3 papers
math.AG2025
Nonrational varieties with unirational parametrizations of coprime degrees
Song Yang, Xun Yu, Zigang Zhu
We show that there exists a -dimensional family of smooth cubic threefolds admitting unirational parametrizations of coprime degrees. This together with Clemens--Griffiths' work…
math.AG2024
On automorphism groups of smooth hypersurfaces
Song Yang, Xun Yu, Zigang Zhu
We show that smooth hypersurfaces in complex projective spaces with automorphism groups of maximum size are isomorphic to Fermat hypersurfaces, with a few exceptions. For the excep…
math.AG2023
Automorphism groups of cubic fivefolds and fourfolds
Song Yang, Xun Yu, Zigang Zhu
In this paper, we introduce notions of partitionability and characteristic sets of homogeneous polynomials and give a complete classification of groups faithfully acting on smooth…