dc.contributor.author LIll, S. dc.date.accessioned 2022-06-23T14:01:34Z dc.date.available 2022-06-23T14:01:34Z dc.date.issued 2022-06-04 dc.identifier.uri http://hdl.handle.net/20.500.11824/1480 dc.description.abstract In quantum field theory (QFT) models, it often seems natural to use, instead of wave functions from Fock space, wave functions that are not square-integrable and have prefactors involving divergent integrals (known as infinite wave function renormalizations). Here, we rigorously construct vector spaces containing divergent integrals, as well as two extended state vector spaces, which contain a dense subspace of Fock space, but also incorporate non-square-integrable wave functions with infinite wave function renormalizations. en_US As a demonstration, we apply this construction to a non-perturbative renormalization of a class of simple non-relativistic QFT models, which are polaron models with resting fermions. The Hamiltonian without cutoffs, an infinite self-energy and a dressing transformation are defined as linear operators on certain subspaces of the two Fock space extensions. This way, we can obtain a renormalized Hamiltonian which can be realized as a densely defined self-adjoint operator on Fock space. dc.description.sponsorship Wilhelm Schuler-Stiftung Tübingen, en_US DAAD (Deutscher Akademischer Austauschdienst) dc.format application/pdf en_US dc.language.iso eng en_US dc.rights Reconocimiento-NoComercial-CompartirIgual 3.0 España en_US dc.rights.uri http://creativecommons.org/licenses/by-nc-sa/3.0/es/ en_US dc.subject Non-perturbative QFT; renormalization; divergent integrals; Van Hove model; Fock space; Hamiltonian Formalism; dressing transformation; interior-boundary conditions (IBC) en_US dc.title Extended State Space for Describing Renormalized Fock Spaces in QFT en_US dc.type info:eu-repo/semantics/article en_US dc.identifier.arxiv 2012.12608 dc.relation.publisherversion https://arxiv.org/abs/2012.12608 en_US dc.relation.projectID ES/1PE/SEV-2017-0718 en_US dc.relation.projectID EUS/BERC/BERC.2018-2021 en_US dc.rights.accessRights info:eu-repo/semantics/openAccess en_US dc.type.hasVersion info:eu-repo/semantics/submittedVersion en_US
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