后来在剑桥大学学宇宙学 翻译成英语 要限定性定语从句

.,after which he majored in cosmology in Cambridge University这是定于从句的后半句,前面应该还有个主句吧 要么就是 later,he went to Cambridge University where he majored in cosmology

Later, he went to Cambridge University where he studied cosmology