Research objectives and content
Mathematical tools of infinite dimensional analysis developed by the applicant and collaborators in Germany and Japan are to be applied to physical problems presently studied in Lisbon. These include: Feynman Integrals, originally a heuristic tool of quantum physics, have been identified as elements in the Hida space of generalized Brownian functionals. Thus a rapidly increasing number of quantum mechanical models allows for a reliable treatment using Feynman integrals. The emerging picture of oscillatory integrals reveals surprising differences from the "Euclidean" approach: there are many physically interesting cases where contrary to folk lore, the former are better behaved than the latter. This is to be explored systematically, with a view towards quantum field theories without the Euclidean detour. An example is the recent study of the Chern-Simons gauge field theory directly for Minkowski space time, to be continued in Lisbon with Prof. Vilela Mendes. Non-oscillatory Integrals. We have given a rigorous meaning to the densities (w.r. to suitable Gaussian measures) of physical field theoretical vacua, an object explored within physical approximation schemes by the Lisbon group; a blending of methods appears very promising. Finally, more should be learned about the transformation of variables in functional integrals for specific physical problems.
Training content (objective, benefit and expected impact)
Through lectures. seminars, discussions, and orientation of thesis work Presentation of scientific expertise complementary to that already existing in Lisbon with the goals: - For established researchers a strengthening of their technical expertise, - for graduate students scientific counseling in a new and promising field of mathematical physics, leading to - joint scientific work and publications of new results in mathematical physics