Dear friends, I have several problems regarding selection of major field and subfields. I greatly appreciate your help by answering the following questions. (I have done Physics, Chemistry and Com. Science and specialized subject is Physics. I did my final year research in material science - Advanced ceramics). 1. What are the most popular/competitive fields and least popular fields ( for Astronomy/physics) in US universities for PhD (chances of getting selected)? 2. Astronomy/astrophysics is my dream, but no astronomy/astrophysics courses was offered in my college undergraduate level (I was able to do only special relativity - 300 level and got A+). Will there be still a chance to get selected to do astronomy/astrophysics in USA? 3. I got good grades (A's or A+'s) for nuclear and particle physics areas but lack of research knowledge (as I'm from a developing country) might be a problem. If I get selected to nuclear, particle or high energy physics , is there a chance to do astrophysics in PhD.? These are the universities that I'm going to apply. Would you mind, please provide the most popular/competitive fields for each university (this will be a great help). Georgia state university Iowa state university University of Kansas Kansas State University Univ Of Massachusetts At Amherst University of Mississippi Ohio State University University of Houston Wayne State University Colorado State University University of Missouri Columbia Vanderbilt University Brown University Thank you very much. I hope to hear from you soon.