Lei Zhang

collaborators

3 papers

math.AG2026

Geometric singularities of regular surfaces with nef anti-canonical divisors over imperfect fields

Chongning Wang, Lei Zhang

We prove that a regular projective surface $S$ over a field $k$ of characteristic $p \geq 7$ , with $H^{0} (S, O_{S}) = k$ and $- K_{S}$ being nef, is geometrically integral over $k…

math.AG2026

On canonical bundle formula for fibrations of curves with arithmetic genus one

Jingshan Chen, Chongning Wang, Lei Zhang

In this paper, we develop canonical bundle formulas for fibrations of relative dimension one in characteristic $p > 0$ . For such a fibration from a log pair $f : (X, I^) \to S$ ,…

math.AG2025

Irregular threefolds with numerically trivial canonical divisor

Jingshan Chen, Chongning Wang, Lei Zhang

In this paper, we classify irregular threefolds with numerically trivial canonical divisors in positive characteristic. For such a variety, if its Albanese dimension is not maximal…