Nous donnons des détails sur la démonstration du second théorème de Fujita et nous montrons que l'image directe du fibré canonique relatif d'une fibration sur une courbe B est la somme directe d'un fibré vectoriel ample et d'un fibré vectoriel unitairement plat si l'espace total X est une variété kählérienne compacte. Nous montrons en outre que V n'est en général pas semi-ample, ce qui constitue notre résultat principal.
We provide details for the proof of Fujita's second theorem and prove that for a Kähler fibre space over a smooth projective curve B, the direct image of the relative dualizing sheaf is the direct sum of an ample and a unitary flat bundle. We also show that V needs not be semiample, which is our main result.
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@article{CRMATH_2014__352_3_241_0, author = {Catanese, Fabrizio and Dettweiler, Michael}, title = {The direct image of the relative dualizing sheaf needs not be semiample}, journal = {Comptes Rendus. Math\'ematique}, pages = {241--244}, publisher = {Elsevier}, volume = {352}, number = {3}, year = {2014}, doi = {10.1016/j.crma.2013.12.015}, language = {en}, url = {http://www.numdam.org/articles/10.1016/j.crma.2013.12.015/} }
TY - JOUR AU - Catanese, Fabrizio AU - Dettweiler, Michael TI - The direct image of the relative dualizing sheaf needs not be semiample JO - Comptes Rendus. Mathématique PY - 2014 SP - 241 EP - 244 VL - 352 IS - 3 PB - Elsevier UR - http://www.numdam.org/articles/10.1016/j.crma.2013.12.015/ DO - 10.1016/j.crma.2013.12.015 LA - en ID - CRMATH_2014__352_3_241_0 ER -
%0 Journal Article %A Catanese, Fabrizio %A Dettweiler, Michael %T The direct image of the relative dualizing sheaf needs not be semiample %J Comptes Rendus. Mathématique %D 2014 %P 241-244 %V 352 %N 3 %I Elsevier %U http://www.numdam.org/articles/10.1016/j.crma.2013.12.015/ %R 10.1016/j.crma.2013.12.015 %G en %F CRMATH_2014__352_3_241_0
Catanese, Fabrizio; Dettweiler, Michael. The direct image of the relative dualizing sheaf needs not be semiample. Comptes Rendus. Mathématique, Tome 352 (2014) no. 3, pp. 241-244. doi : 10.1016/j.crma.2013.12.015. http://www.numdam.org/articles/10.1016/j.crma.2013.12.015/
[1] Answer to a question by Fujita on variation of Hodge structures, 2013 (preprint, 26 pages) | arXiv
[2] Monodromy of hypergeometric functions and non-lattice integral monodromy, Publ. Math. IHÉS, Volume 63 (1986), pp. 5-89
[3] On Kähler fiber spaces over curves, J. Math. Soc. Jpn., Volume 30 (1978) no. 4, pp. 779-794
[4] The sheaf of relative canonical forms of a Kähler fiber space over a curve, Proc. Jpn. Acad., Ser. A, Math. Sci., Volume 54 (1978) no. 7, pp. 183-184
[5] Periods of integrals on algebraic manifolds. III. Some global differential-geometric properties of the period mapping, Publ. Math. IHÉS, Volume 38 (1970), pp. 125-180
[6] Topics in Transcendental Algebraic Geometry, Annals of Mathematics Studies, vol. 106, Princeton University Press, 1984
[7] Principles of Algebraic Geometry, Pure and Applied Mathematics, Wiley-Interscience, New York, 1978
[8] Recent developments in Hodge theory: A discussion of techniques and results, 1973 (1975), pp. 31-127
[9] Ample vector bundles on curves, Nagoya Math. J., Volume 43 (1971), pp. 73-89
[10] Classification of algebraic and analytic manifolds, Proc. Symp. Katata/Jap. (Ueno, Kenji, ed.) (Progress in Mathematics), Volume vol. 39, Birkhäuser, Boston, Mass. (1983), pp. 591-630 (Open problems: Classification of algebraic and analytic manifolds, 1982)
[11] Kodaira dimension of algebraic fiber spaces over curves, Invent. Math., Volume 66 (1982) no. 1, pp. 57-71
[12] Toroidal Embeddings, I, Lecture Notes in Mathematics, vol. 739, Springer, 1973 (viii+209 p)
[13] Global Analysis in Linear Differential Equations, Kluwer Academic Publishers, 1999
[14] Higher direct images of dualizing sheaves. I, II, Ann. Math. (2), Volume 123 (1986), pp. 11-42
[15] Positivity in algebraic geometry. II. Positivity for vector bundles, and multiplier ideals, Ergebnisse der Mathematik und ihrer Grenzgebiete. 3, vol. 49, Springer-Verlag, Berlin, 2004 (xviii+385 p)
[16] A criterion for flatness of Hodge bundles over curves and geometric applications, Math. Ann., Volume 268 (1984) no. 1, pp. 1-19
[17] Variation of Hodge structure: The singularities of the period mapping, Invent. Math., Volume 22 (1973), pp. 211-319
[18] Über diejenigen Fälle in welchen die Gaussische hypergeometrische Reihe eine algebraische Funktion ihres vierten Elements darstellt, J. Reine Angew. Math., Volume 75 (1873), pp. 292-335
[19] Hodge theory with degenerating coefficients: -cohomology in the Poincaré metric, Ann. Math. (2), Volume 109 (1979), pp. 415-476
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