Hi, I am from a maths/physics background currently doing a PhD in fluid mechanics within the engineering department. I am not enjoying it as much as I'd liked and have raised this with my supervisor (only just, I am not sure what the outcome will be yet), and having done a little research into possible connected directions I can take it, I feel as though one of them would involve co-supervising with someone in the mathematic department, and one, if possible, by someone who is at a different university- but was at my university for around ten years, leaving around five years ago, and seems to be the only person who has worked in this area (it seems pretty niche worldwide relative to other areas) with connections to my university. Is the latter heard of for co-supervision or is it a very long-shot? many thanks in advance

I would say it is fairly common in the UK. The university should have no issue with it but you could probably check with you graduate department about the technicalities, but I think it would be fairly easy. However, do you know if this mathematics lecturer would want to supervise you? You don't have to limit yourself to people who previously worked at your university but it could anyone that gets along with your main supervisor.

hey thanks alot for your reply, that's helpful :) re. on the last sentence yes ofc I thought so. On the previous sentence- this is another thing I am considering- who do I approach first here? my own supervisor having identified someone I would want to work with, or the potential co-supervisor first. the former seems silly if the potential co-supervisor would not be willing to work with us, and the latter seems rude, as though I should check with my own supervisor first. Many thanks :)