Search results
Results from the WOW.Com Content Network
The space of complex-valued class functions of a finite group G has a natural inner product: , := | | () ¯ where () ¯ denotes the complex conjugate of the value of on g.With respect to this inner product, the irreducible characters form an orthonormal basis for the space of class functions, and this yields the orthogonality relation for the rows of the character table:
In mathematics, Schur's lemma [1] is an elementary but extremely useful statement in representation theory of groups and algebras.In the group case it says that if M and N are two finite-dimensional irreducible representations of a group G and φ is a linear map from M to N that commutes with the action of the group, then either φ is invertible, or φ = 0.
In mathematics, orthogonal functions belong to a function space that is a vector space equipped with a bilinear form.When the function space has an interval as the domain, the bilinear form may be the integral of the product of functions over the interval:
The orthogonality relations can aid many computations including: Decomposing an unknown character as a linear combination of irreducible characters. Constructing the complete character table when only some of the irreducible characters are known. Finding the orders of the centralizers of representatives of the conjugacy classes of a group.
In analytic number theory and related branches of mathematics, a complex-valued arithmetic function: is a Dirichlet character of modulus (where is a positive integer) if for all integers and : [1]
Like the sines and cosines in Fourier series, the spherical harmonics may be organized by (spatial) angular frequency, as seen in the rows of functions in the illustration on the right. Further, spherical harmonics are basis functions for irreducible representations of SO(3) , the group of rotations in three dimensions, and thus play a central ...
The Fourier series is a method of expressing a periodic function in terms of sinusoidal basis functions. Taking C[−π,π] to be the space of all real-valued functions continuous on the interval [−π,π] and taking the inner product to be , = ()
Orthogonality relations [ edit ] A system of two angular momenta with magnitudes j 1 and j 2 can be described either in terms of the uncoupled basis states (labeled by the quantum numbers m 1 and m 2 ), or the coupled basis states (labeled by j 3 and m 3 ).