---
OA_place: publisher
OA_type: hybrid
PlanS_conform: '1'
_id: '22639'
abstract:
- lang: eng
  text: We present an abstract Dyson expansion for perturbations that are merely relatively
    form-bounded, and apply it to the polaron problem. For a large class of polaron-type
    models, including the Fröhlich and Nelson models, we prove that the vacuum expectation
    value of the heat semi-group is a completely monotone function of the square of
    the total momentum. Consequently, the ground-state energy is a concave function
    of the square of the momentum, a result recently proved for the Fröhlich model
    in [14] using a probabilistic approach via Wiener integrals.
acknowledgement: Open access funding provided by Institute of Science and Technology
  (IST Austria).
article_number: '87'
article_processing_charge: Yes (via OA deal)
article_type: original
arxiv: 1
author:
- first_name: Davide
  full_name: Desio, Davide
  id: ea10a57b-23f6-11ef-9085-80d8596d52ef
  last_name: Desio
  orcid: 0000-0001-9840-3809
- first_name: Robert
  full_name: Seiringer, Robert
  id: 4AFD0470-F248-11E8-B48F-1D18A9856A87
  last_name: Seiringer
  orcid: 0000-0002-6781-0521
citation:
  ama: Desio D, Seiringer R. Dyson expansion for form-bounded perturbations and applications
    to the polaron problem. <i>Letters in Mathematical Physics</i>. 2026;116(4). doi:<a
    href="https://doi.org/10.1007/s11005-026-02107-2">10.1007/s11005-026-02107-2</a>
  apa: Desio, D., &#38; Seiringer, R. (2026). Dyson expansion for form-bounded perturbations
    and applications to the polaron problem. <i>Letters in Mathematical Physics</i>.
    Springer Nature. <a href="https://doi.org/10.1007/s11005-026-02107-2">https://doi.org/10.1007/s11005-026-02107-2</a>
  chicago: Desio, Davide, and Robert Seiringer. “Dyson Expansion for Form-Bounded
    Perturbations and Applications to the Polaron Problem.” <i>Letters in Mathematical
    Physics</i>. Springer Nature, 2026. <a href="https://doi.org/10.1007/s11005-026-02107-2">https://doi.org/10.1007/s11005-026-02107-2</a>.
  ieee: D. Desio and R. Seiringer, “Dyson expansion for form-bounded perturbations
    and applications to the polaron problem,” <i>Letters in Mathematical Physics</i>,
    vol. 116, no. 4. Springer Nature, 2026.
  ista: Desio D, Seiringer R. 2026. Dyson expansion for form-bounded perturbations
    and applications to the polaron problem. Letters in Mathematical Physics. 116(4),
    87.
  mla: Desio, Davide, and Robert Seiringer. “Dyson Expansion for Form-Bounded Perturbations
    and Applications to the Polaron Problem.” <i>Letters in Mathematical Physics</i>,
    vol. 116, no. 4, 87, Springer Nature, 2026, doi:<a href="https://doi.org/10.1007/s11005-026-02107-2">10.1007/s11005-026-02107-2</a>.
  short: D. Desio, R. Seiringer, Letters in Mathematical Physics 116 (2026).
corr_author: '1'
das_tickbox: '0'
date_created: 2026-08-03T13:21:14Z
date_published: 2026-07-17T00:00:00Z
date_updated: 2026-08-04T05:57:21Z
day: '17'
ddc:
- '510'
department:
- _id: RoSe
- _id: GradSch
doi: 10.1007/s11005-026-02107-2
external_id:
  arxiv:
  - '2512.13443'
file:
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  creator: dernst
  date_created: 2026-08-04T05:55:58Z
  date_updated: 2026-08-04T05:55:58Z
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  file_name: 2026_LettersMathPhysics_Desio.pdf
  file_size: 371840
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file_date_updated: 2026-08-04T05:55:58Z
has_accepted_license: '1'
intvolume: '       116'
issue: '4'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '07'
oa: 1
oa_version: Published Version
publication: Letters in Mathematical Physics
publication_identifier:
  issn:
  - 1573-0530
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
researchdata_availability: no
scopus_import: '1'
status: public
supplementarymaterial: no
title: Dyson expansion for form-bounded perturbations and applications to the polaron
  problem
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 116
year: '2026'
...