Journal of Algebraic Combinatorics

, Volume 16, Issue 2, pp 111–150 | Cite as

More on Geometries of the Fischer Group Fi22

  • A.A. Ivanov
  • C. Wiedorn


We give a new, purely combinatorial characterization of geometries \(\varepsilon \) with diagram Open image in new window identifying each under some “natural” conditions—but not assuming any group action a priori—with one of the two geometries \(\mathcal{E}(Fi_{22} )\) and \(\mathcal{E}(3 \cdot Fi_{22} )\) related to the Fischer 3-transposition group Fi22 and its non-split central extension 3 · Fi22, respectively. As a by-product we improve the known characterization of the c-extended dual polar spaces for Fi22 and 3 · Fi22 and of the truncation of the c-extended 6-dimensional unitary polar space.

Fischer group diagram geometry extended building 


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Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • A.A. Ivanov
    • 1
  • C. Wiedorn
    • 2
  1. 1.Department of MathematicsImperial CollegeLondonUK
  2. 2.Department of MathematicsUniversity of BirminghamBirminghamUK

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