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Guy Fsone
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Possible way to define $H_0^1(\Omega)$ Sobolev spaces

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?

Guy Fsone
  • 1.1k
  • 6
  • 20