On a $PL$ embedded 2-sphere in 4-manifold
On a $PL$ embedded 2-sphere in 4-manifold
Let M^{2n} be a simply connected differentiable manifold, and let \xi\in\pi_{n}(M^{2n}) be a given homotopy class of maps S^{n}arrow M^{2n} .It is known that if n>2 , the class \xi can be represented\backslash by a differentiable imbedding f:S^{n}arrow M^{2n} .This follows from a reasoning similar to the one used by …