Supersingular Drinfeld modules, Brandt matrices, and rank-metric codes

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Micheli, Giacomo, Papikian, Mihran
Natura: Preprint
Pubblicazione: 2026
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866914486673211392
author Micheli, Giacomo
Papikian, Mihran
author_facet Micheli, Giacomo
Papikian, Mihran
contents We prove a stabilization result for the $\mathbb{F}_q$-dimension of spaces of morphisms between supersingular Drinfeld modules, filtered by degree: for any two supersingular rank-$2$ Drinfeld $\mathbb{F}_q[T]$-modules in characteristic $\frak{p}$ of degree $d$, the dimension $m_s$ of the space of morphisms of $τ$-degree at most $s$ satisfies $m_s = 2(s+1)-(d-1)$ for all $s\geq d-2$. This is proved using the theory of Brandt matrices and properties of $L$-functions of automorphic forms for $\mathrm{GL}_2$ over function fields. The stabilization formula, combined with an analysis of zero entries in Brandt matrices and a hyperplane-avoidance argument, yields semifield rank-metric codes. We also describe an efficient algorithm for computing the relevant Brandt matrices.
format Preprint
id arxiv_https___arxiv_org_abs_2604_17080
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Supersingular Drinfeld modules, Brandt matrices, and rank-metric codes
Micheli, Giacomo
Papikian, Mihran
Number Theory
11G09, 94B60, 11F41, 11R52, 16S36
We prove a stabilization result for the $\mathbb{F}_q$-dimension of spaces of morphisms between supersingular Drinfeld modules, filtered by degree: for any two supersingular rank-$2$ Drinfeld $\mathbb{F}_q[T]$-modules in characteristic $\frak{p}$ of degree $d$, the dimension $m_s$ of the space of morphisms of $τ$-degree at most $s$ satisfies $m_s = 2(s+1)-(d-1)$ for all $s\geq d-2$. This is proved using the theory of Brandt matrices and properties of $L$-functions of automorphic forms for $\mathrm{GL}_2$ over function fields. The stabilization formula, combined with an analysis of zero entries in Brandt matrices and a hyperplane-avoidance argument, yields semifield rank-metric codes. We also describe an efficient algorithm for computing the relevant Brandt matrices.
title Supersingular Drinfeld modules, Brandt matrices, and rank-metric codes
topic Number Theory
11G09, 94B60, 11F41, 11R52, 16S36
url https://arxiv.org/abs/2604.17080