Torsion sheaf

In mathematics, a torsion sheaf is a sheaf of abelian groups $\mathcal{F}$ on a site for which, for every object U, the space of sections $\Gamma(U, \mathcal{F})$ is a torsion abelian group. Similarly, for a prime number p, we say a sheaf $\mathcal{F}$ is p-torsion if every section over any object is killed by a power of p.

A torsion sheaf on an étale site is the union of its constructible subsheaves.{{harvnb|Milne|2012|loc=Remark 17.6}}

==See also ==

Twisted sheaf

Notes

References

{{cite web |first=James S. |last=Milne |author-link=James Milne (mathematician) |year=2012 |url=https://www.jmilne.org/math/CourseNotes/LEC.pdf |title=Lectures on Étale Cohomology}}
J. S. Milne, Étale Cohomology
{{cite book |first=Lei|last=Fu|doi=10.1142/9569|title=Etale Cohomology Theory |series=Nankai Tracts in Mathematics |year=2015 |volume=14 |isbn=978-981-4675-08-6 }}

Category:Sheaf theory