Order complex;
Coset poset;
Finite group;
Smith Theory;
PROBABILISTIC ZETA-FUNCTION;
PRIMITIVE PERMUTATION-GROUPS;
EULER CHARACTERISTICS;
(NON-)CONTRACTIBILITY;
SUBGROUPS;
D O I:
10.1016/j.aim.2015.10.018
中图分类号:
O1 [数学];
学科分类号:
0701 ;
070101 ;
摘要:
We show that the order complex of the poset of all cosets of all proper subgroups of a finite group G is never F-2-acyclic and therefore never contractible. This settles a question of K.S. Brown. (C) 2015 Published by Elsevier Inc.