Connecting Lemmas and Representing Homology Classes of Simply Connected 4-Manifolds
Akira Yasuhara · Tokyo Journal of Mathematics · 1996
We consider surfaces in simply connected 4-manifolds. We estimate the normal Euler numbers of bounded non-orientable surfaces and consider the problem of representing characteristic homology classes by orientable surfaces. To do so, we develop techniques connecting the above problems for given surfaces with the problems for surfaces with fewer first Betti numbers.