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Galois-theoretic characterization of isomorphism classes of monodromically full hyperbolic curves of genus zero

Published online by Cambridge University Press:  11 January 2016

Yuichiro Hoshi*
Affiliation:
Research Institute for Mathematical Sciences, Kyoto University, Kyoto 606-8502, Japanyuichiro@kurims.kyoto-u.ac.jp
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Abstract

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Let l be a prime number. In this paper, we prove that the isomorphism class of an l-monodromically full hyperbolic curve of genus zero over a finitely generated extension of the field of rational numbers is completely determined by the kernel of the natural pro-l outer Galois representation associated to the hyperbolic curve. This result can be regarded as a genus zero analogue of a result due to Mochizuki which asserts that the isomorphism class of an elliptic curve which does not admit complex multiplication over a number field is completely determined by the kernels of the natural Galois representations on the various finite quotients of its Tate module.

Keywords

Type
Research Article
Copyright
Copyright © Editorial Board of Nagoya Mathematical Journal 2011

References

[1] Anderson, M. P., Exactness properties of profinite completion functors, Topology 13 (1974), 229239.CrossRefGoogle Scholar
[2] Anderson, G. and Ihara, Y., Pro-l branched coverings of P1 and higher circular l-units, Ann. of Math. (2) 128 (1988), 271293.CrossRefGoogle Scholar
[3] Asada, M., The faithfulness of the monodromy representations associated with certain families of algebraic curves, J. Pure Appl. Algebra 159 (2001), 123147.CrossRefGoogle Scholar
[4] Chai, C. L. and Oort, F., A note on the existence of absolutely simple Jacobians, J. Pure Appl. Algebra 155 (2001), 115120.CrossRefGoogle Scholar
[5] Deligne, P. and Mumford, D., The irreducibility of the space of curves of given genus, Publ. Math. Inst. Hautes Études Sci. 36 (1969), 75109.CrossRefGoogle Scholar
[6] Grothendieck, A. and Dieudonné, J., Éléments de géométrie algébrique, III: Études cohomologique des faisceaux cohérents, I, Publ. Math. Inst. Hautes Études Sci. 11 (1961).Google Scholar
[7] Grothendieck, A. and Dieudonné, J., Groupes de monodromie en géométrie algébrique, I, Séminaire de Géométrie Algébrique du Bois-Marie (SGA 7 I), Lecture Notes in Math. 288, Springer, Berlin, 1972.Google Scholar
[8] Hoshi, Y. and Mochizuki, S., On the combinatorial anabelian geometry of nodally nondegenerate outer representations, preprint, to appear in Hiroshima Math. J.Google Scholar
[9] Ihara, Y. and Nakamura, H., On deformation of maximally degenerate stable marked curves and Oda’s problem, J. Reine Angew. Math. 487 (1997), 125151.Google Scholar
[10] Knudsen, F., The projectivity of the moduli space of stable curves, II: The stacks Mg,n , Math. Scand. 52 (1983), 161199.CrossRefGoogle Scholar
[11] Matsumoto, M. and Tamagawa, A., Mapping-class-group action versus Galois action on profinite fundamental groups, Amer. J. Math. 122 (2000), 10171026.CrossRefGoogle Scholar
[12] Mochizuki, S., Correspondences on hyperbolic curves, J. Pure Appl. Algebra 131 (1998), 227244.CrossRefGoogle Scholar
[13] Mochizuki, S., The local pro-p anabelian geometry of curves, Invent. Math. 138 (1999), 319423.CrossRefGoogle Scholar
[14] Mochizuki, S., “Topics surrounding the anabelian geometry of hyperbolic curves” in Galois Groups and Fundamental Groups, Math. Sci. Res. Inst. Publ. 41, Cambridge University Press, Cambridge, 2003, 119165.Google Scholar
[15] Mochizuki, S., “The absolute anabelian geometry of hyperbolic curves” in Galois Theory and Modular Forms, Dev. Math. 11, Kluwer, Boston, 2004, 77122.Google Scholar
[16] Mochizuki, S. and Tamagawa, A., The algebraic and anabelian geometry of configuration spaces, Hokkaido Math. J. 37 (2008), 75131.CrossRefGoogle Scholar
[17] Nakamura, H., Galois rigidity of pure sphere braid groups and profinite calculus, J. Math. Sci. Univ. Tokyo 1 (1994), 71136.Google Scholar
[18] Nakamura, H., Takao, N., and Ueno, R., Some stability properties of Teichmüller modular function fields with pro-l weight structures, Math. Ann. 302 (1995), 197213.CrossRefGoogle Scholar
[19] Neukirch, J., Algebraic Number Theory, Grundlehren Math. Wiss. 322, Springer, Berlin, 1999.Google Scholar
[20] Oda, T., “Etale homotopy type of the moduli spaces of algebraic curves” in Geometric Galois Actions, Vol. 1, London Math. Soc. Lecture Note Ser. 242, Cambridge University Press, Cambridge, 1997, 8595.Google Scholar
[21] Poonen, B., Varieties without extra automorphisms, II: Hyperelliptic curves, Math.Res. Lett. 7 (2000), 7782.CrossRefGoogle Scholar
[22] Ribes, L. and Zalesskii, P., Profinite Groups, Ergeb. Math. Grenzgeb. (3) 40, Springer, Berlin, 2000.Google Scholar
[23] Serre, J. P. and Tate, J., Good reduction of abelian varieties, Ann. of Math. (2) 88 (1968), 492517.CrossRefGoogle Scholar
[24] Takao, N., Braid monodromies on proper curves and pro-l Galois representations, preprint, to appear in J. Inst. Math. Jussieu.Google Scholar
[25] Tamagawa, A., The Grothendieck conjecture for affine curves, Compos. Math. 109 (1997), 135194.CrossRefGoogle Scholar
[26] Tamagawa, A., Resolution of nonsingularities of families of curves, Publ. Res. Inst. Math. Sci. 40 (2004), 12911336.Google Scholar