2022/08/10 by Damián Pinasco, Pinasco, Damian
Computer Science · Mathematics · #52A40 #Advanced Differential Equations and Dynamical Systems #FOS: Mathematics #Functional Analysis (math.FA) #Mathematical Inequalities and Applications #Matrix Theory and Algorithms #Primary 46G25 #Secondary 26D05
paper · pdf · doi:10.48550/arxiv.2208.05584
openalex publication_date 2022/08/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We prove that given any set of n unit vectors \vi\i=1n⊂ \mathbb Rn, the inequality sup_\Vert x \Vert\mathbb Rn =1 \vert ⟨ x, v1 ⟩ ⋯ ⟨ x, vn⟩\vert ≥ n-n/2 holds for n ≤ 14. Moreover, the equality is attained if and only if \vi\i=1n is an orthonormal system.