GEOMETRIC CHARACTERIZATION OF THE SPORADIC GROUPS FI(22), FI(23), AND FI(24)

[摘要] Let SIGMA1,..., SIGMA4 be the 3-transposition graphs for Fischer's sporadic groups Fi21,..., Fi24. We classify connected locally SIGMA(i) graphs THETA = THETA(i+1) for i = 1,2,3. In the minimal case i = 1 we also assume that for every nondegenerate 4-circuit abcd the subgraph THETA(a, b, c, d) is isomorphic to the disjoint union of three copies of K3,3. If i = 1, 2 then THETA is isomorphic to SIGMA(i+1), whereas if i = 3 then THETA is isomorphic either to SIGMA4 or to its 3-fold antipodal cover 3SIGMA4. (C) 1994 Academic Press, Inc.

[发布日期] 1994-10-01