Comparative monotonicity of linear codes by Hermitian and symplectic hull dimensions
Combinatorics
2026-05-29 v1
Abstract
Extending recent work on the Euclidean hull, we derive closed-form ratio decompositions for the number of linear codes with prescribed Hermitian and symplectic hull dimension. The Hermitian ratio admits a uniform lower bound of at least , while the symplectic ratio decays to asymptotically; a comparative analysis traces this qualitative difference to the Witt classification of the corresponding classical groups. The results translate directly into monotonicity statements for the number of entanglement-assisted quantum codes obtainable from Hermitian-hull-graded and symplectic-hull-graded classical codes via the Guenda-Jitman-Gulliver and Wilde-Brun constructions, respectively.
Cite
@article{arxiv.2605.29204,
title = {Comparative monotonicity of linear codes by Hermitian and symplectic hull dimensions},
author = {Keita Ishizuka},
journal= {arXiv preprint arXiv:2605.29204},
year = {2026}
}