irreducible 3-manifold

《Chromatic Homotopy Theory》 · 第 276 页 · Section 9.2.3，Definition 9.2.7 及其上下文

Let \(M\) be a connected, oriented 3-manifold with (possibly empty) boundary. The manifold \(M\) is irreducible if every sphere \(S\subset\operatorname{int}(M)\) bounds a ball. It is important to recall here that the sphere must be a smooth surface.