Accessory Parameters for Four-Punctured Spheres

We study the accessory parameter problem for four-punctured spheres from the point of view of modular forms. The value of the accessory parameter giving the uniformization is characterized as the unique zero of a system of equations. This gives an effective method to compute the uniformizing differe...

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Veröffentlicht in:Symmetry, Integrability and Geometry: Methods and Applications
Datum:2022
1. Verfasser: Bogo, Gabriele
Format: Artikel
Sprache:Englisch
Veröffentlicht: Інститут математики НАН України 2022
Online Zugang:https://nasplib.isofts.kiev.ua/handle/123456789/211521
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Назва журналу:Digital Library of Periodicals of National Academy of Sciences of Ukraine
Zitieren:Accessory Parameters for Four-Punctured Spheres. Gabriele Bogo. SIGMA 18 (2022), 024, 20 pages

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
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author Bogo, Gabriele
author_facet Bogo, Gabriele
citation_txt Accessory Parameters for Four-Punctured Spheres. Gabriele Bogo. SIGMA 18 (2022), 024, 20 pages
collection DSpace DC
container_title Symmetry, Integrability and Geometry: Methods and Applications
description We study the accessory parameter problem for four-punctured spheres from the point of view of modular forms. The value of the accessory parameter giving the uniformization is characterized as the unique zero of a system of equations. This gives an effective method to compute the uniformizing differential equation. As an application, we compute numerically and study the local expansion of the real-analytic function associated with a four-punctured sphere, the value of its uniformizing parameter, and make some observations on its coefficients.
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last_indexed 2026-04-17T15:51:08Z
publishDate 2022
publisher Інститут математики НАН України
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spelling Bogo, Gabriele
2026-01-05T12:23:57Z
2022
Accessory Parameters for Four-Punctured Spheres. Gabriele Bogo. SIGMA 18 (2022), 024, 20 pages
1815-0659
2020 Mathematics Subject Classification: 30F35; 34M03; 32G15
arXiv:2004.02971
https://nasplib.isofts.kiev.ua/handle/123456789/211521
https://doi.org/10.3842/SIGMA.2022.024
We study the accessory parameter problem for four-punctured spheres from the point of view of modular forms. The value of the accessory parameter giving the uniformization is characterized as the unique zero of a system of equations. This gives an effective method to compute the uniformizing differential equation. As an application, we compute numerically and study the local expansion of the real-analytic function associated with a four-punctured sphere, the value of its uniformizing parameter, and make some observations on its coefficients.
The paper was written while I was a graduate student at SISSA (International School for Advanced Studies) in Trieste and a visiting student of the IMPRS graduate school at the Max Planck Institute for Mathematics in Bonn. I want to thank both institutions for the excellent working conditions. I want to thank my advisers, Don Zagier and Fernando Rodriguez Villegas, for their suggestions and support, and Giordano Cotti for very useful conversations. Finally, I thank the anonymous referees, whose suggestions and remarks gave a relevant contribution to improving the paper.
en
Інститут математики НАН України
Symmetry, Integrability and Geometry: Methods and Applications
Accessory Parameters for Four-Punctured Spheres
Article
published earlier
spellingShingle Accessory Parameters for Four-Punctured Spheres
Bogo, Gabriele
title Accessory Parameters for Four-Punctured Spheres
title_full Accessory Parameters for Four-Punctured Spheres
title_fullStr Accessory Parameters for Four-Punctured Spheres
title_full_unstemmed Accessory Parameters for Four-Punctured Spheres
title_short Accessory Parameters for Four-Punctured Spheres
title_sort accessory parameters for four-punctured spheres
url https://nasplib.isofts.kiev.ua/handle/123456789/211521
work_keys_str_mv AT bogogabriele accessoryparametersforfourpuncturedspheres