The Hasse conjecture for cyclic extensions.
It is known that there are only finitely many imaginary abelian number fields with class numbers equal to their genus class numbers. Here, we determine all the imaginary cyclic sextic fields with class numbers equal to their genus class numbers.
We give exhaustive list of biquadratic fields and without -exotic symbol, i.e. for which the -rank of the Hilbert kernel (or wild kernel) is zero. Such are logarithmic principals [J3]. We detail an exemple of this technical numerical exploration and quote the family of theories and results we utilize. The -rank of tame, regular and wild kernel of -theory are connected with local and global problem of embedding in a -extension. Global class field theory can describe the -rank of the Hilbert...
We investigate as Galois module the unit group of biquadratic extensions of number fields. The -rank of the first cohomology group of units of is computed for general . For imaginary quadratic we determine a large portion of the cases (including all unramified ) where the index takes its maximum value , where are units mod torsion of and are units mod torsion of one of the 3 quadratic subfields of .
On étudie une famille de corps réels cycliques de degré 10 liés à la courbe modulaire . Les unités modulaires déterminent un sous-groupe d’unités d’indice fini. Sous certaines conditions, cet indice est égal à 1 ou 5.
Let be an algebraic unit of the degree . Assume that the extension is Galois. We would like to determine when the order of is -invariant, i.e. when the complex conjugates of are in , which amounts to asking that , i.e., that these two orders of have the same discriminant. This problem has been solved only for by using an explicit formula for the discriminant of the order . However, there is no known similar formula for . In the present paper, we put forward and motivate three...