Lewis Combes

activity

20232026

collaborators

5 papers

math.NT2026

Lifting ethereal Bianchi modular forms

Lewis Combes, Håvard Damm-Johnsen

Mod $p$ Hecke eigenforms for congruence subgroups of $SL_{2} (Z)$ which do not lift to characteristic $0$ have received much attention, and were named ethereal…

math.NT2025

Computing Selmer groups associated to mod p Galois representations

Lewis Combes

We present methods to compute Selmer groups associated to mod p Galois representations rho over a number field K, with a particular focus on comparing their ranks with periods comi…

math.GR2024

Creating a dynamic database of finite groups

Lewis Combes, John W. Jones, Jennifer Paulhus +3

A database of abstract groups has been added to the L-functions and Modular Forms Database (LMFDB), available at https://www.lmfdb.org/Groups/Abstract/. We discuss the functionalit…

math.NT2024

Expressions for weight 2 cusp forms in holomorphic eta quotients

Elisabeth Chan, Lewis Combes

We attempt to compute expressions in terms of the Dedekind eta function for all weight 2 new cusp forms with level up to 100, using methods of Allen et. al. In cases where no expre…

math.NT2023

Bianchi period polynomials: Hecke action and congruences

Lewis Combes

Let $Γ$ be a Bianchi group associated to one of the five Euclidean imaginary quadratic fields. We show that the space of weight $k$ period polynomials for $Γ$ is ``dual'' to the sp…