mi> <mi>∞</mi></msup> </math> -functional calculus, we derive a powerful discrete maximal estimate in the trace space norm <math> <mrow><msub><mi>D</mi> <mi>A</mi></msub> <mrow><mo>(</mo> <mn>1</mn> <mo>-</mo> <mfrac><mn>1</mn> <mi>p</mi></mfrac> <mo>,</mo> <mi>p</mi> <mo>)</mo></mrow> </mrow> </math> for <math><mrow><mi>p</mi> <mo>∈</mo> <mo>[</mo> <mn>2</mn> <mo>,</mo> <mi>∞</mi> <mo>)</mo></mrow> </math> .</p>","PeriodicalId":18304,"journal":{"name":"Mathematische Annalen","volume":"394 2","pages":"42"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12904967/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146202136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2026-02-27DOI: 10.1007/s00208-026-03332-9
Matteo Carducci, Giorgio Tortone
We study the one-phase Alt-Phillips free boundary problem, focusing on the case of negative exponents . The goal of this paper is twofold. On the one hand, we prove smoothness of -regular free boundaries by reducing the problem to a class of degenerate quasilinear PDEs, for which we establish Schauder estimates. Such a method provides a unified proof of the smoothness for general exponents. On the other hand, by exploiting the higher regularity of solutions, we derive a new stability condition for the Alt-Phillips problem in the negative exponent regime, ruling out the existence of nontrivial axially symmetric stable cones in low dimensions. Finally, we provide a variational criterion for the stability of cones in the Alt-Phillips problem, which recovers the one for minimal surfaces in the singular limit as .
{"title":"Smoothness and stability in the Alt-Phillips problem.","authors":"Matteo Carducci, Giorgio Tortone","doi":"10.1007/s00208-026-03332-9","DOIUrl":"https://doi.org/10.1007/s00208-026-03332-9","url":null,"abstract":"<p><p>We study the one-phase Alt-Phillips free boundary problem, focusing on the case of negative exponents <math><mrow><mi>γ</mi> <mo>∈</mo> <mo>(</mo> <mo>-</mo> <mn>2</mn> <mo>,</mo> <mn>0</mn> <mo>)</mo></mrow> </math> . The goal of this paper is twofold. On the one hand, we prove smoothness of <math><msup><mi>C</mi> <mrow><mn>1</mn> <mo>,</mo> <mi>α</mi></mrow> </msup> </math> -regular free boundaries by reducing the problem to a class of degenerate quasilinear PDEs, for which we establish Schauder estimates. Such a method provides a unified proof of the smoothness for general exponents. On the other hand, by exploiting the higher regularity of solutions, we derive a new stability condition for the Alt-Phillips problem in the negative exponent regime, ruling out the existence of nontrivial axially symmetric stable cones in low dimensions. Finally, we provide a variational criterion for the stability of cones in the Alt-Phillips problem, which recovers the one for minimal surfaces in the singular limit as <math><mrow><mi>γ</mi> <mo>→</mo> <mo>-</mo> <mn>2</mn></mrow> </math> .</p>","PeriodicalId":18304,"journal":{"name":"Mathematische Annalen","volume":"394 3","pages":"75"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12948896/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147326600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2026-02-18DOI: 10.1007/s00208-026-03355-2
Igor Balla, Lianna Hambardzumyan, István Tomon
We prove that Boolean matrices with bounded -norm or bounded normalized trace norm must contain a linear-sized all-ones or all-zeros submatrix, verifying a conjecture of Hambardzumyan, Hatami, and Hatami. We also present further structural results about Boolean matrices of bounded -norm and discuss applications in communication complexity, operator theory, spectral graph theory, and extremal combinatorics. As a key application, we establish an inverse theorem for MaxCut. A celebrated result of Edwards states that every graph G with m edges has a cut of size at least , with equality achieved by complete graphs with an odd number of vertices. To contrast this, we prove that if the MaxCut of G is at most , then G must contain a clique of size .
证明了具有有界γ 2范数或有界归一化迹范数的布尔矩阵必须包含一个线性大小的全1或全0子矩阵,验证了Hambardzumyan、Hatami和Hatami的一个猜想。我们还进一步给出了有界γ 2 -范数布尔矩阵的结构结果,并讨论了在通信复杂性、算子理论、谱图理论和极值组合学中的应用。作为一个关键的应用,我们建立了MaxCut的反定理。Edwards的一个著名结果指出,每个有m条边的图G都有一个大小至少为m2 + 8 m + 1 - 18的切面,具有奇数个顶点的完全图可以达到相等。为了对比这一点,我们证明如果G的MaxCut不超过2m + O (m),那么G必须包含一个大小为Ω (m)的团。
{"title":"Factorization norms and an inverse theorem for MaxCut.","authors":"Igor Balla, Lianna Hambardzumyan, István Tomon","doi":"10.1007/s00208-026-03355-2","DOIUrl":"https://doi.org/10.1007/s00208-026-03355-2","url":null,"abstract":"<p><p>We prove that Boolean matrices with bounded <math><msub><mi>γ</mi> <mn>2</mn></msub> </math> -norm or bounded normalized trace norm must contain a linear-sized all-ones or all-zeros submatrix, verifying a conjecture of Hambardzumyan, Hatami, and Hatami. We also present further structural results about Boolean matrices of bounded <math><msub><mi>γ</mi> <mn>2</mn></msub> </math> -norm and discuss applications in communication complexity, operator theory, spectral graph theory, and extremal combinatorics. As a key application, we establish an inverse theorem for MaxCut. A celebrated result of Edwards states that every graph <i>G</i> with <i>m</i> edges has a cut of size at least <math> <mrow><mfrac><mi>m</mi> <mn>2</mn></mfrac> <mo>+</mo> <mfrac> <mrow> <msqrt><mrow><mn>8</mn> <mi>m</mi> <mo>+</mo> <mn>1</mn></mrow> </msqrt> <mo>-</mo> <mn>1</mn></mrow> <mn>8</mn></mfrac> </mrow> </math> , with equality achieved by complete graphs with an odd number of vertices. To contrast this, we prove that if the MaxCut of <i>G</i> is at most <math> <mrow><mfrac><mi>m</mi> <mn>2</mn></mfrac> <mo>+</mo> <mi>O</mi> <mrow><mo>(</mo> <msqrt><mi>m</mi></msqrt> <mo>)</mo></mrow> </mrow> </math> , then <i>G</i> must contain a clique of size <math><mrow><mi>Ω</mi> <mo>(</mo> <msqrt><mi>m</mi></msqrt> <mo>)</mo></mrow> </math> .</p>","PeriodicalId":18304,"journal":{"name":"Mathematische Annalen","volume":"394 3","pages":"52"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12916507/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147271371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2026-03-14DOI: 10.1007/s00208-026-03418-4
Nitin Kumar Chidambaram, Maciej Dołęga, Kento Osuga
We prove that single G-weighted -Hurwitz numbers with internal faces are computed by refined topological recursion on a rational spectral curve, for certain rational weights G. Consequently, the -Hurwitz generating function analytically continues to a rational curve. In particular, our results cover the cases of -monotone Hurwitz numbers, and the enumeration of maps and bipartite maps (with internal faces) on non-oriented surfaces. As an application, we prove that the correlators of the Gaussian, Jacobi and Laguerre -ensembles are computed by refined topological recursion.
{"title":"<ArticleTitle xmlns:ns0=\"http://www.w3.org/1998/Math/MathML\"><ns0:math><ns0:mi>b</ns0:mi></ns0:math> -Hurwitz numbers from refined topological recursion.","authors":"Nitin Kumar Chidambaram, Maciej Dołęga, Kento Osuga","doi":"10.1007/s00208-026-03418-4","DOIUrl":"https://doi.org/10.1007/s00208-026-03418-4","url":null,"abstract":"<p><p>We prove that single <i>G</i>-weighted <math><mi>b</mi></math> -Hurwitz numbers with internal faces are computed by refined topological recursion on a rational spectral curve, for certain rational weights <i>G</i>. Consequently, the <math><mi>b</mi></math> -Hurwitz generating function analytically continues to a rational curve. In particular, our results cover the cases of <math><mi>b</mi></math> -monotone Hurwitz numbers, and the enumeration of maps and bipartite maps (with internal faces) on non-oriented surfaces. As an application, we prove that the correlators of the Gaussian, Jacobi and Laguerre <math><mi>β</mi></math> -ensembles are computed by refined topological recursion.</p>","PeriodicalId":18304,"journal":{"name":"Mathematische Annalen","volume":"394 4","pages":"103"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12988905/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147468317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2026-02-13DOI: 10.1007/s00208-026-03372-1
Ignacio Barros, Pietro Beri, Laure Flapan, Brandon Williams
We give a general formula for generators of the NL cone on an orthogonal modular variety. This is the cone of effective divisors linearly equivalent to an effective linear combination of irreducible components of Noether-Lefschetz divisors. We apply this to describe, in terms of minimal generators, the NL cone of various moduli spaces of geometric origin such as those of polarized K3 surfaces, cubic fourfolds, and hyperkähler manifolds. Additionally, we establish uniruledness for many moduli spaces of primitively polarized hyperkähler manifolds of and -type. Finally, in analogy with the case of K3 surfaces of degree 2, we show that any family of polarized -type hyperkähler manifolds with divisibility 2 and polarization degree 2 over a projective base is isotrivial.
{"title":"Cones of Noether-Lefschetz divisors and moduli spaces of hyperkähler manifolds.","authors":"Ignacio Barros, Pietro Beri, Laure Flapan, Brandon Williams","doi":"10.1007/s00208-026-03372-1","DOIUrl":"10.1007/s00208-026-03372-1","url":null,"abstract":"<p><p>We give a general formula for generators of the NL cone on an orthogonal modular variety. This is the cone of effective divisors linearly equivalent to an effective linear combination of irreducible components of Noether-Lefschetz divisors. We apply this to describe, in terms of minimal generators, the NL cone of various moduli spaces of geometric origin such as those of polarized K3 surfaces, cubic fourfolds, and hyperkähler manifolds. Additionally, we establish uniruledness for many moduli spaces of primitively polarized hyperkähler manifolds of <math><mtext>OG6</mtext></math> and <math><msub><mtext>Kum</mtext> <mi>n</mi></msub> </math> -type. Finally, in analogy with the case of K3 surfaces of degree 2, we show that any family of polarized <math><msub><mtext>Kum</mtext> <mn>2</mn></msub> </math> -type hyperkähler manifolds with divisibility 2 and polarization degree 2 over a projective base is isotrivial.</p>","PeriodicalId":18304,"journal":{"name":"Mathematische Annalen","volume":"394 2","pages":"27"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12904891/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146202156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2026-02-15DOI: 10.1007/s00208-026-03406-8
Alessandro Cucinotta, Andrea Mondino
We consider manifolds with almost non-negative Ricci curvature and strictly positive integral lower bounds on the sum of the lowest k eigenvalues of the Ricci tensor. If is a Riemannian manifold satisfying such curvature bounds for , then we show that M is contained in a neighbourhood of controlled width of an isometrically embedded 1-dimensional sub-manifold. From this, we deduce several metric and topological consequences: M has at most linear volume growth and at most two ends, it has bounded 1-Urysohn width, the first Betti number of M is bounded above by 1, and there is precise information on elements of infinite order in . If is a Riemannian manifold satisfying such bounds for , then we show that M has at most -dimensional behavior at large scales. If , so that the integral lower bound is on the scalar curvature, assuming in addition that the -Ricci curvature is non-negative, we prove that the dimension drop at large scales improves to . From the above results we deduce topological restrictions, such as upper bounds on the first Betti number.
我们考虑具有几乎非负里奇曲率和里奇张量的最低k个特征值和的严格正积分下界的流形。如果(M n, g)是满足k = 2的曲率界的黎曼流形,那么我们证明M包含在等距嵌入的1维子流形的控制宽度的邻域中。由此,我们推导出几个度量和拓扑结果:M的体积最大为线性增长,最多有两个端点,它有1- urysohn宽度的边界,M的第一个Betti数的边界在1以上,并且π 1 (M)中存在无限阶元素的精确信息。如果(M n, g)是一个黎曼流形,在k≥2时满足这样的界,那么我们证明M在大尺度上最多有(k - 1)维的行为。如果k = n = dim (M),使得积分下界在标量曲率上,另外假设(n- 2) - ricci曲率非负,证明了在大尺度上的维降提高到n- 2。根据上述结果,我们推导出拓扑限制,如第一Betti数的上界。
{"title":"<ArticleTitle xmlns:ns0=\"http://www.w3.org/1998/Math/MathML\">On manifolds with almost non-negative Ricci curvature and integrally-positive <ns0:math><ns0:msup><ns0:mi>k</ns0:mi> <ns0:mrow><ns0:mi>th</ns0:mi></ns0:mrow> </ns0:msup> </ns0:math> -scalar curvature.","authors":"Alessandro Cucinotta, Andrea Mondino","doi":"10.1007/s00208-026-03406-8","DOIUrl":"https://doi.org/10.1007/s00208-026-03406-8","url":null,"abstract":"<p><p>We consider manifolds with almost non-negative Ricci curvature and strictly positive integral lower bounds on the sum of the lowest <i>k</i> eigenvalues of the Ricci tensor. If <math><mrow><mo>(</mo> <msup><mi>M</mi> <mi>n</mi></msup> <mo>,</mo> <mi>g</mi> <mo>)</mo></mrow> </math> is a Riemannian manifold satisfying such curvature bounds for <math><mrow><mi>k</mi> <mo>=</mo> <mn>2</mn></mrow> </math> , then we show that <i>M</i> is contained in a neighbourhood of controlled width of an isometrically embedded 1-dimensional sub-manifold. From this, we deduce several metric and topological consequences: <i>M</i> has at most linear volume growth and at most two ends, it has bounded 1-Urysohn width, the first Betti number of <i>M</i> is bounded above by 1, and there is precise information on elements of infinite order in <math> <mrow><msub><mi>π</mi> <mn>1</mn></msub> <mrow><mo>(</mo> <mi>M</mi> <mo>)</mo></mrow> </mrow> </math> . If <math><mrow><mo>(</mo> <msup><mi>M</mi> <mi>n</mi></msup> <mo>,</mo> <mi>g</mi> <mo>)</mo></mrow> </math> is a Riemannian manifold satisfying such bounds for <math><mrow><mi>k</mi> <mo>≥</mo> <mn>2</mn></mrow> </math> , then we show that <i>M</i> has at most <math><mrow><mo>(</mo> <mi>k</mi> <mo>-</mo> <mn>1</mn> <mo>)</mo></mrow> </math> -dimensional behavior at large scales. If <math><mrow><mi>k</mi> <mo>=</mo> <mi>n</mi> <mo>=</mo> <mtext>dim</mtext> <mo>(</mo> <mi>M</mi> <mo>)</mo></mrow> </math> , so that the integral lower bound is on the scalar curvature, assuming in addition that the <math><mrow><mo>(</mo> <mi>n</mi> <mo>-</mo> <mn>2</mn> <mo>)</mo></mrow> </math> -Ricci curvature is non-negative, we prove that the dimension drop at large scales improves to <math><mrow><mi>n</mi> <mo>-</mo> <mn>2</mn></mrow> </math> . From the above results we deduce topological restrictions, such as upper bounds on the first Betti number.</p>","PeriodicalId":18304,"journal":{"name":"Mathematische Annalen","volume":"394 2","pages":"49"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12907273/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146213694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2026-03-19DOI: 10.1007/s00208-026-03340-9
Alexandra Florea, Matilde Lalín, Amita Malik, Anurag Sahay
We study the shifted convolution problem for the divisor function in function fields in the large degree limit, that is, the average value of where f runs over monic polynomials in of a given degree, and h is a given monic polynomial. We prove an asymptotic formula in the range . We also consider mixed correlations and self-correlations of , the convolution of 1 with a Dirichlet character mod , where is a monic irreducible polynomial, proving asymptotic formulae in various ranges. This includes the case of quadratic characters, which yields results about correlations of norm-counting functions of quadratic extensions of . A novel feature of our work is a Voronoi summation formula (equivalently, a functional equation for the Estermann function) in which was not previously available.
{"title":"The shifted convolution problem in function fields.","authors":"Alexandra Florea, Matilde Lalín, Amita Malik, Anurag Sahay","doi":"10.1007/s00208-026-03340-9","DOIUrl":"https://doi.org/10.1007/s00208-026-03340-9","url":null,"abstract":"<p><p>We study the shifted convolution problem for the divisor function in function fields in the large degree limit, that is, the average value of <math><mrow><mi>d</mi> <mo>(</mo> <mi>f</mi> <mo>)</mo> <mi>d</mi> <mo>(</mo> <mi>f</mi> <mo>+</mo> <mi>h</mi> <mo>)</mo></mrow> </math> where <i>f</i> runs over monic polynomials in <math> <mrow><msub><mi>F</mi> <mi>q</mi></msub> <mrow><mo>[</mo> <mi>T</mi> <mo>]</mo></mrow> </mrow> </math> of a given degree, and <i>h</i> is a given monic polynomial. We prove an asymptotic formula in the range <math><mrow><mo>deg</mo> <mo>(</mo> <mi>h</mi> <mo>)</mo> <mo><</mo> <mo>(</mo> <mn>2</mn> <mo>-</mo> <mi>ϵ</mi> <mo>)</mo> <mo>deg</mo> <mo>(</mo> <mi>f</mi> <mo>)</mo></mrow> </math> . We also consider mixed correlations and self-correlations of <math> <mrow><msub><mi>r</mi> <mi>χ</mi></msub> <mo>=</mo> <mn>1</mn> <mo>⋆</mo> <mi>χ</mi></mrow> </math> , the convolution of 1 with a Dirichlet character mod <math><mi>ℓ</mi></math> , where <math><mi>ℓ</mi></math> is a monic irreducible polynomial, proving asymptotic formulae in various ranges. This includes the case of quadratic characters, which yields results about correlations of norm-counting functions of quadratic extensions of <math> <mrow><msub><mi>F</mi> <mi>q</mi></msub> <mrow><mo>[</mo> <mi>T</mi> <mo>]</mo></mrow> </mrow> </math> . A novel feature of our work is a Voronoi summation formula (equivalently, a functional equation for the Estermann function) in <math> <mrow><msub><mi>F</mi> <mi>q</mi></msub> <mrow><mo>[</mo> <mi>T</mi> <mo>]</mo></mrow> </mrow> </math> which was not previously available.</p>","PeriodicalId":18304,"journal":{"name":"Mathematische Annalen","volume":"395 1","pages":"6"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12999764/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147499370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}