[en] Let $Y$ admit a rectangular Lefschetz decomposition of its derived category,
and consider a cyclic cover $X\to Y$ ramified over a divisor $Z$. In a setting
not considered by Kuznetsov and Perry, we define a subcategory $\mathcal{A}_Z$
of the equivariant derived category of $X$ which contains, rather than is
contained in, $\mathrm{D}^{\mathrm{b}}(Z)$. We then show that the equivariant
category of the Kuznetsov component of $X$ is decomposed into copies of
$\mathcal{A}_Z$. As an application, we relate $\mathcal{A}_Z$ with the cohomology of $Z$ under some numerical assumptions. In particular, we obtain a categorical Torelli theorem for the prime Fano threefolds of index 1 and genus 2.
Disciplines :
Mathematics
Author, co-author :
Dell, Hannah ✱
JACOVSKIS, Augustinas ✱; University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Mathematics (DMATH)
Rota, Franco ✱
✱ These authors have contributed equally to this work.
Language :
English
Title :
Cyclic covers: Hodge theory and categorical Torelli theorems