Polynomial sequence
In mathematics, the Angelescu polynomials πn(x) are a series of polynomials generalizing the Laguerre polynomials introduced by Aurel Angelescu. The polynomials can be given by the generating function
They can also be defined by the equation
where
is an Appell set of polynomials[which?].
Properties
Addition and recurrence relations
The Angelescu polynomials satisfy the following addition theorem:
where
is a generalized Laguerre polynomial.
A particularly notable special case of this is when
, in which case the formula simplifies to
[clarification needed]
The polynomials also satisfy the recurrence relation
[verification needed]
which simplifies when
to
. This can be generalized to the following:
[verification needed]
a special case of which is the formula
.
Integrals
The Angelescu polynomials satisfy the following integral formulae:
(Here,
is a Laguerre polynomial.)
Further generalization
We can define a q-analog of the Angelescu polynomials as
, where
and
are the q-exponential functions
and
[verification needed],
is the q-derivative, and
is a "q-Appell set" (satisfying the property
).
This q-analog can also be given as a generating function as well:
where we employ the notation
and
.[verification needed]
References
- Angelescu, A. (1938), "Sur certains polynomes généralisant les polynomes de Laguerre.", C. R. Acad. Sci. Roumanie (in French), 2: 199–201, JFM 64.0328.01
- Boas, Ralph P.; Buck, R. Creighton (1958), Polynomial expansions of analytic functions, Ergebnisse der Mathematik und ihrer Grenzgebiete. Neue Folge., vol. 19, Berlin, New York: Springer-Verlag, ISBN 9783540031239, MR 0094466
- Shukla, D. P. (1981). "q-Angelescu polynomials" (PDF). Publications de l'Institut Mathématique. 43: 205–213.
- Shastri, N. A. (1940). "On Angelescu's polynomial πn (x)". Proceedings of the Indian Academy of Sciences, Section A. 11 (4): 312–317. doi:10.1007/BF03051347. S2CID 125446896.