Hello there, I'm a Undergraduate student of Physics from India. Recently I came across information regarding joining PhD programmes directly after completing undergraduate courses in Tata Institute of Fundamental Research. Frankly speaking, I didn't know it was possible. Now, since I solemnly want to continue my post undergraduate studies in USA, are there any similar opportunities there? As far as I know, I need to go through GRE to get admitted to US universities at graduate level, does that test also make me eligible to get enrolled into a direct PhD programme, if there any?