The Flag-transitive Tilde and Petersen-type Geometries Are All Known
نویسندگان
چکیده
We announce the classification of two related classes of flag-transitive geometries. There is an infinite family of such geometries, related to the nonsplit extensions 3 n 2 ] 2 ·Sp2n(2), and twelve sporadic examples coming from the simple groups M22, M23, M24, He, Co1, Co2, J4, BM , M and the nonsplit extensions 3 · M22, 323 · Co2, and 34371 · BM .
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