Causal perturbative QFT with Hida operators and space-time geometry
Seminars
Bogoliubov Laboratory of Theoretical Physics
Joint seminar “Quantum Field Theory” and “Modern Mathematical Physics”
Date and Time: Wednesday, 17 September 2025, at 11:00 AM
Venue: Blokhintsev lecture hall, Bogoliubov Laboratory of Theoretical Physics, online on Zoom
Seminar topic: “Causal perturbative QFT with Hida operators and space-time geometry”
Speaker: Jaroslaw Wawrzycki
The seminar will be devoted to the Bogoliubov perturbative QFT on the Minkowski space-time and on the Einstein Universe (EU). Essential novelty of the approach comes from using the so-called Hida white noise operators as the free field creation-annihilation operators, converting higher order contributions to the scattering operator and to interacting field operators, into generalised integral kernel operators. This approach allows the authors to solve some of IR problems. Existence of the higher order contributions puts nontrivial restrictions on the degree of the massless fields in the interaction terms. The authors provide a theoretical proof that electrically charged particle should have a nonzero mass – one of the problems of theoretical QFT. They mention some other problems solved using this approach, including a rigorous construction of the Feynman integral on the compactified EU, which is applicable in non-perturbative numerical computations on EU. Some other results within nonperturbative QFT will be mentioned concerning rigorous analysis of the full Hamiltonian operators in the Schroedinger picture of realistic systems (e.g. the electroweak) on EU, for the comparison with perturbative approach.