Let $\Omega$ be an open set of the $\Bbb R$
-As usual denotes by $H_0^1(\Omega)$ the closure of $C_c^\infty(\Omega)$ in $H^1(\Omega)$
-Consider $H_*(\Omega)$ the closure of $C_c^\infty(\Omega)$ in $H^1(\Bbb R^d)$.
-Consider $H_{\Omega}(\Omega)=\{u\in H^1(\Bbb R^d) \text{ u= 0 a.e on } \Omega^c\}$.
Question does the above spaces coincide? If not when are they equal?