Invariant differentials and -functions. Reciprocity law for quadratic fields and elliptic curves over
Let be a prime number, and let be an imaginary quadratic number field in which decomposes into two primes and . Let be the unique -extension of which is unramified outside of , and let be a finite extension of , abelian over . Let be the projective limit of principal semi-local units modulo elliptic units. We prove that the various modules of invariants and coinvariants of are finite. Our approach uses distributions and the -adic -function, as defined in [5].
L’homomorphisme de classes mesure la structure galoisienne de torseurs – sous un schéma en groupes fini et plat – obtenus grâce au cobord d’une suite exacte. Son introduction est due à Martin Taylor (la suite exacte étant une isogénie entre schémas abéliens). Nous commençons par énoncer quelques propriétés générales de cet homomorphisme, puis nous poursuivons son étude dans le cas où la suite exacte est donnée par la multiplication par sur une extension d’un schéma abélien par un tore.
We build on preceeding work of Serre, Esnault-Kahn-Viehweg and Kahn to establish a relation between invariants, in modulo 2 étale cohomology, attached to a tamely ramified covering of schemes with odd ramification indices. The first type of invariant is constructed using a natural quadratic form obtained from the covering. In the case of an extension of Dedekind domains, mains, this form is the square root of the inverse different equipped with the trace form. In the case of a covering of Riemann...