Calabi-Yau threefolds of quotient type

K. Oguiso; J. Sakurai

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arXiv · math/9909175

Calabi-Yau threefolds of quotient type

K. Oguiso·J. Sakurai

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Abstract

First, we classify Calabi-Yau threefolds with infinite fundamental group by means of their minimal splitting coverings introduced by Beauville, and deduce that the nef cone is a rational simplicial cone and any rational nef divisor is semi-ample if the second Chern class is identically zero. We also derive a sufficient condition for the fundamental group to be finite in terms of the Picard number in an optimal form. Next, we give a concrete structure Theorem concerning $c_{2}$-contractions of Calabi-Yau threefolds as a generalisation and also a correction of our earlier works for simply connected ones. Finally, as an application, we show the finiteness of the isomorphism classes of $c_{2}$-contractions of each Calabi-Yau threefold.

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BibTeX RIS

K. Oguiso, J. Sakurai. 1999-09-29. Calabi-Yau threefolds of quotient type. https://arxiv.org/abs/math/9909175

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