Can the Axisymmetric Poisson Equation for Magnetostatics be Solved?

Wiemster
Messages
70
Reaction score
0
For a magnetostatics problem I seek the solution to the following equation

\frac{1}{x}\frac{d}{dx} \left( x \frac{dy(x)}{dx} \right) = -C^2 y(x)

(C a real constant) or equivalently

x \frac{d^2 y(x)}{dx^2} + \frac{dy(x)}{dx} + C^2 x y(x)=0

It seems so simple, but finding a particular solution beats me...is this solvable?
 
Last edited:
Physics news on Phys.org
If you rescale variables to get rid of the C^2 it looks like you could get it into the form of the differential equation for a zeroth order Bessel function. The general equation for a Bessel function is:

x^2 \frac{d^2 y}{dx^2} + x \frac{dy}{dx} + (x^2 - \alpha^2)y = 0

So with alpha = 0, you could divide out an x (or equivalently mutliply your equation by one) and it matches your equation - you just need to scale out the constant. i.e., somehow you want to scale that last term such that C^2xy \rightarrow xy with the other terms remaining unchanged.
 
That's great! Thank you very much...works like a charm!
 
There is the following linear Volterra equation of the second kind $$ y(x)+\int_{0}^{x} K(x-s) y(s)\,{\rm d}s = 1 $$ with kernel $$ K(x-s) = 1 - 4 \sum_{n=1}^{\infty} \dfrac{1}{\lambda_n^2} e^{-\beta \lambda_n^2 (x-s)} $$ where $y(0)=1$, $\beta>0$ and $\lambda_n$ is the $n$-th positive root of the equation $J_0(x)=0$ (here $n$ is a natural number that numbers these positive roots in the order of increasing their values), $J_0(x)$ is the Bessel function of the first kind of zero order. I...
Are there any good visualization tutorials, written or video, that show graphically how separation of variables works? I particularly have the time-independent Schrodinger Equation in mind. There are hundreds of demonstrations out there which essentially distill to copies of one another. However I am trying to visualize in my mind how this process looks graphically - for example plotting t on one axis and x on the other for f(x,t). I have seen other good visual representations of...
Back
Top