title: Independence of ℓ and traces on cohomology.
abstract: Let k be an algebraically closed field, and let [Formula: see text] be an endomorphism of a separated scheme of finite type over k We show that for any [Formula: see text] invertible in k, the alternating sum of traces [Formula: see text] of pullback on étale cohomology is a rational number independent of [Formula: see text] This is deduced from a more general result for motivic sheaves.
authors.affiliation: Department of Mathematics, University of California, Berkeley, CA 94720 molsson@math.berkeley.edu.
authors.forename: Martin
authors.initials: M
authors.lastname: Olsson
keywords: independence of ℓ; motives; étale cohomology