I have recently asked a few questions about QFT in curved spacetime, and have noticed that there is no existing tag for this topic. I looked around the forum some more and found that there are several questions which would fall under this category, so I think it could be a useful addition.
However, when I tried to create a tag I was told that tags can not exceed 25 characters. This makes perfect sense, but then it becomes quite hard to create an appropriate tag. Therefore, I was wondering: What would be a good tag name for questions like these?