On the Iwasawa invariants of Artin representations
Aditya Karnataki, Anwesh Ray
TL;DR
The paper investigates Iwasawa invariants $\mu_p$ and $\lambda_p$ attached to Selmer groups $S_{\chi,\epsilon}(\mathbb{Q}_\infty)$ of irreducible Artin representations. It develops an Euler-characteristic framework and control theorems (Greenberg–Vatsal) to obtain explicit vanishing criteria for these invariants, connecting them to $p$-rationality of the base field and to distribution questions for primes. Special cases in low-dimensional Artin representations (dihedral 2D and icosahedral 3D) illustrate concrete vanishing criteria, while distribution results tie the arithmetic of $p$-rational primes to the behavior of Selmer groups. The work further links classical Iwasawa theory of class groups with Selmer-theoretic phenomena for Artin representations, offering heuristic densities and unconditional results in certain $S_3$-extensions through conjectures like Gras and the Maire–Rougnant findings on $p$-rationality.
Abstract
We study Iwasawa invariants associated to Selmer groups of Artin representations, and criteria for the vanishing of the associated algebraic Iwasawa invariants. The conditions obtained can be used to study natural distribution questions in this context.
