8 papers
Weierstrass models
Ying Zong
Elliptic K3 admit contraction to plane models, the Weierstrass models. We define a higher dimensional notion of Weierstrass models, show that they are compactification of torsors i…
Minimal models of L*
Ying Zong
Let S be an algebraic space, A an S-abelian algebraic space, L an S-fiberwise numerically trivial invertible module on A, and L* the sheaf of regular sections of L considered as a…
Equidimensionality and regularity
Ying Zong
The existence of an equidimensional morphism f with etale local sections from a regular algebraic space X to a locally noetherian normal algebraic space S of characteristic zero wi…
Group schemes of square free order
V. Kumar Murty, Ying Zong
Every finite flat finitely presented group scheme G of square free order over a scheme S can be written as an extension of a finite etale S-group scheme G" by a commutative finite…
Basic finite étale equivalence relations
Ying Zong
We characterize quotient of a non-degenerate abelian fibration by a finite étale equivalence relation. We show that non-uniruled degenerations of each such quotient tend to be almo…
Almost non-degenerate abelian fibrations
Ying Zong
We provide evidence for the Principle : Non-uniruled abelian fibrations are almost non-degenerate.
A going-up theorem
Ying Zong
We generalize certain arguments in Zariski's irregularity theorem on cyclic multiple planes.
Elliptic minuscule pairs and splitting abelian varieties
V. Kumar Murty, Ying Zong
We partially answer, in terms of monodromy, Murty and Patankar's question: Given an absolutely simple abelian variety over a number field, does it have simple specializations at a…