{"title":"Bredon motivic cohomology of the real numbers","authors":"Bill Deng, Mircea Voineagu","doi":"10.1016/j.jpaa.2025.108016","DOIUrl":null,"url":null,"abstract":"<div><div>Over the real numbers with <span><math><mi>Z</mi><mo>/</mo><mn>2</mn></math></span>-coefficients, we compute the <span><math><msub><mrow><mi>C</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>-equivariant Borel motivic cohomology ring, the Bredon motivic cohomology groups and prove that the Bredon motivic cohomology ring of real numbers is a proper subring in the <span><math><mi>R</mi><mi>O</mi><mo>(</mo><msub><mrow><mi>C</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>×</mo><msub><mrow><mi>C</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>)</mo></math></span>-graded Bredon cohomology ring of a point.</div><div>This generalizes Voevodsky's computation of the motivic cohomology ring of the real numbers to the <span><math><msub><mrow><mi>C</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>-equivariant setting. These computations are extended afterwards to any real closed field.</div></div>","PeriodicalId":54770,"journal":{"name":"Journal of Pure and Applied Algebra","volume":"229 9","pages":"Article 108016"},"PeriodicalIF":0.7000,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Pure and Applied Algebra","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022404925001550","RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Over the real numbers with -coefficients, we compute the -equivariant Borel motivic cohomology ring, the Bredon motivic cohomology groups and prove that the Bredon motivic cohomology ring of real numbers is a proper subring in the -graded Bredon cohomology ring of a point.
This generalizes Voevodsky's computation of the motivic cohomology ring of the real numbers to the -equivariant setting. These computations are extended afterwards to any real closed field.
期刊介绍:
The Journal of Pure and Applied Algebra concentrates on that part of algebra likely to be of general mathematical interest: algebraic results with immediate applications, and the development of algebraic theories of sufficiently general relevance to allow for future applications.