Arithmetic
Weight Complexes, Arithmetic Geometry Conference at the

Motivic cohomology and Arakelov
Theory, talk
at given at workshop in

Lectures on Arakelov Theory at the
workshop on Algebraic
Cycles, Morelia Mexico

Line Bundles on Stacks an informal lecture at the
workshop “Learning
Stacks and Computational
Methods through Problem-Solving”

Can one do arithmetic intersection theory on stacks? Workshop on "Intersection Theory on Stacks " at MSRI in March of 2002.

Differential algebraic geometry - A scheme theoretic approach Workshop on "Model Theory, Algebra and Arithmetic" at MSRI in June of 1998.