Classifying Toric and Semitoric Fans by Lifting Equations from SL₂(Z)

We present an algebraic method to study four-dimensional toric varieties by lifting matrix equations from the special linear group SL₂(Z) to its preimage in the universal cover of SL₂(R) . With this method, we recover the classification of two-dimensional toric fans and obtain a description of their...

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Veröffentlicht in:Symmetry, Integrability and Geometry: Methods and Applications
Datum:2018
Hauptverfasser: Kane, D.M., Palmer, J., Pelayo, Á.
Format: Artikel
Sprache:Englisch
Veröffentlicht: Інститут математики НАН України 2018
Online Zugang:https://nasplib.isofts.kiev.ua/handle/123456789/209448
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Zitieren:Classifying Toric and Semitoric Fans by Lifting Equations from SL₂(Z) / D.M. Kane, J. Palmer, Á. Pelayo // Symmetry, Integrability and Geometry: Methods and Applications. — 2018. — Т. 14. — Бібліогр.: 48 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
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author Kane, D.M.
Palmer, J.
Pelayo, Á.
author_facet Kane, D.M.
Palmer, J.
Pelayo, Á.
citation_txt Classifying Toric and Semitoric Fans by Lifting Equations from SL₂(Z) / D.M. Kane, J. Palmer, Á. Pelayo // Symmetry, Integrability and Geometry: Methods and Applications. — 2018. — Т. 14. — Бібліогр.: 48 назв. — англ.
collection DSpace DC
container_title Symmetry, Integrability and Geometry: Methods and Applications
description We present an algebraic method to study four-dimensional toric varieties by lifting matrix equations from the special linear group SL₂(Z) to its preimage in the universal cover of SL₂(R) . With this method, we recover the classification of two-dimensional toric fans and obtain a description of their semitoric analogue. As an application to symplectic geometry of Hamiltonian systems, we give a concise proof of the connectivity of the moduli space of toric integrable systems in dimension four, recovering a known result, and extend it to the case of semitoric integrable systems with a fixed number of focus-focus points and which are in the same twisting index class. In particular, we show that any semitoric system with precisely one focus-focus singular point can be continuously deformed into a system in the same isomorphism class as the Jaynes-Cummings model from optics.
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language English
last_indexed 2025-12-07T15:57:37Z
publishDate 2018
publisher Інститут математики НАН України
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spelling Kane, D.M.
Palmer, J.
Pelayo, Á.
2025-11-21T19:01:28Z
2018
Classifying Toric and Semitoric Fans by Lifting Equations from SL₂(Z) / D.M. Kane, J. Palmer, Á. Pelayo // Symmetry, Integrability and Geometry: Methods and Applications. — 2018. — Т. 14. — Бібліогр.: 48 назв. — англ.
1815-0659
2010 Mathematics Subject Classification: 52B20; 15B36; 53D05
arXiv: 1502.07698
https://nasplib.isofts.kiev.ua/handle/123456789/209448
https://doi.org/10.3842/SIGMA.2018.016
We present an algebraic method to study four-dimensional toric varieties by lifting matrix equations from the special linear group SL₂(Z) to its preimage in the universal cover of SL₂(R) . With this method, we recover the classification of two-dimensional toric fans and obtain a description of their semitoric analogue. As an application to symplectic geometry of Hamiltonian systems, we give a concise proof of the connectivity of the moduli space of toric integrable systems in dimension four, recovering a known result, and extend it to the case of semitoric integrable systems with a fixed number of focus-focus points and which are in the same twisting index class. In particular, we show that any semitoric system with precisely one focus-focus singular point can be continuously deformed into a system in the same isomorphism class as the Jaynes-Cummings model from optics.
We thank the anonymous referees for reading the paper carefully and providing very helpful suggestions, which have improved the paper. JP and ÁP were partially supported by NSF grants DMS-1055897 and DMS-1518420.
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Інститут математики НАН України
Symmetry, Integrability and Geometry: Methods and Applications
Classifying Toric and Semitoric Fans by Lifting Equations from SL₂(Z)
Article
published earlier
spellingShingle Classifying Toric and Semitoric Fans by Lifting Equations from SL₂(Z)
Kane, D.M.
Palmer, J.
Pelayo, Á.
title Classifying Toric and Semitoric Fans by Lifting Equations from SL₂(Z)
title_full Classifying Toric and Semitoric Fans by Lifting Equations from SL₂(Z)
title_fullStr Classifying Toric and Semitoric Fans by Lifting Equations from SL₂(Z)
title_full_unstemmed Classifying Toric and Semitoric Fans by Lifting Equations from SL₂(Z)
title_short Classifying Toric and Semitoric Fans by Lifting Equations from SL₂(Z)
title_sort classifying toric and semitoric fans by lifting equations from sl₂(z)
url https://nasplib.isofts.kiev.ua/handle/123456789/209448
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