## What is L and M in spherical harmonics?

The indices ℓ and m indicate degree and order of the function. The spherical harmonic functions can be used to describe a function of θ and φ in the form of a linear expansion. Completeness implies that this expansion converges to an exact result for sufficient terms.

## What are spherical harmonic functions?

Spherical harmonics are a set of functions used to represent functions on the surface of the sphere S 2 S^2 S2. They are a higher-dimensional analogy of Fourier series, which form a complete basis for the set of periodic functions of a single variable (functions on the circle. S^1).

Are spherical harmonics eigenfunctions?

Spherical harmonics are defined as the eigenfunctions of the angular part of the Laplacian in three dimensions. As a result, they are extremely convenient in representing solutions to partial differential equations in which the Laplacian appears.

### Does L 2 commute with LZ?

z ,Lz]=0, so [L2,Lz]=0. Since there is nothing special about the z-axis, we conclude that L2 also commutes with Lx and Ly.

### How do you calculate eigenstate?

Thus, if Aψa(x)=aψa(x), where a is a complex number, then ψa is called an eigenstate of A corresponding to the eigenvalue a. so the variance of A is [cf., Equation ([e3. 24a])] σ2A=⟨A2⟩−⟨A⟩2=a2−a2=0.

What are the spherical harmonics?

The spherical harmonics are constructed to be the eigenfunctions of the angular part of the Laplacian in three dimensions, also called the Laplacian on the sphere. This construction is analogous to the case of the usual trigonometric functions

#### What is the addition formula for the spherical harmonics?

The addition formula forthe spherical harmonics Suppose we have two vectors ~r= (r,θ,φ), ~r′ = (r′,θ′,φ′), which are designated by their spherical coordinates, as shown in Figure 1 below. The angle between these two vectors, denoted by γ, is easily computed.

#### How do you find the parity of a spherical harmonics?

(This can be seen as follows: The associated Legendre polynomials gives (−1)ℓ+m and from the exponential function we have (−1)m, giving together for the spherical harmonics a parity of (−1)ℓ .)

Is the left-hand side of a spherical harmonic constant multiple of zonal harmonics?

In the expansion ( 1 ), the left-hand side Pℓ(x⋅y) is a constant multiple of the degree ℓ zonal spherical harmonic. From this perspective, one has the following generalization to higher dimensions. Let Yj be an arbitrary orthonormal basis of the space Hℓ of degree ℓ spherical harmonics on the n -sphere. Then