Fixed point formula of Lefschetz type in Arakelov geometry

R. Thomason has proved a concentration theorem for algebraic
equivariant K-theory on the schemes which are endowed with the action
of a diagonalisable group scheme. As usual, such a concentration
theorem induces a fixed point formula of Lefschetz type which can be
used to calculate the equivariant Euler-Poincare characteristics of
equivariant vector bundles. In this talk, I will try to explain how to
generalize Thomason's results to Arakelov geometry.