19 citations · 118 across the 23 of their papers we have counts for
12 papers · 1 filter
Periodic symplectic and Hamiltonian diffeomorphisms on irrational ruled surfaces
Nicholas Lindsay, Weiyi Zhang
We investigate when finite-order Hamiltonian diffeomorphisms extend to Hamiltonian circle actions, probing the transition from discrete to continuous symmetry in symplectic topolog…
Symplectic blowing down in dimension Six
Tian-Jun Li, Yongbin Ruan, Weiyi Zhang
We establish a blowing down criterion in the context of birational symplectic geometry in dimension 6.
Moduli space of -holomorphic subvarieties
Weiyi Zhang
We study the moduli space of -holomorphic subvarieties in a -dimensional symplectic manifold. For an arbitrary tamed almost complex structure, we show that the moduli space o…
The curve cone of almost complex 4-manifolds
Weiyi Zhang
In this paper, we study the curve cone of an almost complex -manifold which is tamed by a symplectic form. In particular, we prove the cone theorem as in Mori theory for all suc…
J-holomorphic curves in a nef class
Tian-Jun Li, Weiyi Zhang
Taubes established fundamental properties of holomorphic subvarieties in dimension 4 in \cite{T1}. In this paper, we further investigate properties of reducible holomorphic…
Almost Kahler forms on rational 4-manifolds
Tian-Jun Li, Weiyi Zhang
We study Nakai-Moishezon type question and Donaldson's "tamed to compatible" question for almost complex structures on rational four manifolds. By extending Taubes' subvarieties--c…
A note on exact forms on almost complex manifolds
Tedi Draghici, Weiyi Zhang
Reformulations of Donaldson's "tamed to compatible" question are obtained in terms of spaces of exact forms on a compact almost complex manifold . In dimension 4, we sh…
On the J-anti-invariant cohomology of almost complex 4-manifolds
Tedi Draghici, Tian-Jun Li, Weiyi Zhang
For a compact almost complex 4-manifold , we study the subgroups of consisting of cohomology classes representable by -invariant, respect…
Additivity and Relative Kodaira Dimensions
Tian-Jun Li, Weiyi Zhang
In this paper we introduce the notion of relative Kodaira dimension for a symplectic 4-manifold M with a possibly disconnected embedded symplectic surface F. One notable feature is…
Symplectic forms and cohomology decomposition of almost complex 4-manifolds
Tedi Draghici, Tian-Jun Li, Weiyi Zhang
For any compact almost complex manifold , the last two authors defined two subgroups , of the degree 2 real de Rham cohomology group $H^2(M, \mathbb{R})…
The Kodaira Dimension of Lefschetz Fibrations
Josef G Dorfmeister, Weiyi Zhang
In this note, we verify that the complex Kodaira dimension equals the symplectic Kodaira dimension for smooth 4-manifolds with complex and symplectic structures. We als…
Comparing tamed and compatible symplectic cones and cohomological properties of almost complex manifolds
Tian-Jun Li, Weiyi Zhang
We introduce certain homology and cohomology subgroups for any almost complex structure and study their pureness, fullness and duality properties. Motivated by a question of Donald…