integral equation and Fourier transform of “almost” the convolution












0












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I am facing an integral equation where one of the terms looks like this:



$$ V(t) = int_t^{+infty} K(x-t) cdot V(x) , dx $$



where $$K(x) = N(frac{-b-asigma^2}{sigma sqrt{x}}) - d^{-2a}N(frac{-b+asigma^2}{sigma sqrt{x}}) $$ and $N(cdot)$ is the cumulative normal distribution. I am inclined to use the Convolution theorem, but the term inside of the $K$ has flipped signs. Also, looking at the formula for $K$ it is not even (nor odd) since its not defined for $x<0$ (Look at the square root term). Any suggestions as to how to make use of the Convolution theorem or any other better way?










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  • $begingroup$
    With $U(t)= V(-t)$ it is $U = U ast K 1_{x > 0}$ which can be Fourier transformed
    $endgroup$
    – reuns
    Dec 2 '18 at 0:58












  • $begingroup$
    @reuns thank you! I think that is what I'm looking for. I would accept it an an answer
    $endgroup$
    – dleal
    Dec 2 '18 at 1:13
















0












$begingroup$


I am facing an integral equation where one of the terms looks like this:



$$ V(t) = int_t^{+infty} K(x-t) cdot V(x) , dx $$



where $$K(x) = N(frac{-b-asigma^2}{sigma sqrt{x}}) - d^{-2a}N(frac{-b+asigma^2}{sigma sqrt{x}}) $$ and $N(cdot)$ is the cumulative normal distribution. I am inclined to use the Convolution theorem, but the term inside of the $K$ has flipped signs. Also, looking at the formula for $K$ it is not even (nor odd) since its not defined for $x<0$ (Look at the square root term). Any suggestions as to how to make use of the Convolution theorem or any other better way?










share|cite|improve this question









$endgroup$












  • $begingroup$
    With $U(t)= V(-t)$ it is $U = U ast K 1_{x > 0}$ which can be Fourier transformed
    $endgroup$
    – reuns
    Dec 2 '18 at 0:58












  • $begingroup$
    @reuns thank you! I think that is what I'm looking for. I would accept it an an answer
    $endgroup$
    – dleal
    Dec 2 '18 at 1:13














0












0








0





$begingroup$


I am facing an integral equation where one of the terms looks like this:



$$ V(t) = int_t^{+infty} K(x-t) cdot V(x) , dx $$



where $$K(x) = N(frac{-b-asigma^2}{sigma sqrt{x}}) - d^{-2a}N(frac{-b+asigma^2}{sigma sqrt{x}}) $$ and $N(cdot)$ is the cumulative normal distribution. I am inclined to use the Convolution theorem, but the term inside of the $K$ has flipped signs. Also, looking at the formula for $K$ it is not even (nor odd) since its not defined for $x<0$ (Look at the square root term). Any suggestions as to how to make use of the Convolution theorem or any other better way?










share|cite|improve this question









$endgroup$




I am facing an integral equation where one of the terms looks like this:



$$ V(t) = int_t^{+infty} K(x-t) cdot V(x) , dx $$



where $$K(x) = N(frac{-b-asigma^2}{sigma sqrt{x}}) - d^{-2a}N(frac{-b+asigma^2}{sigma sqrt{x}}) $$ and $N(cdot)$ is the cumulative normal distribution. I am inclined to use the Convolution theorem, but the term inside of the $K$ has flipped signs. Also, looking at the formula for $K$ it is not even (nor odd) since its not defined for $x<0$ (Look at the square root term). Any suggestions as to how to make use of the Convolution theorem or any other better way?







fourier-transform integral-equations






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share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 2 '18 at 0:36









dlealdleal

8710




8710












  • $begingroup$
    With $U(t)= V(-t)$ it is $U = U ast K 1_{x > 0}$ which can be Fourier transformed
    $endgroup$
    – reuns
    Dec 2 '18 at 0:58












  • $begingroup$
    @reuns thank you! I think that is what I'm looking for. I would accept it an an answer
    $endgroup$
    – dleal
    Dec 2 '18 at 1:13


















  • $begingroup$
    With $U(t)= V(-t)$ it is $U = U ast K 1_{x > 0}$ which can be Fourier transformed
    $endgroup$
    – reuns
    Dec 2 '18 at 0:58












  • $begingroup$
    @reuns thank you! I think that is what I'm looking for. I would accept it an an answer
    $endgroup$
    – dleal
    Dec 2 '18 at 1:13
















$begingroup$
With $U(t)= V(-t)$ it is $U = U ast K 1_{x > 0}$ which can be Fourier transformed
$endgroup$
– reuns
Dec 2 '18 at 0:58






$begingroup$
With $U(t)= V(-t)$ it is $U = U ast K 1_{x > 0}$ which can be Fourier transformed
$endgroup$
– reuns
Dec 2 '18 at 0:58














$begingroup$
@reuns thank you! I think that is what I'm looking for. I would accept it an an answer
$endgroup$
– dleal
Dec 2 '18 at 1:13




$begingroup$
@reuns thank you! I think that is what I'm looking for. I would accept it an an answer
$endgroup$
– dleal
Dec 2 '18 at 1:13










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