Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The multivariate Charlier polynomials as matrix elements of the
  Euclidean group representation on oscillator states   A family of multivariate orthogonal polynomials generalizing the standard
(univariate) Charlier polynomials is shown to arise in the matrix elements of
the unitary representation of the Euclidean group E(d) on oscillator states.
These polynomials in d discrete variables are orthogonal on the product of d
Poisson distributions. The accent is put on the d=2 case and the group
theoretical setting is used to obtain the main properties of the polynomials:
orthogonality and recurrence relations, difference equation, raising/lowering
relations, generating function, hypergeometric and integral representations and
explicit expression in terms of standard Charlier and Krawtchouk polynomials.
The approach is seen to extend straightforwardly to an arbitrary number of
variables. The contraction of SO(3) to E(2) is used to show that the bivariate
Charlier polynomials correspond to a limit of the bivariate Krawtchouk
polynomials.

22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an