As if to make this week any worse, my doppleganger is potentially conducting research that I am also doing - so I've recently discovered. The similarities are too much. We are both working on this one very specific system, so it cannot be overlooked. Fortunately, only two people in the nation or world are experts on this system, and one of the experts is myself.
When I approached my doppleganger, I first tried to be friendly and extend advice. I wrote that we should meet as a group to discuss the system because his student was asking around my lab and needed advice. The response from the doppleganger was simply that he would instruct his students not to speak with mine. There is a longer email thread, but he essentially comes out looking like a jerk.
What to do? I approached my official mentor, and then my chair. The emails were forwarded. I noted that another faculty member from Other University had warned me about the doppleganger in 2008. I noted that the doppleganger was present at my closed-door research proposal session when I interviewed at Other University, so he had full access to my research plan. My chair and mentor are going to meet to talk about it, and we'll see about this outcome. Its just a cherry on top of an already frustrating workplace.