Semibundle decomposition of 3-manifolds and the twisted cofundamental group
The author considers a semibundle decomposition of a closed, oriented 3-manifold \(M\) such that \(M=M_1\cup M_2\), \(M_1\cap M_2=\Sigma\) is an embedded, orientable surface, and each \(M_i\) is a twisted \(I\)-bundle over a closed, nonorientable surface, with \(\Sigma\) the corresponding 0-sphere bundle. He defined twisted cofundamental group and constructed an isomorphism between the twisted cofundamental group and a certain one-dimensional cohomology group with twisted integer coefficients and formulated a Stallings' fibration theorem for semibundles.
scientific article; zbMATH DE number 1071476
scientific article