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arXiv 1605.04763math.AG
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非双有理于数值Calabi--Yau对的锥丛

Conic bundles that are not birational to numerical Calabi--Yau pairs

János Kollár

AI总结:

本文证明了一般锥丛(分支曲线次数≥19)不双有理于任何具有有效反典范除子倍数的正规射影簇,并给出数域上的二维例子。

摘要:

设$X$是射影平面上的一个一般锥丛,其分支曲线次数至少为19。我们证明不存在与$X$双有理的正规射影簇$Y$,使得其反典范除子的某个倍数有效。我们还给出了定义在数域上的二维锥丛的此类例子。

英文摘要:

Let $X$ be a general conic bundle over the projective plane with branch curve of degree at least 19. We prove that there is no normal projective variety $Y$ that is birational to $X$ and such that some multiple of its anticanonical divisor is effective. We also give such examples for 2-dimensional conic bundles defined over a number field.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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