Curing velocity superselection in non-relativistic QED by restriction to a lightcone
arXiv:1902.09478 · doi:10.1007/s00023-020-00932-2
Abstract
It is physically expected that plane-wave configurations of the electron in QED induce disjoint representations of the algebra of the electromagnetic fields. This phenomenon of velocity superselection, which is one aspect of the infrared problem, is mathematically well established in non-relativistic (Pauli-Fierz type) models of QED. We show that velocity superselection can be resolved in such models by restricting the electron states to the subalgebra of the fields localized in the future lightcone. This actually follows from a more general statement about equivalence of GNS representations for coherent states of the algebra of the future lightcone in free electromagnetism. Our analysis turns out to be meaningful in the non-relativistic setting and provides evidence in favour of the Buchholz-Roberts approach to infrared problems.
19 pages, 1 figure. New results added
References in corpus (4)
- Absence of Ground States for a Class of Translation Invariant Models of Non-relativistic QED
- Asymptotic charges, large gauge transformations and inequivalence of different gauges in external current QED
- Relative normalizers of automorphism groups, infravacua and the problem of velocity superselection in QED
- A soft-photon theorem for the Maxwell-Lorentz system