Scores for international student applying for PhD

[matilda9]

Hi,

I'm an international student (English is not my first language), taking the GRE in a week (for fall 2011) and I want to apply for PhD programs in business schools (at Harvard, NYU, MIT, Northwestern, and Columbia).

I still haven't started the applications formally, so I want to know what are the norms (for international student) in business departments and what are the unofficial minimum requirements. I asked a few department, but they either said they don't know or said they don't give that information. Is there anybody here who knows that, or knows how to find out?

(I want to know that in order to decide weather to apply this year to those schools, or to improve my grades and apply next year without spending a lot of money on applications that hardly stand a chance)

Thanks!