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16. May 2023, 14:00 until 15:00

Infrared Finite Scattering Theory in QFT and Quantum Gravity

Seminar

Seminar talk

A long-standing problem in QFT and quantum gravity is the construction of an "IR-finite" S-matrix. In the gravitational case,
the existence of these "infrared divergences" is intimately tied to the "memory effect" (i.e. the permanent displacement of test masses due to the passage of a gravitational wave).
In this talk, I shall explain the origin of these connections and illustrate that the construction of an IR-finite S-matrix requires the inclusion of states with memory (which do not lie in the standard Fock space).
In massive QED an elegant solution to this problem was provided by Faddeev and Kulish who constructed an incoming/outgoing Hilbert space of charged particles "dressed" with memory.
We illustrate the "preferred status" of such states and their relationship to the superselection/decoherence structure of QED. However, we show that this construction fails [...]

Calendar entry

Event details

Event location

1090 Erwin-Schrödinger-Hörsaal
Boltzmanngasse 5, 5. Stock
Public
Yes
Entrance fee
No
Registration required
No