Support of a fundamental solution of wave equation












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I need to prove that the following fundamental solution of the wave equation:
$$ E(x,t)= mathfrak{F}^{-1}Bigg(frac{sin ( t|.|)}{|.|}Bigg)frac{theta(t)}{(2pi)^{n/2}}(x) in mathcal{S}'(mathbb{R}^{1,n})$$
satisfies:
$$ supp(E) subset { (t,x) in mathbb{R}^{1,n}: |x| leq t}$$
(where $mathfrak{F}^{-1}$ - inverse Fourie transform wrt. "spatial" coordinates).



It is also hinted that Paley-Wiener-Schwartz theorem is used in this.



I have found a theorem that states the following:




Let $u in mathcal{D}'(mathbb{R}^n)$ and $f in C^infty(mathbb{R}^n)$. If $fu=0$ then $$ supp(u) subset { xin mathbb{R}^n | f(x)=0} $$




Is this theorem somehow applicable here?










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$endgroup$

















    1












    $begingroup$


    I need to prove that the following fundamental solution of the wave equation:
    $$ E(x,t)= mathfrak{F}^{-1}Bigg(frac{sin ( t|.|)}{|.|}Bigg)frac{theta(t)}{(2pi)^{n/2}}(x) in mathcal{S}'(mathbb{R}^{1,n})$$
    satisfies:
    $$ supp(E) subset { (t,x) in mathbb{R}^{1,n}: |x| leq t}$$
    (where $mathfrak{F}^{-1}$ - inverse Fourie transform wrt. "spatial" coordinates).



    It is also hinted that Paley-Wiener-Schwartz theorem is used in this.



    I have found a theorem that states the following:




    Let $u in mathcal{D}'(mathbb{R}^n)$ and $f in C^infty(mathbb{R}^n)$. If $fu=0$ then $$ supp(u) subset { xin mathbb{R}^n | f(x)=0} $$




    Is this theorem somehow applicable here?










    share|cite|improve this question











    $endgroup$















      1












      1








      1


      1



      $begingroup$


      I need to prove that the following fundamental solution of the wave equation:
      $$ E(x,t)= mathfrak{F}^{-1}Bigg(frac{sin ( t|.|)}{|.|}Bigg)frac{theta(t)}{(2pi)^{n/2}}(x) in mathcal{S}'(mathbb{R}^{1,n})$$
      satisfies:
      $$ supp(E) subset { (t,x) in mathbb{R}^{1,n}: |x| leq t}$$
      (where $mathfrak{F}^{-1}$ - inverse Fourie transform wrt. "spatial" coordinates).



      It is also hinted that Paley-Wiener-Schwartz theorem is used in this.



      I have found a theorem that states the following:




      Let $u in mathcal{D}'(mathbb{R}^n)$ and $f in C^infty(mathbb{R}^n)$. If $fu=0$ then $$ supp(u) subset { xin mathbb{R}^n | f(x)=0} $$




      Is this theorem somehow applicable here?










      share|cite|improve this question











      $endgroup$




      I need to prove that the following fundamental solution of the wave equation:
      $$ E(x,t)= mathfrak{F}^{-1}Bigg(frac{sin ( t|.|)}{|.|}Bigg)frac{theta(t)}{(2pi)^{n/2}}(x) in mathcal{S}'(mathbb{R}^{1,n})$$
      satisfies:
      $$ supp(E) subset { (t,x) in mathbb{R}^{1,n}: |x| leq t}$$
      (where $mathfrak{F}^{-1}$ - inverse Fourie transform wrt. "spatial" coordinates).



      It is also hinted that Paley-Wiener-Schwartz theorem is used in this.



      I have found a theorem that states the following:




      Let $u in mathcal{D}'(mathbb{R}^n)$ and $f in C^infty(mathbb{R}^n)$. If $fu=0$ then $$ supp(u) subset { xin mathbb{R}^n | f(x)=0} $$




      Is this theorem somehow applicable here?







      pde fourier-analysis harmonic-analysis






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Jan 14 at 17:35







      Sergey Dylda

















      asked Jan 14 at 17:24









      Sergey DyldaSergey Dylda

      1616




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