Orthogonal graphs of characteristic 2 and their automorphisms
Autor: | Zhe-Xian Wan, Kai Zhou |
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Rok vydání: | 2009 |
Předmět: | |
Zdroj: | Science in China Series A: Mathematics. 52:361-380 |
ISSN: | 1862-2763 1006-9283 |
Popis: | The (singular) orthogonal graph O(2ν + δ, q) over a field with q elements and of characteristic 2 (where ν ⩾ 1, and δ = 0, 1 or 2) is introduced. When ν = 1, O(2 · 1, q), O(2 · 1 + 1, q) and O(2 · 1 + 2, q) are complete graphs with 2, q + 1 and q2 + 1 vertices, respectively. When ν ⩾ 2, O(2ν + δ, q) is strongly regular and its parameters are computed. O(2ν + 1, q) is isomorphic to the symplectic graph Sp(2ν, q). The chromatic number of O(2ν + ν, q) except when δ = 0 and ν is odd is computed and the group of graph automorphisms of O(2ν + δ, q) is determined. |
Databáze: | OpenAIRE |
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