Leveraging MO to organize mathematical research I am currently studying an existence lemma that appears to be simple yet powerful. From what I know about it, it is applicable in combinatorics, topology, graph theory, probability, percolation theory, game theory, maybe other fields as well (here is a graph theory version Graph with path of length $\geq n$ along grid diagonals - a known result in graph theory?). Informally, it seems to me as versatile and powerful as the Lemma of Sperner, and feel it has a role to play in various fields. To explore its strength, I would like to connect with a few users on MO, from different fields, who were touching on it in their posts. I would like to ask them if they could be interested to collaborate in the study of this lemma across fields. How can I do that? Should I ask it as a question on MO, or is there another way of connecting? For example, is there a way to invite them to a chat?

If you are too forward in your approach, you risk alienating those you wish to solicit. I recommend the MathOverflow user page to state the invitation in full (or concisely with a link to a longer invitation), and then ever so occasionally and with maximum level of relevance and propriety link to it in a comment to another user. If they don't have interest at the time to follow the link, they (or some other reader) may develop that interest later. However, many come to this forum because this is precisely the level of interaction they desire. Be very careful in how you ask for more.

Gerhard "Buy Them A Drink First?" Paseman, 2020.05.21.