Can a research statement contain research interests which are not concrete? I am applying for postdoc in physics this year. Every place asks for a statement of research or research plan/proposal for the application procedure. I have been recently following papers on a very interesting topic of research. Although I have no concrete problem/question in mind. I cannot resist myself from mentioning this topic of interest. I was wondering if I can write something like the following in a statement of research :  

"I am also very interested in X. I have been closely following the rapid progress in this direction and hope to contribute in recent future."  

(I want this part to write at the end of my statement of research but these sentences don't sound nice to me at all!)
If a statement does not sound right to you, it is highly likely not to sound right to other people. So you might have as well just leave it out of your statement.

Focus on what you know and what you know you are in a position to focus on as part of your further research.

If you are selected, you will have plenty of opportunities to nurture your thoughts and ideas with stimulating colleagues.