2024/05/04 by Clément de Seguins Pazzis, Pazzis, Clément de Seguins · 1 citation
Computer Science · Decision Sciences · Mathematics · #Advanced Topics in Algebra #FOS: Mathematics #Fuzzy and Soft Set Theory #Matrix Theory and Algorithms #Rings and Algebras (math.RA)
paper · pdf · doi:10.48550/arxiv.2405.02689
openalex publication_date 2024/05/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Let \mathbbF be a field, and n ≥ p ≥ r>0 be integers. In a recent article, Rubei has determined, when \mathbbF is the field of real numbers, the greatest possible dimension for an affine subspace of n--by--p matrices with entries in \mathbbF in which all the elements have rank r. In this note, we generalize her result to an arbitrary field with more than r+1 elements, and we classify the spaces that reach the maximal dimension as a function of the classification of the affine subspaces of invertible matrices of Ms(\mathbbF) with dimension \dbinoms2. The latter is known to be connected to the classification of nonisotropic quadratic forms over \mathbbF up to congruence.