{"title":"Degenerations of \n \n k\n $k$\n -positive surface group representations","authors":"Jonas Beyrer, Beatrice Pozzetti","doi":"10.1112/topo.12352","DOIUrl":null,"url":null,"abstract":"<p>We introduce <span></span><math>\n <semantics>\n <mi>k</mi>\n <annotation>$k$</annotation>\n </semantics></math>-<i>positive representations</i>, a large class of <span></span><math>\n <semantics>\n <mrow>\n <mo>{</mo>\n <mn>1</mn>\n <mo>,</mo>\n <mtext>…</mtext>\n <mo>,</mo>\n <mi>k</mi>\n <mo>}</mo>\n </mrow>\n <annotation>$\\lbrace 1,\\ldots ,k\\rbrace$</annotation>\n </semantics></math>-Anosov surface group representations into <span></span><math>\n <semantics>\n <mrow>\n <mi>PGL</mi>\n <mo>(</mo>\n <mi>E</mi>\n <mo>)</mo>\n </mrow>\n <annotation>$\\mathsf {PGL}(E)$</annotation>\n </semantics></math> that share many features with Hitchin representations, and we study their degenerations: unless they are Hitchin, they can be deformed to non-discrete representations, but any limit is at least <span></span><math>\n <semantics>\n <mrow>\n <mo>(</mo>\n <mi>k</mi>\n <mo>−</mo>\n <mn>3</mn>\n <mo>)</mo>\n </mrow>\n <annotation>$(k-3)$</annotation>\n </semantics></math>-positive and irreducible limits are <span></span><math>\n <semantics>\n <mrow>\n <mo>(</mo>\n <mi>k</mi>\n <mo>−</mo>\n <mn>1</mn>\n <mo>)</mo>\n </mrow>\n <annotation>$(k-1)$</annotation>\n </semantics></math>-positive. A major ingredient, of independent interest, is a general limit theorem for positively ratioed representations.</p>","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1112/topo.12352","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
We introduce -positive representations, a large class of -Anosov surface group representations into that share many features with Hitchin representations, and we study their degenerations: unless they are Hitchin, they can be deformed to non-discrete representations, but any limit is at least -positive and irreducible limits are -positive. A major ingredient, of independent interest, is a general limit theorem for positively ratioed representations.