На странице университета Базеля читаем:

Foreign Doctoral students from countries other then the EU usually need a (student) VISA to be allowed to study in Switzerland.
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На странице университета EPFL в Лозанне читаем:

Students coming from a country NOT member of the ALCP (Free Movement of Persons Agreement) cannot enter Switzerland without a visa. You will need a valid passport and a visa issued by a Swiss embassy/consulate from your home country. Your home country will most surely issue you a visa valid for 1 or 2 months. Once you arrive in Switzerland, you will have to declare your arrival and apply for the residence/work permit.
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Real stupidity beats artificial intelligence every time. (Terry Pratchett)