Weak convergence of weak derivative implies strong convergence












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$begingroup$


Note that here both $w_n$ and $phi_n$ are vector functions.



The following is given :
$ w_n rightarrow w$ weakly in $ L^q(B; {mathbb{R}}^M)$
& ${curl[w]}_{n=1}^{infty}$ is precompact in $ W^{-1,s}(B; R^{M times M})$ for a certain $ s>1$.



Also, it is assumed that $ w_n = nabla _xphi_n$ where $int_{mathbb{R}^M} phi_n dy =0$.



Then using the Sobolev embedding theorem, that by compactness, it is concluded that $phi_n rightarrow phi$ strongly in $ L^q(mathbb{R}^M)$.



My question is how can the above conclusion be made? How can we conclude that $ phi_n in L^q(mathbb{R}^M)$ ?



(Source - Mathematical theory of compressible viscous fluids by Feireisl. The above occurs in the proof of Div Curl lemma for a special case)










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$endgroup$

















    0












    $begingroup$


    Note that here both $w_n$ and $phi_n$ are vector functions.



    The following is given :
    $ w_n rightarrow w$ weakly in $ L^q(B; {mathbb{R}}^M)$
    & ${curl[w]}_{n=1}^{infty}$ is precompact in $ W^{-1,s}(B; R^{M times M})$ for a certain $ s>1$.



    Also, it is assumed that $ w_n = nabla _xphi_n$ where $int_{mathbb{R}^M} phi_n dy =0$.



    Then using the Sobolev embedding theorem, that by compactness, it is concluded that $phi_n rightarrow phi$ strongly in $ L^q(mathbb{R}^M)$.



    My question is how can the above conclusion be made? How can we conclude that $ phi_n in L^q(mathbb{R}^M)$ ?



    (Source - Mathematical theory of compressible viscous fluids by Feireisl. The above occurs in the proof of Div Curl lemma for a special case)










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      Note that here both $w_n$ and $phi_n$ are vector functions.



      The following is given :
      $ w_n rightarrow w$ weakly in $ L^q(B; {mathbb{R}}^M)$
      & ${curl[w]}_{n=1}^{infty}$ is precompact in $ W^{-1,s}(B; R^{M times M})$ for a certain $ s>1$.



      Also, it is assumed that $ w_n = nabla _xphi_n$ where $int_{mathbb{R}^M} phi_n dy =0$.



      Then using the Sobolev embedding theorem, that by compactness, it is concluded that $phi_n rightarrow phi$ strongly in $ L^q(mathbb{R}^M)$.



      My question is how can the above conclusion be made? How can we conclude that $ phi_n in L^q(mathbb{R}^M)$ ?



      (Source - Mathematical theory of compressible viscous fluids by Feireisl. The above occurs in the proof of Div Curl lemma for a special case)










      share|cite|improve this question











      $endgroup$




      Note that here both $w_n$ and $phi_n$ are vector functions.



      The following is given :
      $ w_n rightarrow w$ weakly in $ L^q(B; {mathbb{R}}^M)$
      & ${curl[w]}_{n=1}^{infty}$ is precompact in $ W^{-1,s}(B; R^{M times M})$ for a certain $ s>1$.



      Also, it is assumed that $ w_n = nabla _xphi_n$ where $int_{mathbb{R}^M} phi_n dy =0$.



      Then using the Sobolev embedding theorem, that by compactness, it is concluded that $phi_n rightarrow phi$ strongly in $ L^q(mathbb{R}^M)$.



      My question is how can the above conclusion be made? How can we conclude that $ phi_n in L^q(mathbb{R}^M)$ ?



      (Source - Mathematical theory of compressible viscous fluids by Feireisl. The above occurs in the proof of Div Curl lemma for a special case)







      real-analysis functional-analysis derivatives sobolev-spaces






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      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Dec 10 '18 at 19:09







      Erm20

















      asked Dec 10 '18 at 18:35









      Erm20Erm20

      355311




      355311






















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