Mathematische Zeitschrift

, Volume 236, Issue 2, pp 351–382 | Cite as

Triangular Witt groups Part II: From usual to derived

  • Paul Balmer
Original article

Abstract. We establish that the derived Witt group is isomorphic to the usual Witt group when 2 is invertible. This key result opens the Ali Baba's cave of triangular Witt groups, linking the abstract results of Part I to classical questions for the usual Witt group. For commercial purposes, we survey the future applications of triangular Witt groups in the introduction. We also establish a connection between odd-indexed Witt groups and formations. Finally, we prove that over a commutative local ring in which 2 is a unit, the shifted derived Witt groups are all zero but the usual one.

Mathematics Subject Classification (1991): 11E81, 18E30, 19G12 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • Paul Balmer
    • 1
  1. 1.Department of Mathematics, Middlesex College, University of Western Ontario, London, ON N6A 5B7, Canada (e-mail: CA

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