Torsion sheaf explained

In mathematics, a torsion sheaf is a sheaf of abelian groups

l{F} on a site for which, for every object U, the space of sections \Gamma(U, l{F}) is a torsion abelian group. Similarly, for a prime number p, we say a sheaf l{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.

See also

• Twisted sheaf

References

• Web site: James S. . Milne . James Milne (mathematician) . 2012 . Lectures on Étale Cohomology.
• J. S. Milne, Étale Cohomology
• Book: Fu, Lei. 10.1142/9569. Etale Cohomology Theory . Nankai Tracts in Mathematics . 2015 . 14 . 978-981-4675-08-6 .