Rank 5 association schemes and triality
Rank 5 association schemes and triality
复制标题
5级关联计划和试用
DOI:
10.1016/0024-3795(95)00102-w
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发表时间:
1995
影响因子:
1.1
通讯作者:
D. G. Higman
中科院分区:
文献类型:
--
作者:
D. G. Higman
Symmetric association schemes having a parabolic of rank 3 and corank 2 satisfying a certain uniformity condition can be interpreted on the one hand as linked strongly regular designs (analogous to linked symmetric designs) and on the other as geometries. Classical triality associated with the groups O+8(q) provides a family of examples with rank 3, corank 2 parabolics and sporadic examples are associated with the groups L3(4), U6(2) and U3(5). The triality examples and the U3(5) example are flag-transitive viewed as geometries. Results include a characterization on the level of parameters of the triality schemes leading to a characterization of the schemes using results of Cameron and Drake, and a proof (as a Cayley exercise) of simple connectivity of the example associated with U3(5).