Is There a Rigorous Method to Regularize Green's Functions in Coordinate Space?

[Einj]

Hello everyone,
I would like to know if there is a known, rigorous way to regularize a Green's function in coordinate space. In particular, it is known that the Green's function for a circle of radius R and source located at \vec x_0 is given by:
$$
G(\vec x,\vec x_0)=\frac{1}{2\pi}\ln\left[\frac{\left|\vec x-\vec x_0\right|}{\left|\vec x-\frac{R^2}{|\vec x_0|^2}\vec x_0\right|}\frac{R}{|\vec x_0|} \right],
$$
and therefore for \vec x=\vec x_0 diverges as \frac{1}{2\pi}\ln\left|\vec x-\vec x_0\right|. Is there any rigorous way of regularizing this function? The most natural way that is coming to my mind is clearly to subtract the divergence by simply defining:
$$
G_R(\vec x,\vec x_0)=G(\vec x,\vec x_0)-\frac{1}{2\pi}\ln\left|\vec x-\vec x_0\right|.
$$

Am I right? Is this rigorous?

Thanks a lot!

 

[jasonRF]

What do you mean by "regularize" it, and why do you want to do it? We usually expect Green's functions to be singular at the source location.