{ "meta": { "api_type": "NWO Projects API", "version": "1.0.2", "licence": { "name": "CC0 1.0 Universal", "url": "https://creativecommons.org/publicdomain/zero/1.0", "description": "To the extent possible under law, all copyright and related or neighbouring rights have been waived worldwide to the data made available through this API." }, "documentation": "https://doi.org/10.5281/zenodo.14918287", "release_date": "2025-08-20T00:00:00", "funder": "https://doi.org/10.13039/501100003246", "ror_id": "https://ror.org/04jsz6e67", "date": "2026-11-05T00:00:00", "count": 1, "per_page": 100, "pages": 1, "page": 1 }, "projects": [ { "project_id": "680-47-416", "title": "Thermal correlations in one dimensional quantum systems", "funding_scheme_id": 470, "funding_scheme": "NWO-Talentprogramma Veni 2010 N", "department": "Exacte en Natuurwetenschappen", "sub_department": "Natuurkunde", "start_date": "2011-01-01T00:00:00", "end_date": "2013-06-07T00:00:00", "reporting_year": 2010, "summary_nl": "The last 40 years have witnessed major improvements in our understanding of strongly-correlated physics, in many cases due to developments in the theory of exactly-solvable models. Fields such as one-dimensional integrable models witnessed a renaissance in the last ten years. With the help of optical and magnetic traps it became possible to experimentally realize integrable models and to measure novel properties of these strongly correlated systems. One of the main objectives from the theory side is to calculate space and time dependent correlation functions at finite (non-zero) temperature. \n\nThis proposal aims to contribute to the calculation of thermal correlations and to solve long-standing open problems in this field. The research will push forward the form factor approach to correlation functions, which was successfully applied previously to the zero temperature case. Two recently discovered ideas will be used to develop a general framework, which will be applied to a broad class of integrable models including relativistic field theories and non-relativistic many-body systems. \n\nRelativistic models (factorized scattering theories) will be approached with the help of a novel finite volume regularization scheme, which was partly developed by the applicant. The goal is to establish a low-temperature expansion based on the (zero-temperature) form factors. The results will be applicable to diverse models which admit a low-energy description in terms of field theory. The results will also shed light on one of the existing open problems, namely whether the ten-year old LeClair-Mussardo conjecture is valid for correlation functions.\n\nRecently discovered connections between the relativistic sinh-Gordon model and the non-relativistic theory of interacting bosons will pave the way for the calculation of previously unavailable results in the non-relativistic setting. Also, non-relativistic models will be approached by extending existing methods based on the Algebraic Bethe Ansatz and computer algorithms for the summation of the spectral series (ABACUS). \n", "summary_en": "The last 40 years have witnessed major improvements in our understanding of strongly-correlated physics, in many cases due to developments in the theory of exactly-solvable models. Fields such as one-dimensional integrable models witnessed a renaissance in the last ten years. With the help of optical and magnetic traps it became possible to experimentally realize integrable models and to measure novel properties of these strongly correlated systems. One of the main objectives from the theory side is to calculate space and time dependent correlation functions at finite (non-zero) temperature. \n\nThis proposal aims to contribute to the calculation of thermal correlations and to solve long-standing open problems in this field. The research will push forward the form factor approach to correlation functions, which was successfully applied previously to the zero temperature case. Two recently discovered ideas will be used to develop a general framework, which will be applied to a broad class of integrable models including relativistic field theories and non-relativistic many-body systems. \n\nRelativistic models (factorized scattering theories) will be approached with the help of a novel finite volume regularization scheme, which was partly developed by the applicant. The goal is to establish a low-temperature expansion based on the (zero-temperature) form factors. The results will be applicable to diverse models which admit a low-energy description in terms of field theory. The results will also shed light on one of the existing open problems, namely whether the ten-year old LeClair-Mussardo conjecture is valid for correlation functions.\n\nRecently discovered connections between the relativistic sinh-Gordon model and the non-relativistic theory of interacting bosons will pave the way for the calculation of previously unavailable results in the non-relativistic setting. Also, non-relativistic models will be approached by extending existing methods based on the Algebraic Bethe Ansatz and computer algorithms for the summation of the spectral series (ABACUS). \n", "project_members": [ { "role": "Project leader", "member_id": 220478, "last_name": "Pozsgay", "degree_pre_nominal": "dr.", "initials": "B.", "first_name": "Balázs", "organisation": "Universiteit van Amsterdam||Faculteit der Natuurwetenschappen, Wiskunde en Informatica (Faculty of Science)||Gravitation and Astroparticle Physics Amsterdam (GRAPPA)||Instituut voor Theoretische Fysica (ITFA)", "organisation_id": 75243, "ror": "https://ror.org/04dkp9463", "active": false }, { "role": "Researcher", "member_id": 220478, "last_name": "Pozsgay", "degree_pre_nominal": "dr.", "initials": "B.", "first_name": "Balázs", "organisation": "Universiteit van Amsterdam||Faculteit der Natuurwetenschappen, Wiskunde en Informatica (Faculty of Science)||Gravitation and Astroparticle Physics Amsterdam (GRAPPA)||Instituut voor Theoretische Fysica (ITFA)", "organisation_id": 75243, "ror": "https://ror.org/04dkp9463", "active": false }, { "role": "Main Applicant", "member_id": 220478, "last_name": "Pozsgay", "degree_pre_nominal": "dr.", "initials": "B.", "first_name": "Balázs", "organisation": "Budapest University of Technology and Economics||Department of Inorganic and Analytical Chemistry", "organisation_id": 59867, "ror": "-", "active": true } ], "products": [ { "title": "Form factor approach to diagonal finite volume matrix\nelements in Integrable QFT", "year": 2013, "edition": "1307", "start": 157, "end": 186, "type": "Wetenschappelijk artikel", "journal_title": "JHEP", "authors": [ { "last_name": "Pozsgay", "initials": "B", "role": "Auteur", "index_number": 1 } ] }, { "title": "Dynamical free energy and the Loschmidt-echo for a class of quantum quenches in the Heisenberg spin chain", "year": 2013, "type": "Wetenschappelijk artikel", "journal_title": "J. Stat. Mech. (accepted for publication)", "authors": [ { "last_name": "Pozsgay", "initials": "B", "role": "Auteur", "index_number": 1 } ] }, { "title": "Overlaps between eigenstates of the XXZ spin-1/2 chain and a class of simple product states", "year": 2013, "type": "Wetenschappelijk artikel", "journal_title": "arxiv eprints", "authors": [ { "last_name": "Pozsgay", "initials": "B", "role": "Auteur", "index_number": 1 } ] } ] } ] }