Let \(k\in \mathbb{N}\) and \(\Omega\subset \mathbb{R}^n\) be a domain. The Sobolev space \(W^{k,2}(\Omega)\) is often denoted by \(H^k(\Omega)\), because it is a Hilbert space .
Let \(k\in \mathbb{N}\) and \(\Omega\subset \mathbb{R}^n\) be a domain. The Sobolev space \(W^{k,2}(\Omega)\) is often denoted by \(H^k(\Omega)\), because it is a Hilbert space .