{"title":"The Liouville current of holomorphic quadratic differential metrics","authors":"Jiajun Shi","doi":"10.1007/s10711-024-00928-w","DOIUrl":"https://doi.org/10.1007/s10711-024-00928-w","url":null,"abstract":"<p>In this paper we study the Liouville current of flat cone metrics coming from a holomorphic quadratic differential. Anja Bankovic and Christopher J. Leininger proved in Bankovic and Leininger (Trans Am Math Soc 370:1867–1884, 2018) that for a fixed closed surface, there is an injection map from the space of flat cone metrics to the space of geodesic currents. We manage to show that metrics coming from holomorphic quadratic differentials can be distinguished from other flat metrics by just looking at the geodesic currents. The key idea is to analyze the support of Liouville current, which is a topological invariant independent of the metric, and get information about cone angles and holonomy. The holonomy part involves some subtlety of relationship between singular foliation and geodesic lamination. We also obtain a new proof of a classical result that almost all simple geodesics of a quadratic differential metric will be dense in the surface. Furthermore, for other flat cone metrics, there is no simple dense geodesic.</p>","PeriodicalId":55103,"journal":{"name":"Geometriae Dedicata","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140884557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An extension of the Thurston metric to projective filling currents","authors":"Jenya Sapir","doi":"10.1007/s10711-024-00914-2","DOIUrl":"https://doi.org/10.1007/s10711-024-00914-2","url":null,"abstract":"<p>We study the geometry of the space of projectivized filling geodesic currents <span>(mathbb {P}mathcal {C}_{fill}(S))</span>. Bonahon showed that Teichmüller space, <span>(mathcal {T}(S))</span> embeds into <span>(mathbb {P}mathcal {C}_{fill}(S))</span>. We extend the symmetrized Thurston metric from <span>(mathcal {T}(S))</span> to the entire (projectivized) space of filling currents, and we show that <span>(mathcal {T}(S))</span> is isometrically embedded into the bigger space. Moreover, we show that there is no quasi-isometric projection back down to <span>(mathcal {T}(S))</span>. Lastly, we study the geometry of a length-minimizing projection from <span>(mathbb {P}mathcal {C}_{fill}(S))</span> to <span>(mathcal {T}(S))</span> defined previously by Hensel and the author.</p>","PeriodicalId":55103,"journal":{"name":"Geometriae Dedicata","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140884251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Temperedness of locally symmetric spaces: the product case","authors":"Tobias Weich, Lasse L. Wolf","doi":"10.1007/s10711-024-00904-4","DOIUrl":"https://doi.org/10.1007/s10711-024-00904-4","url":null,"abstract":"<p>Let <span>(X=X_1times X_2)</span> be a product of two rank one symmetric spaces of non-compact type and <span>(Gamma )</span> a torsion-free discrete subgroup in <span>(G_1times G_2)</span>. We show that the spectrum of <span>(Gamma backslash (X_1times X_2))</span> is related to the asymptotic growth of <span>(Gamma )</span> in the two directions defined by the two factors. We obtain that <span>(L^2(Gamma backslash (G_1 times G_2)))</span> is tempered for a large class of <span>(Gamma )</span>.\u0000</p>","PeriodicalId":55103,"journal":{"name":"Geometriae Dedicata","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140884250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Minimality and unique ergodicity of Veech 1969 type interval exchange transformations","authors":"Sébastien Ferenczi, Pascal Hubert","doi":"10.1007/s10711-024-00888-1","DOIUrl":"https://doi.org/10.1007/s10711-024-00888-1","url":null,"abstract":"<p>We give conditions for minimality of <span>({mathbb {Z}}/N{mathbb {Z}})</span> extensions of a rotation of angle <span>(alpha )</span> with one marked point, solving the problem for any prime <i>N</i>: for <span>(N=2)</span>, these correspond to the Veech 1969 examples, for which a necessary and sufficient condition was not known yet. We provide also a word combinatorial criterion of minimality valid for general interval exchange transformations, which applies to <span>({mathbb {Z}}/N{mathbb {Z}})</span> extensions of any interval exchange transformation with any number of marked points. Then we give a condition for unique ergodicity of these extensions when the initial interval exchange transformation is linearly recurrent and there are one or two marked points.\u0000</p>","PeriodicalId":55103,"journal":{"name":"Geometriae Dedicata","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140884252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Distribution of periodic orbits in the homology group of a knot complement","authors":"Solly Coles, Richard Sharp","doi":"10.1007/s10711-024-00927-x","DOIUrl":"https://doi.org/10.1007/s10711-024-00927-x","url":null,"abstract":"<p>Consider a transitive Anosov flow on a closed 3-manifold. After removing a finite set of null-homologous periodic orbits, we study the distribution of the remaining periodic orbits in the homology of the knot complement.\u0000</p>","PeriodicalId":55103,"journal":{"name":"Geometriae Dedicata","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140839802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Decomposition complexity growth of finitely generated groups","authors":"Trevor Davila","doi":"10.1007/s10711-024-00924-0","DOIUrl":"https://doi.org/10.1007/s10711-024-00924-0","url":null,"abstract":"<p>Finite decomposition complexity and asymptotic dimension growth are two generalizations of M. Gromov’s asymptotic dimension which can be used to prove property A for large classes of finitely generated groups of infinite asymptotic dimension. In this paper, we introduce the notion of decomposition complexity growth, which is a quasi-isometry invariant generalizing both finite decomposition complexity and dimension growth. We show that subexponential decomposition complexity growth implies property A, and is preserved by certain group and metric constructions.</p>","PeriodicalId":55103,"journal":{"name":"Geometriae Dedicata","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140839893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Scalar curvature along the Ricci flow","authors":"Yi Li","doi":"10.1007/s10711-024-00913-3","DOIUrl":"https://doi.org/10.1007/s10711-024-00913-3","url":null,"abstract":"<p>In this note, we prove a well-known conjecture on the Ricci flow under a curvature condition, which is a pinching between the Ricci and Weyl tensors divided by suitably translated scalar curvature, motivated by Cao’s result (Commun Anal Geom 19(5):975–990, 2011).\u0000</p>","PeriodicalId":55103,"journal":{"name":"Geometriae Dedicata","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140578049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On bounded paradoxical sets and Lie groups","authors":"Grzegorz Tomkowicz","doi":"10.1007/s10711-024-00923-1","DOIUrl":"https://doi.org/10.1007/s10711-024-00923-1","url":null,"abstract":"<p>We will prove that any non-empty open set in every complete connected metric space (<i>X</i>, <i>d</i>), where balls have compact closures, contains a paradoxical (uncountable) set relative to a non-supramenable connected Lie group that acts continuously and transitively on <i>X</i>.</p>","PeriodicalId":55103,"journal":{"name":"Geometriae Dedicata","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140577829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Trisections obtained by trivially regluing surface-knots","authors":"Tsukasa Isoshima","doi":"10.1007/s10711-024-00919-x","DOIUrl":"https://doi.org/10.1007/s10711-024-00919-x","url":null,"abstract":"<p>Let <i>S</i> be a <span>(P^2)</span>-knot which is the connected sum of a 2-knot with normal Euler number 0 and an unknotted <span>(P^2)</span>-knot with normal Euler number <span>({pm }{2})</span> in a closed 4-manifold <i>X</i> with trisection <span>(T_{X})</span>. Then, we show that the trisection of <i>X</i> obtained by the trivial gluing of relative trisections of <span>(overline{nu (S)})</span> and <span>(X-nu (S))</span> is diffeomorphic to a stabilization of <span>(T_{X})</span>. It should be noted that this result is not obvious since boundary-stabilizations introduced by Kim and Miller are used to construct a relative trisection of <span>(X-nu (S))</span>. As a corollary, if <span>(X=S^4)</span> and <span>(T_X)</span> was the genus 0 trisection of <span>(S^4)</span>, the resulting trisection is diffeomorphic to a stabilization of the genus 0 trisection of <span>(S^4)</span>. This result is related to the conjecture that is a 4-dimensional analogue of Waldhausen’s theorem on Heegaard splittings.</p>","PeriodicalId":55103,"journal":{"name":"Geometriae Dedicata","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140577837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Betti numbers of nearly $$G_2$$ and nearly Kähler 6-manifolds with Weyl curvature bounds","authors":"Anton Iliashenko","doi":"10.1007/s10711-024-00920-4","DOIUrl":"https://doi.org/10.1007/s10711-024-00920-4","url":null,"abstract":"<p>In this paper we use the Weitzenböck formulas to get information about the Betti numbers of compact nearly <span>(G_2)</span> and compact nearly Kähler 6-manifolds. First, we establish estimates on two curvature-type self adjoint operators on particular spaces assuming bounds on the sectional curvature. Then using the Weitzenböck formulas on harmonic forms, we get results of the form: if certain lower bounds hold for these curvature operators then certain Betti numbers are zero. Finally, we combine both steps above to get sufficient conditions of vanishing of certain Betti numbers based on the bounds on the sectional curvature.\u0000</p>","PeriodicalId":55103,"journal":{"name":"Geometriae Dedicata","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140578032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}