A Simple Subgroup of M? and E8(3)
A Simple Subgroup of M? and E8(3)
复制标题
M 的简单子群?
DOI:
10.1112/blms/8.2.161
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发表时间:
1976
影响因子:
0.9
通讯作者:
P. E. Smith
中科院分区:
文献类型:
--
作者:
P. E. Smith
The purpose of this note is to announce the construction in May 1974 of a new simple group E of order 90, 745, 943, 887, 872, 000= 215. 310. 53. 72. 13.19. 31 at Cambridge by JG Thompson and the present author. This is the result of certain investigations by JG Thompson into the hypothetical monster group M? of B. Fischer; it is conjectured that the centralizer in M? of a suitable element of order 3 is C3 x E. Let me say at the outset that my involvement in this work has been the computer construction; the mathematics is Thompson's work. The ceritralizer of an involution a of E is 21+ 8 A9, ie C= C£(a) contains a normal extra-special subgroup H of order 29 such that C/H£ A9\it is in terms of this property that Thompson constructs E. It will be seen from the appended character table of E (chiefly the work of Thompson and JH Conway) that the least degree of a faithful ordinary representation is 248; let this afford the character X. Various arguments may be employed to show that this may be assumed to be an integer representation; that is, there exists a 248-dimensional lattice L* stabilized by E. The irreducibility of this representation modulo all primes shows that L* may be scaled to be unimodular. We shall construct a group E* of transformations of 248-space; it will be shown by computer that E^ E*. If p eH is any non-central involution, set F= O2 (CE (aj) n O2 (C£(jS)), D= iVE (F). F is elementary abelian of order 25, D/F SL 2 (5) and D does not split over F. U. Dempwolffhas shown, in [2], that if such an extension exists it is unique. Accordingly we term D (which we construct explicitly) the Dempwolff Group. Every faithful representation of D over the complex field has degree^ 248, there being a unique faithful representation (j) of degree 248, to which the 248-representation of E must restrict. Thompson has constructed a decomposition of the complex Lie-algebra