Knotted contractible 4-manifolds in the 4-sphere

2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/61939Examples are given to show that some compact contractible 4-manifolds can be knotted in the 4-sphere. It is then proved that any finitely presented perfect group with a balanced presentation is a knot group for an embedding of some contractible 4-manifold in the 4-sphere.Six pages with two figuresGeometric TopologyPrimary 57Q45; Secondary 57M20, 57M2Knotted contractible 4-manifolds in the 4-spheretext