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On non-liftable Calabi-Yau threefolds

Torsten Ekedahl
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Abstract

Only two ways to construct non-liftable Calabi-Yau threefolds are currently known, one example by Hirokado and one method of Schröer. This article computes some cohomological invariants of these examples of non-liftable Calabi-Yau threefolds, in particular it computes their mini-versal deformations. One conclusion is that their mixed characteristic mini-versal deformation spaces are actually smooth over the characteristic $p$ base field. Furthermore, a new family, constructed in the spirit of Schröer, is introduced and the same calculations are performed for it.

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Torsten Ekedahl. 2004-05-26. On non-liftable Calabi-Yau threefolds. https://arxiv.org/abs/math/0306435

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