[Arcs et coins sur une singularité rationnelle de surface]
Soit une singularité rationnelle de surface sur un corps algébriquement clos k de caractéristique 0, soit une valuation divisorielle essentielle sur , et le point stable de lʼespace des arcs qui correspond à . On démontre que tout coin centré en se relève à la désingularisation minimale. Cela démontre le problème de Nash pour les singularités rationnelles de surface, et réduit le problème de Nash pour les surfaces aux singularités quasi-rationnelles qui ne sont pas rationnelles. En caractéristique positive, on donne un contre-exemple au problème de relèvement de k-coins pour une surface dont lʼapplication de Nash est bijective.
Let be a rational surface singularity over an algebraically closed field k of characteristic 0, let be an essential divisorial valuation over , and the stable point of the space of arcs corresponding to . We prove that any wedge centered at lifts to the minimal desingularization. This proves the Nash problem for rational surface singularities, and reduces the Nash problem for surfaces to quasirational normal singularities which are not rational. In positive characteristic, we give a counterexample to the k-wedge lifting problem for a surface for which the Nash map is bijective.
Accepté le :
Publié le :
Ana J. Reguera 1
@article{CRMATH_2011__349_19-20_1083_0, author = {Ana J. Reguera}, title = {Arcs and wedges on rational surface singularities}, journal = {Comptes Rendus. Math\'ematique}, pages = {1083--1087}, publisher = {Elsevier}, volume = {349}, number = {19-20}, year = {2011}, doi = {10.1016/j.crma.2011.08.022}, language = {en}, }
Ana J. Reguera. Arcs and wedges on rational surface singularities. Comptes Rendus. Mathématique, Volume 349 (2011) no. 19-20, pp. 1083-1087. doi : 10.1016/j.crma.2011.08.022. https://comptes-rendus.academie-sciences.fr/mathematique/articles/10.1016/j.crma.2011.08.022/
[1] On isolated rational singularities of surfaces, Amer. J. Math., Volume 88 (1966), pp. 129-136
[2] Rationale Singularitäten komplexer Flächen, Inv. Math., Volume 4 (1968), pp. 336-358
[3] Singularities of Plane Curves, London Math. Soc. Lecture Note, vol. 276, Cambridge University Press, 2000
[4] On rational singularities, Amer. J. Math., Volume 94 (1972), pp. 597-608
[5] Arcs and wedges on sandwiched surface singularities, Amer. J. Math., Volume 121 (1999), pp. 1191-1213
[6] M. Lejeune-Jalabert, A. Reguera, Exceptional divisors which are nor uniruled belong to the image of the Nash map, (2008), J. Inst. Math. Jussieu, in press. | arXiv
[7] Universal Abelian covers of certain surface singularities, Math. Ann., Volume 334 (2006), pp. 753-773
[8] A curve selection lemma in spaces of arcs and the image of the Nash map, Compositio Math., Volume 142 (2006), pp. 119-130
[9] Towards the singular locus of the space of arcs, Amer. J. Math., Volume 131 (2009) no. 2, pp. 313-350
Cité par Sources :
Commentaires - Politique