He just gave the general domain of the project, it would be weird to start this kind of semi-retirement on a very specific domain. I see this as the broad topic

He just gave the general domain of the project, it would be weird to start this kind of semi-retirement on a very specific domain. I see this as the broad topic of interest that he will be investigating, but any actual research will be done into narrow fields, wherever some interesting idea hasn't been fully explored yet.