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Projection formula

From Wikipedia, the free encyclopedia

In algebraic geometry, the projection formula states the following:[1][2]

For a morphism of ringed spaces, an -module and a locally free -module of finite rank, the natural maps of sheaves

are isomorphisms.

There is yet another projection formula in the setting of étale cohomology.

See also

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References

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  1. ^ Hartshorne, Robin (1977), Algebraic Geometry, Graduate Texts in Mathematics, vol. 52, New York: Springer-Verlag, ISBN 978-0-387-90244-9, MR 0463157, Ch. III, Exercise 8.3}}
  2. ^ Vakil, Ravi (2007–2008), Foundations of algebraic geometry class 38 (PDF), Stanford University