In
mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...
, a sequence of discrete
orthogonal polynomials is a sequence of polynomials that are pairwise orthogonal with respect to a discrete measure.
Examples include the
discrete Chebyshev polynomials,
Charlier polynomials In mathematics, Charlier polynomials (also called Poisson–Charlier polynomials) are a family of orthogonal polynomials introduced by Carl Charlier.
They are given in terms of the generalized hypergeometric function by
:C_n(x; \mu)= _2F_0(-n,-x;-;- ...
,
Krawtchouk polynomials,
Meixner polynomials,
dual Hahn polynomials,
Hahn polynomials, and
Racah polynomials.
If the measure has finite support, then the corresponding sequence of discrete orthogonal polynomials has only a finite number of elements. The
Racah polynomials give an example of this.
Definition
Consider a
discrete measure on some set
with weight function
.
A family of orthogonal polynomials
is called discrete, if they are orthogonal with respect to
(resp.
), i.e.
:
where
is the
Kronecker delta.
Remark
Any discrete measure is of the form
:
,
so one can define a weight function by
.
Listeratur
*{{Citation , last1=Baik , first1=Jinho , last2=Kriecherbauer , first2=T. , last3=McLaughlin , first3=K. T.-R. , last4=Miller , first4=P. D. , title=Discrete orthogonal polynomials. Asymptotics and applications , url=https://books.google.com/books?id=S-GIGgx05kgC , publisher=
Princeton University Press , series=Annals of Mathematics Studies , isbn=978-0-691-12734-7 , mr=2283089 , year=2007 , volume=164
References
Orthogonal polynomials