Pub Date : 2023-10-31DOI: 10.1007/s00039-023-00653-8
Shinpei Baba
We consider the space of ordered pairs of distinct ({mathbb{C}{mathrm{P}}}^{1})-structures on Riemann surfaces (of any orientations) which have identical holonomy, so that the quasi-Fuchsian space is identified with a connected component of this space. This space holomorphically maps to the product of the Teichmüller spaces minus its diagonal.
In this paper, we prove that this mapping is a complete local branched covering map. As a corollary, we reprove Bers’ simultaneous uniformization theorem without any quasi-conformal deformation theory. Our main theorem is that the intersection of arbitrary two Poincaré holonomy varieties ((operatorname{SL}_{2}mathbb{C})-opers) is a non-empty discrete set, which is closely related to the mapping.
{"title":"Bers’ simultaneous uniformization and the intersection of Poincaré holonomy varieties","authors":"Shinpei Baba","doi":"10.1007/s00039-023-00653-8","DOIUrl":"https://doi.org/10.1007/s00039-023-00653-8","url":null,"abstract":"<p>We consider the space of ordered pairs of distinct <span>({mathbb{C}{mathrm{P}}}^{1})</span>-structures on Riemann surfaces (of any orientations) which have identical holonomy, so that the quasi-Fuchsian space is identified with a connected component of this space. This space holomorphically maps to the product of the Teichmüller spaces minus its diagonal.</p><p>In this paper, we prove that this mapping is a complete local branched covering map. As a corollary, we reprove Bers’ simultaneous uniformization theorem without any quasi-conformal deformation theory. Our main theorem is that the intersection of arbitrary two Poincaré holonomy varieties (<span>(operatorname{SL}_{2}mathbb{C})</span>-opers) is a non-empty discrete set, which is closely related to the mapping.</p>","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"25 12","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71509200","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 : 2023-10-12DOI: 10.1007/s00039-023-00652-9
Ivan Yakovlev
We find the generating function for the contributions of n-cylinder square-tiled surfaces to the Masur–Veech volume of (mathcal{H}(2g-2)). It is a bivariate generalization of the generating function for the total volumes obtained by Sauvaget via intersection theory. Our approach is, however, purely combinatorial. It relies on the study of counting functions for certain families of metric ribbon graphs. Their top-degree terms are polynomials, whose (normalized) coefficients are cardinalities of certain families of metric plane trees. These polynomials are analogues of Kontsevich polynomials that appear as part of his proof of Witten’s conjecture.
{"title":"Contribution of n-cylinder square-tiled surfaces to Masur–Veech volume of $mathcal{H}(2g-2)$","authors":"Ivan Yakovlev","doi":"10.1007/s00039-023-00652-9","DOIUrl":"https://doi.org/10.1007/s00039-023-00652-9","url":null,"abstract":"<p>We find the generating function for the contributions of <i>n</i>-cylinder square-tiled surfaces to the Masur–Veech volume of <span>(mathcal{H}(2g-2))</span>. It is a bivariate generalization of the generating function for the total volumes obtained by Sauvaget via intersection theory. Our approach is, however, purely combinatorial. It relies on the study of counting functions for certain families of metric ribbon graphs. Their top-degree terms are polynomials, whose (normalized) coefficients are cardinalities of certain families of metric plane trees. These polynomials are analogues of Kontsevich polynomials that appear as part of his proof of Witten’s conjecture.</p>","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"26 4","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71509213","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 : 2023-10-12DOI: 10.1007/s00039-023-00651-w
Friedrich Martin Schneider
We prove a concentration inequality for invariant means on topological groups, namely for such adapted to a chain of amenable topological subgroups. The result is based on an application of Azuma’s martingale inequality and provides a method for establishing extreme amenability. Building on this technique, we exhibit new examples of extremely amenable groups arising from von Neumann’s continuous geometries. Along the way, we also answer a question by Pestov on dynamical concentration in direct products of amenable topological groups.
{"title":"Concentration of invariant means and dynamics of chain stabilizers in continuous geometries","authors":"Friedrich Martin Schneider","doi":"10.1007/s00039-023-00651-w","DOIUrl":"https://doi.org/10.1007/s00039-023-00651-w","url":null,"abstract":"<p>We prove a concentration inequality for invariant means on topological groups, namely for such adapted to a chain of amenable topological subgroups. The result is based on an application of Azuma’s martingale inequality and provides a method for establishing extreme amenability. Building on this technique, we exhibit new examples of extremely amenable groups arising from von Neumann’s continuous geometries. Along the way, we also answer a question by Pestov on dynamical concentration in direct products of amenable topological groups.</p>","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"26 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71509198","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 : 2023-01-24DOI: 10.1007/s00039-023-00628-9
Hiroyasu Izeki
Let $Gamma$ be a finitely generated group equipped with a symmetric and nondegenerate probability measure $mu$ with finite second moment, and $Y$ a CAT(0) space which is either proper or of finite telescopic dimension. We show that if an isometric action of $Gamma$ on $Y$ has vanishing rate of escape with respect to $mu$ and does not fix a point in the boundary at infinity of $Y$, then there exists a flat subspace in $Y$ which is left invariant under the action of $Gamma$. In the proof of this result, an equivariant $mu$-harmonic map from $Gamma$ into $Y$ plays an important role.
{"title":"Isometric group actions with vanishing rate of escape on $$textrm{CAT}(0)$$ spaces","authors":"Hiroyasu Izeki","doi":"10.1007/s00039-023-00628-9","DOIUrl":"https://doi.org/10.1007/s00039-023-00628-9","url":null,"abstract":"Let $Gamma$ be a finitely generated group equipped with a symmetric and nondegenerate probability measure $mu$ with finite second moment, and $Y$ a CAT(0) space which is either proper or of finite telescopic dimension. We show that if an isometric action of $Gamma$ on $Y$ has vanishing rate of escape with respect to $mu$ and does not fix a point in the boundary at infinity of $Y$, then there exists a flat subspace in $Y$ which is left invariant under the action of $Gamma$. In the proof of this result, an equivariant $mu$-harmonic map from $Gamma$ into $Y$ plays an important role.","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136198725","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 : 2023-01-02DOI: 10.1007/s00039-023-00646-7
O. Solan, Y. Yifrach
{"title":"Tori Approximation of Families of Diagonally Invariant Measures","authors":"O. Solan, Y. Yifrach","doi":"10.1007/s00039-023-00646-7","DOIUrl":"https://doi.org/10.1007/s00039-023-00646-7","url":null,"abstract":"","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"33 1","pages":"1354 - 1378"},"PeriodicalIF":2.2,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47938375","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 : 2022-11-29DOI: 10.1007/s00039-022-00622-7
Yuanqing Cai, S. Friedberg, Eyal Kaplan
{"title":"Publisher Correction to: The generalized doubling method: local theory","authors":"Yuanqing Cai, S. Friedberg, Eyal Kaplan","doi":"10.1007/s00039-022-00622-7","DOIUrl":"https://doi.org/10.1007/s00039-022-00622-7","url":null,"abstract":"","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"32 1","pages":"1334 - 1334"},"PeriodicalIF":2.2,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46602211","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 : 2022-11-03DOI: 10.1007/s00039-023-00632-z
A. Avila, D. Damanik, A. Gorodetski
{"title":"The Spectrum of Schrödinger Operators with Randomly Perturbed Ergodic Potentials","authors":"A. Avila, D. Damanik, A. Gorodetski","doi":"10.1007/s00039-023-00632-z","DOIUrl":"https://doi.org/10.1007/s00039-023-00632-z","url":null,"abstract":"","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"33 1","pages":"364-375"},"PeriodicalIF":2.2,"publicationDate":"2022-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51866871","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 : 2022-10-22DOI: 10.1007/s00039-022-00620-9
Wangjian Jian, Jian Song
{"title":"Diameter estimates for long-time solutions of the Kähler–Ricci flow","authors":"Wangjian Jian, Jian Song","doi":"10.1007/s00039-022-00620-9","DOIUrl":"https://doi.org/10.1007/s00039-022-00620-9","url":null,"abstract":"","PeriodicalId":12478,"journal":{"name":"Geometric and Functional Analysis","volume":"32 1","pages":"1335 - 1356"},"PeriodicalIF":2.2,"publicationDate":"2022-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43085785","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}