caa a22 4500 475738438 CHVBK 20180406123453.0 cr unu---uuuuu 170329e20000701xx s 000 0 fre 10.1007/s002220000071 doi (NATIONALLICENCE)springer-10.1007/s002220000071 Déformations formelles des revêtements sauvagement ramifiés de courbes algébriques [Elektronische Daten] [José Bertin, Ariane Mézard] Abstract. : In this paper we study formal moduli for wildly ramified Galois covering. We prove a local-global principle. We then focus on the infinitesimal deformations of the Z/p Z-covers. We explicitly compute a deformation of an automorphism of order p which implies a universal obstruction for p>2. By deforming Artin-Schreier equations we obtain a lower bound on the dimension of the local versal deformation ring. At last, by comparing the global versal deformation ring to the complete local ring in a point of a moduli space, we determine the dimensions of the global and local versal deformation rings. Springer-Verlag Berlin Heidelberg, 2000 Bertin José Université de Grenoble I, Institut Fourier, UMR 5582 CNRS-UJF, UFR de Mathématiques, B.P. 74, 38402 Saint-Martin d'Hères Cedex, France (e-mail: {jose.bertin,ariane.mezard}@ujf-grenoble.fr), France aut Mézard Ariane Université de Grenoble I, Institut Fourier, UMR 5582 CNRS-UJF, UFR de Mathématiques, B.P. 74, 38402 Saint-Martin d'Hères Cedex, France (e-mail: {jose.bertin,ariane.mezard}@ujf-grenoble.fr), France aut Inventiones mathematicae Springer Berlin Heidelberg 141/1(2000-07-01), 195-238 0020-9910 141:1<195 2000 141 222 https://doi.org/10.1007/s002220000071 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s002220000071 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bertin José Université de Grenoble I, Institut Fourier, UMR 5582 CNRS-UJF, UFR de Mathématiques, B.P. 74, 38402 Saint-Martin d'Hères Cedex, France (e-mail: {jose.bertin,ariane.mezard}@ujf-grenoble.fr), France aut NATIONALLICENCE 700 1- Mézard Ariane Université de Grenoble I, Institut Fourier, UMR 5582 CNRS-UJF, UFR de Mathématiques, B.P. 74, 38402 Saint-Martin d'Hères Cedex, France (e-mail: {jose.bertin,ariane.mezard}@ujf-grenoble.fr), France aut NATIONALLICENCE 773 0- Inventiones mathematicae Springer Berlin Heidelberg 141/1(2000-07-01), 195-238 0020-9910 141:1<195 2000 141 222 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer