Journal of Topology最新文献

{"title":"A new approach to twisted homological stability with applications to congruence subgroups","authors":"Andrew Putman","doi":"10.1112/topo.12316","DOIUrl":"https://doi.org/10.1112/topo.12316","url":null,"abstract":"<p>We introduce a new method for proving twisted homological stability, and use it to prove such results for symmetric groups and general linear groups. In addition to sometimes slightly improving the stable range given by the traditional method (due to Dwyer), it is easier to adapt to nonstandard situations. As an illustration of this, we generalize to <math>\u0000 <semantics>\u0000 <msub>\u0000 <mo>GL</mo>\u0000 <mi>n</mi>\u0000 </msub>\u0000 <annotation>$operatorname{GL}_n$</annotation>\u0000 </semantics></math> of many rings <math>\u0000 <semantics>\u0000 <mi>R</mi>\u0000 <annotation>$R$</annotation>\u0000 </semantics></math> a theorem of Borel that says that passing from <math>\u0000 <semantics>\u0000 <msub>\u0000 <mo>GL</mo>\u0000 <mi>n</mi>\u0000 </msub>\u0000 <annotation>$operatorname{GL}_n$</annotation>\u0000 </semantics></math> of a number ring to a finite-index subgroup does not change the rational cohomology. Charney proved this generalization for trivial coefficients, and we extend it to twisted coefficients.</p>","PeriodicalId":56114,"journal":{"name":"Journal of Topology","volume":"16 4","pages":"1315-1388"},"PeriodicalIF":1.1,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138432408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Motivic Pontryagin classes and hyperbolic orientations","authors":"Olivier Haution","doi":"10.1112/topo.12317","DOIUrl":"https://doi.org/10.1112/topo.12317","url":null,"abstract":"<p>We introduce the notion of hyperbolic orientation of a motivic ring spectrum, which generalises the various existing notions of orientation (by the groups <math>\u0000 <semantics>\u0000 <mo>GL</mo>\u0000 <annotation>$operatorname{GL}$</annotation>\u0000 </semantics></math>, <math>\u0000 <semantics>\u0000 <msup>\u0000 <mo>SL</mo>\u0000 <mi>c</mi>\u0000 </msup>\u0000 <annotation>$operatorname{SL}^c$</annotation>\u0000 </semantics></math>, <math>\u0000 <semantics>\u0000 <mo>SL</mo>\u0000 <annotation>$operatorname{SL}$</annotation>\u0000 </semantics></math>, <math>\u0000 <semantics>\u0000 <mo>Sp</mo>\u0000 <annotation>$operatorname{Sp}$</annotation>\u0000 </semantics></math>). We show that hyperbolic orientations of <math>\u0000 <semantics>\u0000 <mi>η</mi>\u0000 <annotation>$eta$</annotation>\u0000 </semantics></math>-periodic ring spectra correspond to theories of Pontryagin classes, much in the same way that <math>\u0000 <semantics>\u0000 <mo>GL</mo>\u0000 <annotation>$operatorname{GL}$</annotation>\u0000 </semantics></math>-orientations of arbitrary ring spectra correspond to theories of Chern classes. We prove that <math>\u0000 <semantics>\u0000 <mi>η</mi>\u0000 <annotation>$eta$</annotation>\u0000 </semantics></math>-periodic hyperbolically oriented cohomology theories do not admit further characteristic classes for vector bundles, by computing the cohomology of the étale classifying space <math>\u0000 <semantics>\u0000 <msub>\u0000 <mo>BGL</mo>\u0000 <mi>n</mi>\u0000 </msub>\u0000 <annotation>$operatorname{BGL}_n$</annotation>\u0000 </semantics></math>. Finally, we construct the universal hyperbolically oriented <math>\u0000 <semantics>\u0000 <mi>η</mi>\u0000 <annotation>$eta$</annotation>\u0000 </semantics></math>-periodic commutative motivic ring spectrum, an analogue of Voevodsky's cobordism spectrum <math>\u0000 <semantics>\u0000 <mo>MGL</mo>\u0000 <annotation>$operatorname{MGL}$</annotation>\u0000 </semantics></math>.</p>","PeriodicalId":56114,"journal":{"name":"Journal of Topology","volume":"16 4","pages":"1423-1474"},"PeriodicalIF":1.1,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://londmathsoc.onlinelibrary.wiley.com/doi/epdf/10.1112/topo.12317","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138432411","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}

{"title":"On the motivic Segal conjecture","authors":"Thomas Gregersen,&nbsp;John Rognes","doi":"10.1112/topo.12311","DOIUrl":"10.1112/topo.12311","url":null,"abstract":"<p>We establish motivic versions of the theorems of Lin and Gunawardena, thereby confirming the motivic Segal conjecture for the algebraic group <math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>μ</mi>\u0000 <mi>ℓ</mi>\u0000 </msub>\u0000 <annotation>$mu _ell$</annotation>\u0000 </semantics></math> of <math>\u0000 <semantics>\u0000 <mi>ℓ</mi>\u0000 <annotation>$ell$</annotation>\u0000 </semantics></math>th roots of unity, where <math>\u0000 <semantics>\u0000 <mi>ℓ</mi>\u0000 <annotation>$ell$</annotation>\u0000 </semantics></math> is any prime. To achieve this we develop motivic Singer constructions associated to the symmetric group <math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>S</mi>\u0000 <mi>ℓ</mi>\u0000 </msub>\u0000 <annotation>$S_ell$</annotation>\u0000 </semantics></math> and to <math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>μ</mi>\u0000 <mi>ℓ</mi>\u0000 </msub>\u0000 <annotation>$mu _ell$</annotation>\u0000 </semantics></math>, and introduce a delayed limit Adams spectral sequence.</p>","PeriodicalId":56114,"journal":{"name":"Journal of Topology","volume":"16 3","pages":"1258-1313"},"PeriodicalIF":1.1,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1112/topo.12311","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45024268","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}

{"title":"Homotopy of manifolds stabilized by projective spaces","authors":"Ruizhi Huang,&nbsp;Stephen Theriault","doi":"10.1112/topo.12313","DOIUrl":"10.1112/topo.12313","url":null,"abstract":"<p>We study the homotopy of the connected sum of a manifold with a projective space, viewed as a typical way to stabilize manifolds. In particular, we show a loop homotopy decomposition of a manifold after stabilization by a projective space, and provide concrete examples. To do this, we trace the effect in homotopy theory of surgery on certain product manifolds by showing a loop homotopy decomposition after localization away from the order of the image of the classical <math>\u0000 <semantics>\u0000 <mi>J</mi>\u0000 <annotation>$J$</annotation>\u0000 </semantics></math>-homomorphism.</p>","PeriodicalId":56114,"journal":{"name":"Journal of Topology","volume":"16 3","pages":"1237-1257"},"PeriodicalIF":1.1,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1112/topo.12313","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48207005","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}

{"title":"Equivariant knots and knot Floer homology","authors":"Irving Dai,&nbsp;Abhishek Mallick,&nbsp;Matthew Stoffregen","doi":"10.1112/topo.12312","DOIUrl":"10.1112/topo.12312","url":null,"abstract":"We define several equivariant concordance invariants using knot Floer homology. We show that our invariants provide a lower bound for the equivariant slice genus and use this to give a family of strongly invertible slice knots whose equivariant slice genus grows arbitrarily large, answering a question of Boyle and Issa. We also apply our formalism to several seemingly nonequivariant questions. In particular, we show that knot Floer homology can be used to detect exotic pairs of slice disks, recovering an example due to Hayden, and extend a result due to Miller and Powell regarding stabilization distance. Our formalism suggests a possible route toward establishing the noncommutativity of the equivariant concordance group.","PeriodicalId":56114,"journal":{"name":"Journal of Topology","volume":"16 3","pages":"1167-1236"},"PeriodicalIF":1.1,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42949514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lagrangian cobordism functor in microlocal sheaf theory I","authors":"Wenyuan Li","doi":"10.1112/topo.12310","DOIUrl":"10.1112/topo.12310","url":null,"abstract":"&lt;p&gt;Let &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;Λ&lt;/mi&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$Lambda _pm$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; be Legendrian submanifolds in the cosphere bundle &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;T&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;∗&lt;/mo&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;mi&gt;∞&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$T^{*,infty }M$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. Given a Lagrangian cobordism &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;L&lt;/mi&gt;\u0000 &lt;annotation&gt;$L$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; of Legendrians from &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;Λ&lt;/mi&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$Lambda _-$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; to &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;Λ&lt;/mi&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$Lambda _+$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, we construct a functor &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;Φ&lt;/mi&gt;\u0000 &lt;mi&gt;L&lt;/mi&gt;\u0000 &lt;mo&gt;*&lt;/mo&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;mo&gt;:&lt;/mo&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;Sh&lt;/mi&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;Λ&lt;/mi&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mi&gt;c&lt;/mi&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;→&lt;/mo&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;Sh&lt;/mi&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;Λ&lt;/mi&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mi&gt;c&lt;/mi&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mo&gt;⊗&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;C&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mo&gt;*&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/m","PeriodicalId":56114,"journal":{"name":"Journal of Topology","volume":"16 3","pages":"1113-1166"},"PeriodicalIF":1.1,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1112/topo.12310","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46583482","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}

{"title":"Smoothing finite-order bilipschitz homeomorphisms of 3-manifolds","authors":"Lucien Grillet","doi":"10.1112/topo.12309","DOIUrl":"10.1112/topo.12309","url":null,"abstract":"<p>We show that, for <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>ε</mi>\u0000 <mo>=</mo>\u0000 <mfrac>\u0000 <mn>1</mn>\u0000 <mn>4000</mn>\u0000 </mfrac>\u0000 </mrow>\u0000 <annotation>$varepsilon =frac{1}{4000}$</annotation>\u0000 </semantics></math>, any action of a finite cyclic group by <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mn>1</mn>\u0000 <mo>+</mo>\u0000 <mi>ε</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$(1+varepsilon )$</annotation>\u0000 </semantics></math>-bilipschitz homeomorphisms on a closed 3-manifold is conjugated to a smooth action.</p>","PeriodicalId":56114,"journal":{"name":"Journal of Topology","volume":"16 3","pages":"1093-1112"},"PeriodicalIF":1.1,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47990972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The top homology group of the genus 3 Torelli group","authors":"Igor A. Spiridonov","doi":"10.1112/topo.12308","DOIUrl":"10.1112/topo.12308","url":null,"abstract":"&lt;p&gt;The Torelli group of a genus &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;annotation&gt;$g$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; oriented surface &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;Σ&lt;/mi&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$Sigma _g$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; is the subgroup &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;I&lt;/mi&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$mathcal {I}_g$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; of the mapping class group &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Mod&lt;/mi&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;Σ&lt;/mi&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;${rm Mod}(Sigma _g)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; consisting of all mapping classes that act trivially on &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;Σ&lt;/mi&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;mi&gt;Z&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;${rm H}_1(Sigma _g, mathbb {Z})$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. The quotient group &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Mod&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;Σ&lt;/mi&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;/&lt;/mo&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;I&lt;/mi&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;${rm Mod}(Sigma _g) / mathcal {I}_g$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; is isomorphic to the symplectic group &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Sp&lt;/mi&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;mi&gt;Z&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;${rm Sp}(2g, mathbb {Z})$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. The cohomological dimension of the group &lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;I&lt;/mi&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$mathcal {I}_g$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; equ","PeriodicalId":56114,"journal":{"name":"Journal of Topology","volume":"16 3","pages":"1048-1092"},"PeriodicalIF":1.1,"publicationDate":"2023-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43984189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamical properties of convex cocompact actions in projective space","authors":"Theodore Weisman","doi":"10.1112/topo.12307","DOIUrl":"10.1112/topo.12307","url":null,"abstract":"<p>We give a dynamical characterization of convex cocompact group actions on properly convex domains in projective space in the sense of Danciger–Guéritaud–Kassel: we show that convex cocompactness in <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>R</mi>\u0000 <msup>\u0000 <mi>P</mi>\u0000 <mi>d</mi>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$mathbb {R}mathrm{P}^d$</annotation>\u0000 </semantics></math> is equivalent to an expansion property of the group about its limit set, occurring in different Grassmannians. As an application, we give a sufficient and necessary condition for convex cocompactness for groups that are hyperbolic relative to a collection of convex cocompact subgroups. We show that convex cocompactness in this situation is equivalent to the existence of an equivariant homeomorphism from the Bowditch boundary to the quotient of the limit set of the group by the limit sets of its peripheral subgroups.</p>","PeriodicalId":56114,"journal":{"name":"Journal of Topology","volume":"16 3","pages":"990-1047"},"PeriodicalIF":1.1,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43304379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automorphisms of procongruence curve and pants complexes","authors":"Marco Boggi,&nbsp;Louis Funar","doi":"10.1112/topo.12306","DOIUrl":"10.1112/topo.12306","url":null,"abstract":"<p>In this paper we study the automorphism group of the procongruence mapping class group through its action on the associated procongruence curve and pants complexes. Our main result is a rigidity theorem for the procongruence completion of the pants complex. As an application we prove that moduli stacks of smooth algebraic curves satisfy a weak anabelian property in the procongruence setting.</p>","PeriodicalId":56114,"journal":{"name":"Journal of Topology","volume":"16 3","pages":"936-989"},"PeriodicalIF":1.1,"publicationDate":"2023-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47340177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}