Hubbard, D., Washington, L., Iwasawa Invariants of some non-Cyclotomic Z_p-extensions, Journal of Number Theory, 2018

Iwasawa showed that there are non-cyclotomic extensions with positive μ-invariant. We show that these μ-invariants can be evaluated explicitly in many situations when p=2 and p=3.

Hubbard, D., Washington, L., Kummer generators and lambda-invariants, Journal of Number Theory, 2010

Let F_0 be an imaginary quadratic field and let K_0 be the corresponding real quadratic field as in Scholz’s Theorem. Let λ be the Iwasawa λ-invariant for the cyclotomic Z_3-extension of F_0. We construct units of K_1, the first level of the Z_3-extension of K, that potentially occur as Kummer generators of unramified extensions of F_1(ζ_3) and which give an algebraic interpretation of the condition that λ ≥ 2. We also discuss similar results on λ ≥ 2 that arise from work of Gross–Koblitz.

Hubbard, D., Dihedral side extensions and class groups, Journal of Number Theory, 2008

A more appropriate title would have been “A non-abelian mirror principal for class groups of dihedral number fields”

We present a non-abelian mirror-type principle relating the p-ranks of class groups of subfields of a dihedral field of degree 2p for an odd prime p with a limited ramification condition.