Étale cohomology
SHEAF COHOMOLOGY ON THE ÉTALE SITE
Etale cohomology; L-adic cohomology; Étalé cohomology; ℓ-adic cohomology
In mathematics, the étale cohomology groups of an algebraic variety or scheme are algebraic analogues of the usual cohomology groups with finite coefficients of a topological space, introduced by Grothendieck in order to prove the Weil conjectures. Étale cohomology theory can be used to construct ℓ-adic cohomology, which is an example of a Weil cohomology theory in algebraic geometry.