The characteristic cycle and the singular support of an étale sheaf
Appears in collection : Arithmetic geometry, representation theory and applications / Géométrie arithmétique, théorie des représentations et applications
We define the characteristic cycle of an étale sheaf on a smooth variety of arbitrary dimension in positive characteristic using the singular support, constructed by Beilinson very recently. The characteristic cycle satisfies a Milnor formula for vanishing cycles and an index formula for the Euler-Poincaré characteristic.
