Article contents
Automorphisms of blowups of threefolds being Fano or having Picard number 1
Published online by Cambridge University Press: 12 May 2016
Abstract
Let $X_{0}$ be a smooth projective threefold which is Fano or which has Picard number 1. Let
$\unicode[STIX]{x1D70B}:X\rightarrow X_{0}$ be a finite composition of blowups along smooth centers. We show that for ‘almost all’ of such
$X$, if
$f\in \text{Aut}(X)$, then its first and second dynamical degrees are the same. We also construct many examples of blowups
$X\rightarrow X_{0}$, on which any automorphism is of zero entropy. The main idea is that, because of the log-concavity of dynamical degrees and the invariance of Chern classes under holomorphic automorphisms, there are some constraints on the nef cohomology classes. We will also discuss a possible application of these results to a threefold constructed by Kenji Ueno.
- Type
- Research Article
- Information
- Copyright
- © Cambridge University Press, 2016
References
![](https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20170905081843901-0878:S0143385716000043:S0143385716000043_inline6.gif?pub-status=live)
- 1
- Cited by