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In the HW section, the following equation was proposed:
[tex]ty(t)=\int_0^t \tau^{1-\alpha}y(t-\tau)d\tau;\quad \int_0^\infty y(x)dx=1[/tex]
Link to HW thread: https://www.physicsforums.com/showthread.php?t=97562
Using Laplace Transforms:
[tex]Y(p)=\mathcal{L}\left\{y(t)\right\}[/tex]
and noting the RHS is the inverse transform of a convolution, we obtain the IVP:
[tex]-Y^{'}=Y\frac{\Gamma(\alpha)}{p^\alpha};\quad Y(0)=\int_0^\infty e^{-0t}y(t)dt=1[/tex]
solving for [itex]\alpha \ne 1[/itex]:
[tex]Y(p)=Exp\left[-\frac{\Gamma(\alpha)}{1-\alpha}s^{1-\alpha}\right][/tex]
I (Mathematica) can invert this only for [itex]\alpha=1/2[/itex]:
[tex]y(t)=\frac{e^{-\pi/t}}{t^{3/2}}[/tex]
I'd like to know how to invert it for other values of alpha. My only recourse is to evaluate the complex contour for the inverse transform:
[tex]\frac{1}{2\pi i}\int_{\gamma-i\infty}^{\gamma+i\infty} Y(p)e^{pt}dp[/tex]
I'm not too good at this. I know I need to learn more about Complex Analysis and contours specifically, but for the time being, can someone help me through the integral for alpha=1/2:
[tex]\frac{1}{2\pi i}\int_{\gamma-i\infty}^{\gamma+i\infty} \frac{e^{st}}{e^{2\sqrt{\pi s}}}ds=\frac{e^{-\pi/t}}{t^{3/2}}[/tex]
[tex]ty(t)=\int_0^t \tau^{1-\alpha}y(t-\tau)d\tau;\quad \int_0^\infty y(x)dx=1[/tex]
Link to HW thread: https://www.physicsforums.com/showthread.php?t=97562
Using Laplace Transforms:
[tex]Y(p)=\mathcal{L}\left\{y(t)\right\}[/tex]
and noting the RHS is the inverse transform of a convolution, we obtain the IVP:
[tex]-Y^{'}=Y\frac{\Gamma(\alpha)}{p^\alpha};\quad Y(0)=\int_0^\infty e^{-0t}y(t)dt=1[/tex]
solving for [itex]\alpha \ne 1[/itex]:
[tex]Y(p)=Exp\left[-\frac{\Gamma(\alpha)}{1-\alpha}s^{1-\alpha}\right][/tex]
I (Mathematica) can invert this only for [itex]\alpha=1/2[/itex]:
[tex]y(t)=\frac{e^{-\pi/t}}{t^{3/2}}[/tex]
I'd like to know how to invert it for other values of alpha. My only recourse is to evaluate the complex contour for the inverse transform:
[tex]\frac{1}{2\pi i}\int_{\gamma-i\infty}^{\gamma+i\infty} Y(p)e^{pt}dp[/tex]
I'm not too good at this. I know I need to learn more about Complex Analysis and contours specifically, but for the time being, can someone help me through the integral for alpha=1/2:
[tex]\frac{1}{2\pi i}\int_{\gamma-i\infty}^{\gamma+i\infty} \frac{e^{st}}{e^{2\sqrt{\pi s}}}ds=\frac{e^{-\pi/t}}{t^{3/2}}[/tex]
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