{"title":"Solving the index problem for (curved) Bernstein–Gelfand–Gelfand sequences","authors":"Magnus Goffeng","doi":"10.1007/s10455-026-10062-3","DOIUrl":null,"url":null,"abstract":"<div><p>We study the index theory of curved Bernstein–Gelfand–Gelfand (BGG) sequences in parabolic geometry and their role in <i>K</i>-homology and noncommutative geometry. The BGG-sequences fit into <i>K</i>-homology, and we solve their index problem. We provide a condition for when the BGG-complex on the flat parabolic geometry <i>G</i>/<i>P</i> of a semisimple Lie group <i>G</i> fits into <i>G</i>-equivariant <i>K</i>-homology by means of Heisenberg calculus. For higher rank Lie groups, we prove a no-go theorem showing that the approach fails.</p></div>","PeriodicalId":8268,"journal":{"name":"Annals of Global Analysis and Geometry","volume":"70 4","pages":""},"PeriodicalIF":0.8000,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10455-026-10062-3.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Annals of Global Analysis and Geometry","FirstCategoryId":"100","ListUrlMain":"https://link.springer.com/article/10.1007/s10455-026-10062-3","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
We study the index theory of curved Bernstein–Gelfand–Gelfand (BGG) sequences in parabolic geometry and their role in K-homology and noncommutative geometry. The BGG-sequences fit into K-homology, and we solve their index problem. We provide a condition for when the BGG-complex on the flat parabolic geometry G/P of a semisimple Lie group G fits into G-equivariant K-homology by means of Heisenberg calculus. For higher rank Lie groups, we prove a no-go theorem showing that the approach fails.
期刊介绍:
This journal examines global problems of geometry and analysis as well as the interactions between these fields and their application to problems of theoretical physics. It contributes to an enlargement of the international exchange of research results in the field.
The areas covered in Annals of Global Analysis and Geometry include: global analysis, differential geometry, complex manifolds and related results from complex analysis and algebraic geometry, Lie groups, Lie transformation groups and harmonic analysis, variational calculus, applications of differential geometry and global analysis to problems of theoretical physics.