The 6-step Solvable Mono-anabelian Reconstruction of Abelian Number Fields
Yu Mao
TL;DR
The paper addresses reconstructing abelian number fields from their maximal $6$-step solvable Galois groups $G_K^{6}$ and presents a self-contained, mono-anabelian reconstruction method that does not rely on prior Saïdi–Tamagawa results. It develops a local-to-global framework using NF-type and $ ext{GSC}^{6}$-type groups, proving that local decomposition data and cyclotomic information can be recovered from high-level solvable quotients, then assembles these into a global field $F(G)$ isomorphic to $K$ via a detailed chain of objects: $k(D)$, $F_n(D)$, $F_{ abla}(G)$, and the cyclotomic character to form $H_{ ext{cycl}}$ and $F(G)$. The main contribution is a concrete method to reconstruct abelian number fields from $G_K^{6}$, offering a new mono-anabelian pathway that is independent of previous bi-anabelian results. This advances the understanding of how solvable Galois quotients encode full field data and provides a practical blueprint for recovering $K$ from solvable Galois information.
Abstract
In this paper, we develop a new method to reconstruct an abelian number field $K$ from the maximal $6$-step solvable quotient of $G_K$ group- theoretically. The new aspect of this paper is that the results in this paper are independent from the bi-anabelian results proved proven by Saidi and Tamagawa in [ST22].
