Torsion sheaf

In mathematics, a torsion sheaf is a sheaf F on a site for which, for every quasi-compact U, the space of sections Γ ( U , F ) is a torsion group. Similarly, for a prime number l, we say a sheaf F is l-torsion if every section over any quasi-compact is killed by a power of l.

A torsion sheaf on an étale site is the union of its constructible subsheaves.