Michal Wrochna (Grenoble)
In Quantum Field Theory on curved spacetimes, the problem of constructing Wick powers of fields amounts to dealing with a priori ill-defined trace densities of certain Fourier Integral Operators. Instead of doing so directly, I will explain how this can be reduced to the case of elliptic (but in general non self-adjoint) pseudo-differential operators. This enables the use of renormalization methods that have quite different features from the broadly used Hadamard parametrix. (based on joint works with Christian Gérard)
