Wigner Semicircle Distribution - General Properties

General Properties

The Chebyshev polynomials of the second kind are orthogonal polynomials with respect to the Wigner semicircle distribution.

For positive integers n, the 2n-th moment of this distribution is

where X is any random variable with this distribution and Cn is the nth Catalan number

so that the moments are the Catalan numbers if R = 2. (Because of symmetry, all of the odd-order moments are zero.)

Making the substitution into the defining equation for the moment generating function it can be seen that:

which can be solved (see Abramowitz and Stegun §9.6.18) to yield:

where is the modified Bessel function. Similarly, the characteristic function is given by:

where is the Bessel function. (See Abramowitz and Stegun §9.1.20), noting that the corresponding integral involving is zero.)

In the limit of approaching zero, the Wigner semicircle distribution becomes a Dirac delta function.

Read more about this topic:  Wigner Semicircle Distribution

Famous quotes containing the words general and/or properties:

    Towards him they bend
    With awful reverence prone; and as a God
    Extoll him equal to the highest in Heav’n:
    Nor fail’d they to express how much they prais’d,
    That for the general safety he despis’d
    His own: for neither do the Spirits damn’d
    Loose all thir vertue; lest bad men should boast
    Thir specious deeds on earth, which glory excites,
    Or close ambition varnisht o’er with zeal.
    John Milton (1608–1674)

    A drop of water has the properties of the sea, but cannot exhibit a storm. There is beauty of a concert, as well as of a flute; strength of a host, as well as of a hero.
    Ralph Waldo Emerson (1803–1882)