On the Hilbert 2-class field tower of some abelian 2-extensions over the field of rational numbers

Abstract

It is well known by results of Golod and Shafarevich that the Hilbert 2-class field tower of any real quadratic number field, in which the discriminant is not a sum of two squares and divisible by eight primes, is infinite. The aim of this article is to extend this result to any real abelian 2-extension over the field of rational numbers. So using genus theory, units of biquadratic number fields and norm residue symbol, we prove that for every real abelian 2-extension over ℚ in which eight primes ramify and one of theses primes ≡ −1 (mod 4), the Hilbert 2-class field tower is infinite.