Szegő Kernel and Symplectic Aspects of Spectral Transform for Extended Spaces of Rational Matrices

We revisit the symplectic aspects of the spectral transform for matrix-valued rational functions with simple poles. We construct eigenvectors of such matrices in terms of the Szegő kernel on the spectral curve. Using variational formulas for the Szegő kernel, we construct a new system of action-angl...

Повний опис

Збережено в:
Бібліографічні деталі
Опубліковано в: :Symmetry, Integrability and Geometry: Methods and Applications
Дата:2023
Автори: Bertola, Marco, Korotkin, Dmitry, Sasani, Ramtin
Формат: Стаття
Мова:Англійська
Опубліковано: Інститут математики НАН України 2023
Онлайн доступ:https://nasplib.isofts.kiev.ua/handle/123456789/212027
Теги: Додати тег
Немає тегів, Будьте першим, хто поставить тег для цього запису!
Назва журналу:Digital Library of Periodicals of National Academy of Sciences of Ukraine
Цитувати:Szegő Kernel and Symplectic Aspects of Spectral Transform for Extended Spaces of Rational Matrices. Marco Bertola, Dmitry Korotkin and Ramtin Sasani. SIGMA 19 (2023), 104, 22 pages

Репозитарії

Digital Library of Periodicals of National Academy of Sciences of Ukraine
_version_ 1862577035540430848
author Bertola, Marco
Korotkin, Dmitry
Sasani, Ramtin
author_facet Bertola, Marco
Korotkin, Dmitry
Sasani, Ramtin
citation_txt Szegő Kernel and Symplectic Aspects of Spectral Transform for Extended Spaces of Rational Matrices. Marco Bertola, Dmitry Korotkin and Ramtin Sasani. SIGMA 19 (2023), 104, 22 pages
collection DSpace DC
container_title Symmetry, Integrability and Geometry: Methods and Applications
description We revisit the symplectic aspects of the spectral transform for matrix-valued rational functions with simple poles. We construct eigenvectors of such matrices in terms of the Szegő kernel on the spectral curve. Using variational formulas for the Szegő kernel, we construct a new system of action-angle variables for the canonical symplectic form on the space of such functions. Comparison with previously known action-angle variables shows that the vector of Riemann constants is the gradient of some function on the moduli space of spectral curves; this function is found in the case of matrix dimension 2, when the spectral curve is hyperelliptic.
first_indexed 2026-03-13T15:15:19Z
format Article
fulltext
id nasplib_isofts_kiev_ua-123456789-212027
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
issn 1815-0659
language English
last_indexed 2026-03-13T15:15:19Z
publishDate 2023
publisher Інститут математики НАН України
record_format dspace
spelling Bertola, Marco
Korotkin, Dmitry
Sasani, Ramtin
2026-01-23T10:07:52Z
2023
Szegő Kernel and Symplectic Aspects of Spectral Transform for Extended Spaces of Rational Matrices. Marco Bertola, Dmitry Korotkin and Ramtin Sasani. SIGMA 19 (2023), 104, 22 pages
1815-0659
2020 Mathematics Subject Classification: 53D30; 34M45
arXiv:2303.05602
https://nasplib.isofts.kiev.ua/handle/123456789/212027
https://doi.org/10.3842/SIGMA.2023.104
We revisit the symplectic aspects of the spectral transform for matrix-valued rational functions with simple poles. We construct eigenvectors of such matrices in terms of the Szegő kernel on the spectral curve. Using variational formulas for the Szegő kernel, we construct a new system of action-angle variables for the canonical symplectic form on the space of such functions. Comparison with previously known action-angle variables shows that the vector of Riemann constants is the gradient of some function on the moduli space of spectral curves; this function is found in the case of matrix dimension 2, when the spectral curve is hyperelliptic.
The work of M.B. was supported in part by the Natural Sciences and Engineering Research Council of Canada (NSERC) grant RGPIN-2016-06660. The work of D.K. was supported in part by the NSERC grant RGPIN-2020-06816.
en
Інститут математики НАН України
Symmetry, Integrability and Geometry: Methods and Applications
Szegő Kernel and Symplectic Aspects of Spectral Transform for Extended Spaces of Rational Matrices
Article
published earlier
spellingShingle Szegő Kernel and Symplectic Aspects of Spectral Transform for Extended Spaces of Rational Matrices
Bertola, Marco
Korotkin, Dmitry
Sasani, Ramtin
title Szegő Kernel and Symplectic Aspects of Spectral Transform for Extended Spaces of Rational Matrices
title_full Szegő Kernel and Symplectic Aspects of Spectral Transform for Extended Spaces of Rational Matrices
title_fullStr Szegő Kernel and Symplectic Aspects of Spectral Transform for Extended Spaces of Rational Matrices
title_full_unstemmed Szegő Kernel and Symplectic Aspects of Spectral Transform for Extended Spaces of Rational Matrices
title_short Szegő Kernel and Symplectic Aspects of Spectral Transform for Extended Spaces of Rational Matrices
title_sort szegő kernel and symplectic aspects of spectral transform for extended spaces of rational matrices
url https://nasplib.isofts.kiev.ua/handle/123456789/212027
work_keys_str_mv AT bertolamarco szegokernelandsymplecticaspectsofspectraltransformforextendedspacesofrationalmatrices
AT korotkindmitry szegokernelandsymplecticaspectsofspectraltransformforextendedspacesofrationalmatrices
AT sasaniramtin szegokernelandsymplecticaspectsofspectraltransformforextendedspacesofrationalmatrices