Pub Date : 2022-05-17DOI: 10.1007/s00039-022-00602-x
Michael Magee, Frédéric Naud, Doron Puder
Let X be a compact connected hyperbolic surface, that is, a closed connected orientable smooth surface with a Riemannian metric of constant curvature (-1). For each (nin {mathbf {N}}), let (X_{n}) be a random degree-n cover of X sampled uniformly from all degree-n Riemannian covering spaces of X. An eigenvalue of X or (X_{n}) is an eigenvalue of the associated Laplacian operator (Delta _{X}) or (Delta _{X_{n}}). We say that an eigenvalue of (X_{n}) is new if it occurs with greater multiplicity than in X. We prove that for any (varepsilon >0), with probability tending to 1 as (nrightarrow infty ), there are no new eigenvalues of (X_{n}) below (frac{3}{16}-varepsilon ). We conjecture that the same result holds with (frac{3}{16}) replaced by (frac{1}{4}).
{"title":"A random cover of a compact hyperbolic surface has relative spectral gap $$frac{3}{16}-varepsilon $$ 3 16 - ε","authors":"Michael Magee, Frédéric Naud, Doron Puder","doi":"10.1007/s00039-022-00602-x","DOIUrl":"https://doi.org/10.1007/s00039-022-00602-x","url":null,"abstract":"<p>Let <i>X</i> be a compact connected hyperbolic surface, that is, a closed connected orientable smooth surface with a Riemannian metric of constant curvature <span>(-1)</span>. For each <span>(nin {mathbf {N}})</span>, let <span>(X_{n})</span> be a random degree-<i>n</i> cover of <i>X</i> sampled uniformly from all degree-<i>n</i> Riemannian covering spaces of <i>X</i>. An eigenvalue of <i>X</i> or <span>(X_{n})</span> is an eigenvalue of the associated Laplacian operator <span>(Delta _{X})</span> or <span>(Delta _{X_{n}})</span>. We say that an eigenvalue of <span>(X_{n})</span> is <i>new </i>if it occurs with greater multiplicity than in <i>X</i>. We prove that for any <span>(varepsilon >0)</span>, with probability tending to 1 as <span>(nrightarrow infty )</span>, there are no new eigenvalues of <span>(X_{n})</span> below <span>(frac{3}{16}-varepsilon )</span>. We conjecture that the same result holds with <span>(frac{3}{16})</span> replaced by <span>(frac{1}{4})</span>.\u0000</p>","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"18 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138516633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-01DOI: 10.1007/s00039-022-00597-5
Jonathan Tidor, H. Yu, Yufei Zhao
{"title":"Joints of Varieties","authors":"Jonathan Tidor, H. Yu, Yufei Zhao","doi":"10.1007/s00039-022-00597-5","DOIUrl":"https://doi.org/10.1007/s00039-022-00597-5","url":null,"abstract":"","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"32 1","pages":"302 - 339"},"PeriodicalIF":2.2,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51866658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-29DOI: 10.1007/s00039-022-00612-9
B. Klartag, J. Lehec
{"title":"Bourgain’s slicing problem and KLS isoperimetry up to polylog","authors":"B. Klartag, J. Lehec","doi":"10.1007/s00039-022-00612-9","DOIUrl":"https://doi.org/10.1007/s00039-022-00612-9","url":null,"abstract":"","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"32 1","pages":"1134 - 1159"},"PeriodicalIF":2.2,"publicationDate":"2022-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48594183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-28DOI: 10.1007/s00039-022-00594-8
Gang Liu, Gábor Székelyhidi
We show that non-collapsed Gromov–Hausdorff limits of polarized Kähler manifolds, with Ricci curvature bounded below, are normal projective varieties, and the metric singularities of the limit space are precisely given by a countable union of analytic subvarieties. This extends a fundamental result of Donaldson–Sun, in which 2-sided Ricci curvature bounds were assumed. As a basic ingredient we show that, under lower Ricci curvature bounds, almost Euclidean balls in Kähler manifolds admit good holomorphic coordinates. Further applications are integral bounds for the scalar curvature on balls, and a rigidity theorem for Kähler manifolds with almost Euclidean volume growth.
{"title":"Gromov–Hausdorff limits of Kähler manifolds with Ricci curvature bounded below","authors":"Gang Liu, Gábor Székelyhidi","doi":"10.1007/s00039-022-00594-8","DOIUrl":"https://doi.org/10.1007/s00039-022-00594-8","url":null,"abstract":"<p>We show that non-collapsed Gromov–Hausdorff limits of polarized Kähler manifolds, with Ricci curvature bounded below, are normal projective varieties, and the metric singularities of the limit space are precisely given by a countable union of analytic subvarieties. This extends a fundamental result of Donaldson–Sun, in which 2-sided Ricci curvature bounds were assumed. As a basic ingredient we show that, under lower Ricci curvature bounds, almost Euclidean balls in Kähler manifolds admit good holomorphic coordinates. Further applications are integral bounds for the scalar curvature on balls, and a rigidity theorem for Kähler manifolds with almost Euclidean volume growth.</p>","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"25 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138516613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-23DOI: 10.1007/s00039-022-00608-5
A. Kulikov
{"title":"Functionals with extrema at reproducing kernels","authors":"A. Kulikov","doi":"10.1007/s00039-022-00608-5","DOIUrl":"https://doi.org/10.1007/s00039-022-00608-5","url":null,"abstract":"","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"32 1","pages":"938 - 949"},"PeriodicalIF":2.2,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41623094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-17DOI: 10.1007/s00039-022-00595-7
Yunhui Wu, Yuhao Xue
{"title":"Random hyperbolic surfaces of large genus have first eigenvalues greater than 316-ϵdocumentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} begi","authors":"Yunhui Wu, Yuhao Xue","doi":"10.1007/s00039-022-00595-7","DOIUrl":"https://doi.org/10.1007/s00039-022-00595-7","url":null,"abstract":"","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"32 1","pages":"340 - 410"},"PeriodicalIF":2.2,"publicationDate":"2022-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51866560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-15DOI: 10.1007/s00039-022-00592-w
A. Bufetov, Yanqi Qiu
{"title":"The Patterson–Sullivan Reconstruction of Pluriharmonic Functions for Determinantal Point Processes on Complex Hyperbolic Spaces","authors":"A. Bufetov, Yanqi Qiu","doi":"10.1007/s00039-022-00592-w","DOIUrl":"https://doi.org/10.1007/s00039-022-00592-w","url":null,"abstract":"","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"32 1","pages":"135 - 192"},"PeriodicalIF":2.2,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48310365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-24DOI: 10.1007/s00039-023-00645-8
Siqi He
{"title":"The Branched Deformations of the Special Lagrangian Submanifolds","authors":"Siqi He","doi":"10.1007/s00039-023-00645-8","DOIUrl":"https://doi.org/10.1007/s00039-023-00645-8","url":null,"abstract":"","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"33 1","pages":"1266 - 1321"},"PeriodicalIF":2.2,"publicationDate":"2022-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45061663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}