Grothendieck–Lefschetz trace formula
E904007
The Grothendieck–Lefschetz trace formula is a fundamental result in algebraic geometry that expresses the number of rational points of a variety over a finite field in terms of traces of Frobenius acting on its étale cohomology groups.
Statements (45)
| Predicate | Object |
|---|---|
| instanceOf |
mathematical theorem
ⓘ
result in algebraic geometry ⓘ |
| appliesTo | variety over a finite field ⓘ |
| assumes |
continuous action of Frobenius on cohomology
ⓘ
variety of finite type over a finite field ⓘ |
| category | cohomological fixed-point theorem ⓘ |
| cohomologicalDegree | alternating sum over all i ≥ 0 ⓘ |
| context |
derived category of ℓ-adic sheaves
ⓘ
schemes over finite fields ⓘ |
| domain | finite fields ⓘ |
| expresses | number of F_q-rational points as an alternating sum of traces of Frobenius ⓘ |
| field |
algebraic geometry
ⓘ
arithmetic geometry ⓘ |
| framework | Grothendieck’s theory of étale cohomology ⓘ |
| generalizationOf |
Lefschetz fixed-point theorem
NERFINISHED
ⓘ
Lefschetz trace formula NERFINISHED ⓘ |
| hasVariant |
relative trace formula for morphisms
ⓘ
version for non-proper varieties using compact support ⓘ |
| holdsFor | smooth projective varieties over finite fields ⓘ |
| inspired | later trace formulas in arithmetic geometry ⓘ |
| involves |
Weil cohomology theory
NERFINISHED
ⓘ
compactly supported étale cohomology ⓘ ℓ-adic cohomology ⓘ |
| isPartOf | Grothendieck’s program for the Weil conjectures ⓘ |
| motivationFor | development of ℓ-adic cohomology ⓘ |
| namedAfter |
Alexander Grothendieck
NERFINISHED
ⓘ
Solomon Lefschetz NERFINISHED ⓘ |
| output | equality between point count and cohomological trace sum ⓘ |
| relatedTo |
Hasse–Weil zeta function
NERFINISHED
ⓘ
Weil conjectures on zeta functions of varieties NERFINISHED ⓘ |
| relates |
number of rational points
ⓘ
traces of Frobenius on étale cohomology ⓘ |
| requires |
finiteness of étale cohomology groups
ⓘ
trace class action of Frobenius on cohomology ⓘ |
| statedInTermsOf |
action of geometric Frobenius on cohomology
ⓘ
fixed points of Frobenius on the variety ⓘ |
| toolFor |
Weil conjectures
NERFINISHED
ⓘ
arithmetic applications of cohomology ⓘ counting points on varieties over finite fields ⓘ |
| type | cohomological trace formula ⓘ |
| usedIn |
proofs of rationality of zeta functions of varieties over finite fields
ⓘ
study of eigenvalues of Frobenius ⓘ |
| usesConcept |
Frobenius endomorphism
NERFINISHED
ⓘ
trace of an endomorphism ⓘ étale cohomology ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.