We deal with a reducible projective surface with so-called Zappatic singularities, which are a generalization of normal crossings. First we compute the -genus of , i.e. the dimension of the vector space of global sections of the dualizing sheaf . Then we prove that, when is smoothable, i.e. when is the central fibre of a flat family parametrized by a disc, with smooth general fibre, then the -genus of the fibres of is constant.
Nous étudions une surface projective réductible avec des singularités dites Zappatiques, qui sont une généralisation des croisements normaux. Nous calculons d’abord le -genre de , c’est-à-dire la dimension de l’espace vectoriel des sections globales du faisceau dualisant sur . Nous démontrons après que, si est lissifiable, c’est-à-dire si est la fibre centrale d’une famille plate paramétrée par un disque, à fibre générale lisse, alors le -genre des fibres est constant.
Accepted:
DOI: 10.5802/aif.2266
Classification: 14J17, 14B07, 14D06, 14D07, 14N20
Keywords: Degenerations of surfaces, singularities, birational geometry, topological invariants
@article{AIF_2007__57_2_491_0, author = {Calabri, Alberto and Ciliberto, Ciro and Flamini, Flaminio and Miranda, Rick}, title = {On the genus of reducible surfaces and degenerations of surfaces}, journal = {Annales de l'Institut Fourier}, pages = {491--516}, publisher = {Association des Annales de l{\textquoteright}institut Fourier}, volume = {57}, number = {2}, year = {2007}, doi = {10.5802/aif.2266}, zbl = {1125.14018}, mrnumber = {2310949}, language = {en}, url = {https://aif.centre-mersenne.org/articles/10.5802/aif.2266/} }
TY - JOUR TI - On the genus of reducible surfaces and degenerations of surfaces JO - Annales de l'Institut Fourier PY - 2007 DA - 2007/// SP - 491 EP - 516 VL - 57 IS - 2 PB - Association des Annales de l’institut Fourier UR - https://aif.centre-mersenne.org/articles/10.5802/aif.2266/ UR - https://zbmath.org/?q=an%3A1125.14018 UR - https://www.ams.org/mathscinet-getitem?mr=2310949 UR - https://doi.org/10.5802/aif.2266 DO - 10.5802/aif.2266 LA - en ID - AIF_2007__57_2_491_0 ER -
Calabri, Alberto; Ciliberto, Ciro; Flamini, Flaminio; Miranda, Rick. On the genus of reducible surfaces and degenerations of surfaces. Annales de l'Institut Fourier, Volume 57 (2007) no. 2, pp. 491-516. doi : 10.5802/aif.2266. https://aif.centre-mersenne.org/articles/10.5802/aif.2266/
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