Whitney’s trick for three $2$-dimensional homology classes of $4$-manifolds
Masayuki Yamasaki · Proceedings of the American Mathematical Society · 1979
In his recent paper, Y. Matsumoto has defined a triple product of 2-homology classes of simply-connected oriented 4-manifolds, when the intersection numbers are zero. In the present paper, the author establishes that three 2-homology classes can be homotopically separated if the intersection numbers and the triple product vanish.