Search results
Results from the WOW.Com Content Network
The lattice of subgroups of the infinite cyclic group can be described in the same way, as the dual of the divisibility lattice of all positive integers. If the infinite cyclic group is represented as the additive group on the integers, then the subgroup generated by d is a subgroup of the subgroup generated by e if and only if e is a divisor ...
A cyclic group is a group which is equal to one of its cyclic subgroups: G = g for some element g, called a generator of G. For a finite cyclic group G of order n we have G = {e, g, g 2, ... , g n−1}, where e is the identity element and g i = g j whenever i ≡ j (mod n); in particular g n = g 0 = e, and g −1 = g n−1.
The subgroups of any given group form a complete lattice under inclusion, called the lattice of subgroups. (While the infimum here is the usual set-theoretic intersection, the supremum of a set of subgroups is the subgroup generated by the set-theoretic union of the subgroups
In mathematics, the classification of finite simple groups (popularly called the enormous theorem [1] [2]) is a result of group theory stating that every finite simple group is either cyclic, or alternating, or belongs to a broad infinite class called the groups of Lie type, or else it is one of twenty-six exceptions, called sporadic (the Tits group is sometimes regarded as a sporadic group ...
The dihedral group Dih 4 has ten subgroups, counting itself and the trivial subgroup. Five of the eight group elements generate subgroups of order two, and the other two non-identity elements both generate the same cyclic subgroup of order four. In addition, there are two subgroups of the form Z 2 × Z 2, generated by pairs of order-two ...
For powers of 2 the factor (/) is not cyclic unless k = 0, 1, 2, but factors into cyclic groups as described above. The order of the group φ ( n ) {\displaystyle \varphi (n)} is the product of the orders of the cyclic groups in the direct product.
These Hasse diagrams show the lattices of subgroups of the symmetric group S 4, the dihedral group D 4, and C 2 3, the third direct power of the cyclic group C 2. The maximal subgroups are linked to the group itself (on top of the Hasse diagram) by an edge of the Hasse diagram.
Normal subgroups are important because they (and only they) can be used to construct quotient groups of the given group. Furthermore, the normal subgroups of G {\displaystyle G} are precisely the kernels of group homomorphisms with domain G {\displaystyle G} , which means that they can be used to internally classify those homomorphisms.