Zhijia Zhang

activity

20242026

collaborators

12 papers

math.AG2026

Cohomological obstructions to equivariant unirationality

Yuri Tschinkel, Zhijia Zhang

We study cohomological obstructions to equivariant unirationality, with special regard to actions of finite groups on del Pezzo surfaces and Fano threefolds.

math.AG2026

Birational invariance of higher Amitsur groups

Federico Scavia, Yuri Tschinkel, Zhijia Zhang

Let $k$ be a field of characteristic zero and $G$ a finite group. We prove that for all $n \geq 2$ , the $n$ th Amitsur group is a stable $G$ -birational invariant of smooth projective…

math.AG2026

Birational geometry of actions on del Pezzo surfaces

Ivan Cheltsov, Yuri Tschinkel, Zhijia Zhang

We complete the classification of regular generically free actions of finite groups on del Pezzo surfaces, up to birational equivalence. As a byproduct, we settle several open prob…

math.AG2025

Equivariant geometry of singular cubic threefolds, II

Ivan Cheltsov, Lisa Marquand, Yuri Tschinkel +1

We study linearizability of actions of finite groups on cubic threefolds with nonnodal isolated singularities.

math.AG2025

Equivariant unirationality of tori in small dimensions

Yuri Tschinkel, Zhijia Zhang

We study equivariant unirationality of actions of finite groups on tori of small dimensions.

math.AG2025

Conjugacy classes of linear actions in the plane Cremona group

Ivan Cheltsov, Yuri Tschinkel, Zhijia Zhang

We classify regular generically free actions of finite groups on the projective plane, up to conjugation in the Cremona group.