{"title":"The low dimensional homology groups of the elementary group of degree two","authors":"Behrooz Mirzaii, Elvis Torres Pérez","doi":"10.1007/s40062-026-00401-3","DOIUrl":null,"url":null,"abstract":"<div><p>In this article, we study the first, second, and third homology groups of the elementary group <span>\\({\\textrm{E}}_2(A)\\)</span>, where <i>A</i> is a commutative ring. In particular, we establish a refined Bloch–Wigner type exact sequence over a semilocal ring (subject to mild restrictions on its residue fields) in which either <span>\\(-1 \\in ({A^\\times })^2\\)</span> or <span>\\(|{A^\\times }/({A^\\times })^2| \\le 4\\)</span>.\n</p></div>","PeriodicalId":49034,"journal":{"name":"Journal of Homotopy and Related Structures","volume":"21 3","pages":"509 - 535"},"PeriodicalIF":0.5000,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Homotopy and Related Structures","FirstCategoryId":"100","ListUrlMain":"https://link.springer.com/article/10.1007/s40062-026-00401-3","RegionNum":4,"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
In this article, we study the first, second, and third homology groups of the elementary group \({\textrm{E}}_2(A)\), where A is a commutative ring. In particular, we establish a refined Bloch–Wigner type exact sequence over a semilocal ring (subject to mild restrictions on its residue fields) in which either \(-1 \in ({A^\times })^2\) or \(|{A^\times }/({A^\times })^2| \le 4\).
期刊介绍:
Journal of Homotopy and Related Structures (JHRS) is a fully refereed international journal dealing with homotopy and related structures of mathematical and physical sciences.
Journal of Homotopy and Related Structures is intended to publish papers on
Homotopy in the broad sense and its related areas like Homological and homotopical algebra, K-theory, topology of manifolds, geometric and categorical structures, homology theories, topological groups and algebras, stable homotopy theory, group actions, algebraic varieties, category theory, cobordism theory, controlled topology, noncommutative geometry, motivic cohomology, differential topology, algebraic geometry.