A large number of posts in this part of the forum seem very similar, namely how broad or narrow fields of interest one ought to mention, and whether to name specific professors and so on. It also appears that answers vary greatly. I admit that this is somewhat related.
Here is my situation: I am an international student with an MSc in theoretical physics, currently taking a year out. In Europe, I would now be at the level of starting research for my PhD (if I got a place at some university). I have essentially two questions.
1. I understand that in general US students apply for a PhD position from being an undergraduate (or with a completed undergraduate degree) and upon acceptance do one or two years of taught graduate school rather than going straight into research. This, it seems to me, means that one would not have to be completely specific about one's field of research (as one would have a year or two before actually starting it and as an undergraduate one probably won't have had that much research-level courses anyway). Having done a graduate degree already though I could be extremely specific in my SOP about areas of research I am interested in. Should I be that specific, or should I acknowledge the possibility of discovering other fields I might be interested in during the taught part of the PhD?
It goes without saying, of course, that applying to the right schools for my field, with the right professors suitable for my interests, etc., is perhaps of even greater importance, but some advice or experiences regarding what kind of specialisation is expected would be helpful.
2. Somewhat related (although not exactly concerning the SOP but not wanting to create an extra post in a different section of the forum), given that I already have had graduate schooling, are there ways to skip/shorten the taught component of a PhD? I would imagine that it is in the school's interest to be accomodating for various levels of education, but looking at descriptions of PhD programs on various university websites, I have spotted no such flexibility.
Many thanks for your answers!