On complex surfaces with 5 or 6 semistable singular fibers over ℙ1
On complex surfaces with 5 or 6 semistable singular fibers over ℙ1
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DOI:
10.1007/s00209-004-0706-4
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发表时间:
2004-01
影响因子:
0.8
通讯作者:
Shengli Tan;Yuping Tu;A. Zamora
中科院分区:
文献类型:
--
作者:
Shengli Tan;Yuping Tu;A. Zamora
Letbe a fibered surface with fibers of genus g>1. If f is semistable and non isotrivial we prove that X of non negative Kodaira dimension implies that the number s of singular fibers is at least 5. Information about the nature of X if s=6,5 and g<6 is given. If f is any relatively minimal fibration we bound by below K_f^2, the bound depending on g and the Kodaira dimension of X, a classification of rational surfaces with minimal K_f^2 is given. Moreover, we prove several properties of positivity for the linear system K_X+F (F a fibre of f). Examples of a K3 surfaces admitting a semistable fibration with s=6 and g=3 and of a surface of general type admitting a semistable fibration with s=7 and g=4 are provided.