1. Home
    2. Journals
    3. Proceedings – Mathematical Sciences
    4. Volume 119
    5. Issue 1

    • Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/pmsc/119/01/0009-0022

    • Keywords

       

      Hyperbolic groups; quaternion algebras; free groups; group rings; units.

    • Abstract

       

      We classify the quadratic extensions $K=\mathbb{Q}[\sqrt{d}]$ and the finite groups 𝐺 for which the group ring $\mathfrak{o}_K[G]$ of 𝐺 over the ring $\mathfrak{o}_K$ of integers of 𝐾 has the property that the group $\mathcal{U}_1(\mathfrak{o}_K[G])$ of units of augmentation 1 is hyperbolic. We also construct units in the $\mathbb{Z}$-order $\mathcal{H}(\mathfrak{o}_K)$ of the quaternion algebra $\mathcal{H}(K)=\left\frac{-1,-1}{k}(\right)$, when it is a division algebra.

    • Author Affiliations

       

      S O Juriaans1 I B S Passi2 A C Souza Filho3

      1. Instituto de Matemática e Estatística, Universidade de São Paulo (IME-USP), Caixa Postal 66281, São Paulo, CEP 05315-970, Brasil
      2. Centre for Advanced Study in Mathematics, Panjab University, Chandigarh 160 014, India
      3. Escola de Artes, Ciências e Humanidades, Universidade de São Paulo (EACH-USP), Rua Arlindo Béttio, 1000, Ermelindo Matarazzo, São Paulo, CEP 03828-000, Brasil

    • Dates

       
      Published
      February 2009
      Manuscript received
      13 December 2007
      Manuscript revised
      1 September 2008

  • Proceedings – Mathematical Sciences | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2022-2023 Indian Academy of Sciences, Bengaluru.

Contact | Site index