Krein parameters of fiber-commutative coherent configurations
Combinatorics
2019-12-16 v4
Abstract
For fiber-commutative coherent configurations, we show that Krein parameters can be defined essentially uniquely. As a consequence, the general Krein condition reduces to positive semidefiniteness of finitely many matrices determined by the parameters of a coherent configuration. We mention its implications in the coherent configuration defined by a generalized quadrangle. We also simplify the absolute bound using the matrices of Krein parameters.
Keywords
Cite
@article{arxiv.1901.11484,
title = {Krein parameters of fiber-commutative coherent configurations},
author = {Keiji Ito and Akihiro Munemasa},
journal= {arXiv preprint arXiv:1901.11484},
year = {2019}
}
Comments
13 pages. Corrected typo. To appear in Algebra Colloquium