He proved there is a natural isomorphism:where k is a perfect field of characteristic p, W(k) is the Witt ring of k, K is the fractional field of W(k), K|- is a fixed algebraic closure of K, K~(cyc) is the exension of K by joining all roots of unity.
英
美
- 是K的一個(gè)固定的代數閉包,K~(cyc)是K添加所有的單位根。 在我們的研究中,特征0的問(wèn)題與特征p的問(wèn)題經(jīng)常是相互轉化的,如在第一部分,我們必須將特征p的域提升至特征0;