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arXiv · 1703.02943

Enumeration of Seidel matrices

Ferenc Szöllősi·Patric R. J. Östergård
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Abstract

In this paper Seidel matrices are studied, and their spectrum and several related algebraic properties are determined for order $n\leq 13$. Based on this Seidel matrices with exactly three distinct eigenvalues of order $n\leq 23$ are classified. One consequence of the computational results is that the maximum number of equiangular lines in $\mathbb{R}^{12}$ with common angle $1/5$ is exactly $20$.

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Ferenc Szöllősi, Patric R. J. Östergård. 2017-03-08. Enumeration of Seidel matrices. https://arxiv.org/abs/1703.02943

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