On the Units of Algebraic Number Fields Original Research Article

Let K be an algebraic number field and k be a proper subfield of K. Then we have the relations between the relative degree [K : k] and the increase of the rank of the unit groups. Especially, in the case of mth cyclotomic field Q(ζm), we determine the number m such that the increase of the rank of the unit groups is equal to the number of the imaginary conjugates of the proper subfield.