Henri Johnston

activity

20052026

most citedNoncommutative Fitting invariants and improved annihilation results

30 citations · 70 across the 18 of their papers we have counts for

collaborators

22 papers

math.NT2026

Algorithms for $p$ -rationality and for $p$ -saturation of units

Tommy Hofmann, Henri Johnston

Let $K$ be a number field. We give new practical algorithms that determine whether $K$ is $p$ -rational. For real cyclotomic fields $K = Q (ζ_{n})^{+}$ , our method avoids comp…

math.NT2024

Determination of the stably free cancellation property for orders

Werner Bley, Tommy Hofmann, Henri Johnston

Let $K$ be a number field, let $A$ be a finite-dimensional semisimple $K$ -algebra, and let $Λ$ be an $O_{K}$ -order in $A$ . We give practical algorithms that determine whe…

math.NT2023★ 1 cited

On the existence of free sublattices of bounded index and arithmetic applications

Henri Johnston, Alex Torzewski

Let $O$ be a Dedekind domain whose field of fractions $K$ is a global field. Let $A$ be a finite-dimensional separable $K$ -algebra and let $Λ$ be an $O$ -order i…

math.NT2023

Applications of representation theory and of explicit units to Leopoldt's conjecture

Fabio Ferri, Henri Johnston

Let $L / K$ be a Galois extension of number fields and let $G = Gal (L / K)$ . We show that under certain hypotheses on $G$ , for a fixed prime number $p$ , Leopoldt's conjecture at…

math.NT2022

Computation of lattice isomorphisms and the integral matrix similarity problem

Werner Bley, Tommy Hofmann, Henri Johnston

Let $K$ be a number field, let $A$ be a finite-dimensional $K$ -algebra, let $J (A)$ denote the Jacobson radical of $A$ , and let $Λ$ be an $O_{K}$ -order in $A$ . Su…

math.NT2020★ 3 cited

An unconditional proof of the abelian equivariant Iwasawa main conjecture and applications

Henri Johnston, Andreas Nickel

Let $p$ be an odd prime. We give an unconditional proof of the equivariant Iwasawa main conjecture for totally real fields for every admissible one-dimensional $p$ -adic Lie extensi…