Search results
Results from the WOW.Com Content Network
The unitary group is a subgroup of the general linear group GL(n, C), and it has as a subgroup the special unitary group, consisting of those unitary matrices with determinant 1. In the simple case n = 1, the group U(1) corresponds to the circle group, isomorphic to the set of all complex numbers that have absolute value 1, under multiplication ...
For that group all permutations of the three non-identity elements are automorphisms, so the automorphism group is isomorphic to (which itself is isomorphic to ). In Z p {\displaystyle \mathbb {Z} _{p}} for a prime number p , {\displaystyle p,} one non-identity element can be replaced by any other, with corresponding changes in the other elements.
That is, an element u of a ring R is a unit if there exists v in R such that = =, where 1 is the multiplicative identity; the element v is unique for this property and is called the multiplicative inverse of u. [1] [2] The set of units of R forms a group R × under multiplication, called the group of units or unit group of R.
The group I is isomorphic to A 5, the alternating group on 5 letters, since its elements correspond 1-to-1 with even permutations of the five T symmetries (or the five tetrahedra just mentioned). Representing rotations with quaternions, I is made up of the 120 unit icosians. As before, this is a 1-to-2 correspondence. I h, (*532) [5,3] 5 3 2/m ...
Another characterization is that a finite p-group in which there is a unique subgroup of order p is either cyclic or a 2-group isomorphic to generalized quaternion group. [13] In particular, for a finite field F with odd characteristic, the 2-Sylow subgroup of SL 2 ( F ) is non-abelian and has only one subgroup of order 2, so this 2-Sylow ...
The set of all nonzero scalar matrices forms a subgroup of GL(n, F) isomorphic to F ×. This group is the center of GL(n, F). In particular, it is a normal, abelian subgroup. The center of SL(n, F) is simply the set of all scalar matrices with unit determinant, and is isomorphic to the group of nth roots of unity in the field F.
Note that if K is Galois over then either r 1 = 0 or r 2 = 0.. Other ways of determining r 1 and r 2 are . use the primitive element theorem to write = (), and then r 1 is the number of conjugates of α that are real, 2r 2 the number that are complex; in other words, if f is the minimal polynomial of α over , then r 1 is the number of real roots and 2r 2 is the number of non-real complex ...
Every group G can be viewed as a category with a single object; morphisms in this category are just the elements of G. Given an arbitrary category C, a representation of G in C is a functor from G to C. Such a functor selects an object X in C and a group homomorphism from G to Aut(X), the automorphism group of X.