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 $(M,J)$, we study the subgroups $H_J^{\pm }$ of $H^2(M,\mathbb{R})$ consisting of cohomology classes representable by $J$-invariant, respect…