[{"type":"journal_article","doi":"10.1007/s11005-026-02107-2","publication_identifier":{"issn":["1573-0530"]},"citation":{"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>.","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.","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>.","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>","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.","short":"D. Desio, R. Seiringer, Letters in Mathematical Physics 116 (2026)."},"month":"07","file":[{"success":1,"file_name":"2026_LettersMathPhysics_Desio.pdf","date_updated":"2026-08-04T05:55:58Z","relation":"main_file","access_level":"open_access","creator":"dernst","checksum":"1b90ff7da16b9604d6fe2c6281493456","content_type":"application/pdf","file_id":"22641","date_created":"2026-08-04T05:55:58Z","file_size":371840}],"researchdata_availability":"no","date_published":"2026-07-17T00:00:00Z","day":"17","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."}],"arxiv":1,"oa_version":"Published Version","article_type":"original","tmp":{"image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"ddc":["510"],"date_updated":"2026-08-04T05:57:21Z","acknowledgement":"Open access funding provided by Institute of Science and Technology (IST Austria).","status":"public","quality_controlled":"1","OA_place":"publisher","title":"Dyson expansion for form-bounded perturbations and applications to the polaron problem","external_id":{"arxiv":["2512.13443"]},"article_number":"87","department":[{"_id":"RoSe"},{"_id":"GradSch"}],"author":[{"full_name":"Desio, Davide","last_name":"Desio","orcid":"0000-0001-9840-3809","id":"ea10a57b-23f6-11ef-9085-80d8596d52ef","first_name":"Davide"},{"full_name":"Seiringer, Robert","last_name":"Seiringer","id":"4AFD0470-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-6781-0521","first_name":"Robert"}],"date_created":"2026-08-03T13:21:14Z","scopus_import":"1","article_processing_charge":"Yes (via OA deal)","_id":"22639","language":[{"iso":"eng"}],"das_tickbox":"0","publisher":"Springer Nature","OA_type":"hybrid","has_accepted_license":"1","oa":1,"PlanS_conform":"1","publication_status":"published","year":"2026","file_date_updated":"2026-08-04T05:55:58Z","volume":116,"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","supplementarymaterial":"no","publication":"Letters in Mathematical Physics","issue":"4","intvolume":"       116","corr_author":"1"}]