After quite some time in academia I ended up in a nice company but the math to use is not really demanding. Hence I am still reading and working a bit on some university level math. It's roughly at a bit advanced undergraduate or graduate math level depending on how close it is to the stuff I worked on.
That's fine so far, but I am missing the discussion about it. I remember well that it was a lot of fun to talk about a subject and it helped immensely to improve ones understanding. Hence I am looking for people interested in joint learning some specific subject, e.g. stochastic analysis, algebra, harmonic analysis to name just a few possibilities. Of course this would be only on a sort of educated amateur level as I could do it only in my spare time.
My question is now: Are there any online-platforms where one can find people who are willing to learn and work together on some math?
I am aware of xMOOCs and read some contributions posted here on math.stackexchange. I know such platforms like academia.edu or researchgate, too. But in contrast to the massive open online courses I am interested rather in small group online learning (SGOL, if you like). And the social networks for scientists like researchgate are, as the names say, for scientists and research. Well, I'ld love to do that again but... Needless to say, that I searched the web for some time with no success so far.
Thanks a lot for any hint!