It’s only recently, when reflecting on my PhD, that I realised my research niche wasn’t my topic.
It wasn’t skein invariants of knots, or two-variable polynomial properties of three-dimensional links; that was my topic, but my niche was edge cases and little results. During my PhD I looked for small problems; I searched for opportunities to apply methods to specific restricted cases. I proved a couple of open theorems, but I really loved finding processes for calculating things. My niche was algorithms, not knot theory. My niche was the questions I was asking, not the part of my field that I was exploring.
So what is your niche? How would you describe it? What does it mean to you? Do you have a neat way of telling others about it?
And do you have a useful way of describing it in the viva, if your examiners should ask?