A new two-parameter family of isomonodromic deformations over the five punctured sphere
[Une nouvelle famille à deux paramètres de déformations isomonodromiques sur la sphère à cinq trous]
Bulletin de la Société Mathématique de France, Tome 144 (2016) no. 2, pp. 339-368

The object of this paper is to describe an explicit two-parameter family of logarithmic flat connections over the complex projective plane. These connections have dihedral monodromy and their polar locus is a prescribed quintic composed of a conic and three tangent lines. By restricting them to generic lines we get an algebraic family of isomonodromic deformations of the five-punctured sphere. This yields new algebraic solutions of a Garnier system. Finally, we use the associated Riccati one-forms to construct and prove the integrability (in the transversally projective sense) of a subfamily of Lotka-Volterra foliations.

Le but de cet article est de décrire une famille explicite à deux paramètres de connexions logarithmiques plates au dessus du plan projectif complexe. Ces connexions sont à monodromie diédrale et leur lieu polaire est une quintique prescrite, composée d'une conique et de trois droites tangentes. Par restriction aux droites génériques, on obtient alors une famille algébrique de déformations isomonodromiques de la sphère à cinq trous. Ceci livre de nouvelles solutions algébriques d'un système de Garnier. Enfin, nous utilisons les formes de Riccati associées à ces connexions pour construire et montrer l'intégrabilité (au sens transversalement projectif) d'une sous-famille de feuilletages de Lotka-Volterra.

Publié le :
DOI : 10.24033/bsmf.2716
Classification : 14E22, 20G05, 20G20, 32D15, 32G08, 32G34, 34M50, 34M56, 51N15, 55R10
Keywords: Isomonodromic deformations, Garnier systems, logarithmic flat connections, transversally projective foliations, Lotka-Volterra systems, Riccati forms, dihedral monodromy groups.
Mots-clés : Déformations isomonodromiques, systèmes de Garnier, connexions logarithmiques plates, feuilletages transversalement projectifs, systèmes de Lotka-Volterra, formes de Riccati, groupes de monodromie diédraux.
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     title = {A new two-parameter family of isomonodromic deformations over the five punctured sphere},
     journal = {Bulletin de la Soci\'et\'e Math\'ematique de France},
     pages = {339--368},
     year = {2016},
     publisher = {Soci\'et\'e math\'ematique de France},
     volume = {144},
     number = {2},
     doi = {10.24033/bsmf.2716},
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Girand, Arnaud. A new two-parameter family of isomonodromic deformations over the five punctured sphere. Bulletin de la Société Mathématique de France, Tome 144 (2016) no. 2, pp. 339-368. doi: 10.24033/bsmf.2716

Beauville, A. Complex Algebraic Surfaces, Cambridge Univ. Press, 1983 | MR | Zbl

Casale, G. Feuilletages singuliers de codimension un, groupoïde de Galois et intégrales premières, Ann. Inst. Fourier (Grenoble), Volume 56 (2006), pp. 735-779 | MR | Zbl | Numdam | DOI

Cerveau, D.; Lins Neto, A. Holomorphic foliations in 𝐂P(2) having an invariant algebraic curve, Ann. Inst. Fourier (Grenoble), Volume 41 (1991), pp. 883-903 | MR | Zbl | Numdam | DOI

Corlette, K.; Simpson, C. On the classification of rank-two representations of quasiprojective fundamental groups, Compos. Math., Volume 144 (2008), pp. 1271-1331 | MR | Zbl | DOI

Degtyarev, A. I. Quintics in 𝐂P2 with nonabelian fundamental group, Algebra i Analiz, Volume 11 (1999), pp. 130-151 | MR | Zbl

Diarra, K. Construction et classification de certaines solutions algébriques des systèmes de Garnier, Bull. Braz. Math. Soc., Volume 44 (2013), pp. 129-154 | MR | Zbl | DOI

Diarra, K. Solutions algébriques partielles des équations isomonodromiques sur les courbes de genre 2 (preprint arXiv:1312.6233 ) | MR | Numdam

Girand, A. Équations d'isomonodromie, solutions algébriques et dynamique, Ph. D. Thesis , Université de Rennes 1 (in preparation)

Hitchin, N. J., Geometry and analysis (Bombay, 1992), Tata Inst. Fund. Res., Bombay, 1995, pp. 151-185 | MR | Zbl

Jimbo, M.; Miwa, T. Monodromy preserving deformation of linear ordinary differential equations with rational coefficients. II, Phys. D, Volume 2 (1981), pp. 407-448 | Zbl | MR | DOI

Kollàr, J. Rational curves on algebraic varieties, Ergebn. der Math. und ihrer Grenzg., 32, Springer, 1999, 321 pages | MR | Zbl

Lins Neto, A. Some examples for the Poincaré and Painlevé problems, Ann. Sci. École Norm. Sup., Volume 35 (2002), pp. 231-266 | MR | Zbl | Numdam | DOI

Loray, F.; Touzet, F.; Vitorio Pereira, J. Representations of quasiprojective groups, flat connections and transversely projective foliations (preprint arXiv:1402.1382 ) | MR

Mazzocco, M. The geometry of the classical solutions of the Garnier systems, Int. Math. Res. Not., Volume 2002 (2002), pp. 613-646 | MR | Zbl | DOI

Milnor, J. Morse theory, Based on lecture notes by M. Spivak and R. Wells. Annals of Math. Studies, No. 51, Princeton Univ. Press, Princeton, N.J., 1963, 153 pages | MR | Zbl | DOI

Moulin Ollagnier, J. Liouvillian integration of the Lotka-Volterra system, Qual. Theory Dyn. Syst., Volume 2 (2001), pp. 307-358 | MR | Zbl | DOI

Moulin Ollagnier, J. Corrections and complements to: “Liouvillian integration of the Lotka-Volterra system” [Qual. Theory Dyn. Syst. 2 (2001), no. 2, 307–358], Qual. Theory Dyn. Syst., Volume 5 (2004), pp. 275-284 | MR | Zbl | DOI

Scárdua, B. A. Transversely affine and transversely projective holomorphic foliations, Ann. Sci. École Norm. Sup., Volume 30 (1997), pp. 169-204 | MR | Zbl | Numdam | DOI

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