I'm reading the book Geometry of Four Manifolds by Donaldson. In page 179, he mentions that:
There exist a homotopy equivalent $\Omega^n(BSU(2))\cong \Omega^{n-1}(SU(2))$. Here $\Omega^m(X)$ means the mapping space $Map(S^m, X)$ with compact open topology.
The book wrote that it is because bundles over $S^n$ are determined by clutching fuction.
I know the correspondence above give a map from $\Omega^{n-1}(SU(2))\to \Omega^n(BSU(2))$. However seems it is not directly that this map indeed a homotopy equivalent, I try to prove it but I even have no idea to prove the map is continuous, can anyone help me? Thanks!