I want to pursue for a Ph.D in these area.
There isn't any "best school"; there are best schools in various subfields. The best way to choose a grad school is to read the literature and find out which researchers are doing the most interesting work to you, talk to them about it ahead of time, and if they're taking students, go wherever they are.
Re: Re: Could someone tell me what is the best school in cosmology and high energy?
But I'm not in US, It's hard for me to contact with any of the
Just e-mail them; you can do that inside or outside of the country in question. That's what most prospective grad students do nowadays. (Of course, it's also nice to be able to talk to them in person, but it's not necessary.)
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