Bijective operator on a Hilbert space with unbounded inverse – math.stackexchange.com
Kiên Phùng Hữu
I want to find an example of a bijective operator on a Hilbert space $T : \mathfrak{H} \rightarrow \mathfrak{H} $ such that its inverse $T^{-1}$ is not bounded. I have seen examples of non-surjective ...