Diracs delta equation - general interpretation

finitefemmet
Messages
13
Reaction score
0
Im really just searching for a general explanation!

If you are solving a pretty standard left hand side differential equation, but a diracs delta function on the right hand side. I am abit confused about how to interpret this.

If this is the case for the right hand side:

r(t) = Diracs (t) ,for 0≤ t<T with the period T=2∏

Think of this as an periodic outside force on a spring system, now I don't know how to interpret this. Does this mean that r(t) repeats itself, at t=0, t=2∏ and so on. Or that the diracs delta equation only excists between 0 and 2∏?

Since its a diracs delta equation, it cannot work over a longer time interval? Since its an instant impuls over an extremely small time space.

If anyone could shed some light over this, I would be most gratefull.
I am not looking for a solution, just general information on how to interpret this information with the diracs delta function

Thank you:smile:, and excuse my poor english!
 
Last edited:
Physics news on Phys.org
They mean that the function repeats itself
 
For every positive integer k, let fk(t)=
0 for 2(n-1)pi+ 1/k to 2npi- 1/k,
k/2 for 2npi- 1/k to 2npi+ 1/k

for n any positive integer. The periodic "delta function" is the limit of fk(x) as k goes to infinity. Essentially, that gives a "delta function" at every multiple of 2pi.
 
Thank you both;)
 
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