Depth and Perversity

  • Lê Dũng Tráng
Conference paper


In the seminar on Algebraic Geometry (SGA 2) concerning the theorems of Lefschetz type ([G]) A. Grothendieck showed that the notion of depth introduced for rings and modules could be understood through the vanishing of adequate cohomologies. The topological counterpart of this notion of depth in homotopy and rational cohomology are related to the classical theorem of Lefschetz on hyperplane sections. The analogy between topology and commutative algebra led A. Grothendieck to formulate several conjectures which appear to be true (see [H-L]).


Homotopy Type Good Neighbourhood Constructible Complex Complex Link Constant Sheaf 
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Copyright information

© Springer-Verlag Tokyo 1991

Authors and Affiliations

  • Lê Dũng Tráng
    • 1
  1. 1.Department of MathematicsNortheastern UniversityBostonUSA

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