Higher Intersection Theory on Algebraic Stacks II, by Roy Joshua
This is the second part of our work on the intersection theory of algebraic
stacks. Here we establish the existence of Chern classes and Chern character
for all Artin stacks of finite type over a field with values in our Chow
groups. We also extend these to higher Chern classes and a higher Chern
character for {\it perfect complexes} on an algebraic stack, taking values in
cohomology theories of algebraic stacks that are defined with respect to
complexes of sheaves on the big smooth site. We also provide an integral
intersection pairing for all smooth Artin stacks which we show reduces to the
known intersection pairing on the Chow groups of smooth Deligne-Mumford
stacks modulo torsion. This involves showing the existence of Adams
operations on the rational \'etale K-theory of all smooth Deligne-Mumford
stacks. As a by-product of our techniques we also provide an extension of
higher intersection theory to all schemes of finite type over a field.
Roy Joshua <joshua@math.ohio-state.edu>