The q-deformed Poisson distribution has been introduced as the orthogonalizing probability measure for a certain q-deformation of Charlier polynomials, which is reduced to the usual Poisson distribution in the limit q→1 and takes the free Poisson distribution in case of q=0. We give the operator on the q-Fock space, which has the q-deformed Poisson distribution with respect to the vacuum state. It is a linear combination of a q-number operator, a q-Gaussian random variable, and a scalar operator. This representation is of the same form as of Hudson and Parthasarathy on the symmetric Fock space.
Let να,q be the probability and orthogonality measure for the q-Meixner-Pollaczek orthogonal polynomials, which has appeared in the work of Bożejko, Ejsmont, and Hasebe [J. Funct. Anal. 269, 1769–1795 (2015)] as the distribution of the (α, q)-Gaussian process (the Gaussian process of type B) over the (α, q)-Fock space (the Fock space of type B). The main purpose of this paper is to find the radial Bargmann representation of να,q. Our main results cover not only the representation of q-Gaussian distribution by van Leeuwen and Maassen [J. Math. Phys. 36, 4743–4756 (1995)] but also of q2-Gaussian and symmetric free Meixner distributions on ℝ. In addition, non-trivial commutation relations satisfied by (α, q)-operators are presented.
We define a natural transformation of certain symmetric probability measures, and show that it brings the Gaussian-law as well as several deformed analogue of it to the Poisson-law or to the corresponding deformed Poisson-law, respectively. An important example is the q-Gaussian-law with its transform being the q-Poisson-law of Saitoh and Yoshida. By analogy we define an even more general class of deformed Poisson distributions, and show that, as in the classical and the q-case, these deformed Poisson-laws can be achieved as the distributions of certain operators.
IntroductionLet
at and
at∗ be respectively annihilation and creation operators at apoint
t∈R .In the theory of white noise operators [23][24], it is known that
at is acontinuous linear operator from
Γu(Ec) , the (Fock) space of test functions over acomplexified nuclear space
Ec , into itself, and at is acontinuous linear operator from
Γu(EC)∗ , the dual space of
Γu(EC) , into itself.In paticular,
at+at∗ and
at+at∗+at∗at+I are cffied the quantum Gaussian white noise and the quantum Poisson white noise, respectively (cf.[11] [24]).These are known to be elemental generalzed qunatum stochastic processes.The main purpose of this work is to examine relationships between classical and quantum white noises from the point of the classical white noise theory of Gaussian [19][20] and Poisson types [13].Then it will be clarified that quantum Gaussian and Poisson white noises are the Fock space realzations of classical Gaussian and Poisson white noises, respectively.We shall discuss them in Section 4. As amatter of fact, one can see that such facts can be proved not only through
J -transform given by (2.4) and the holomorphy, but also through Sx-transform gllven by (3.3) depending on the exponential function
ϕξX .The function
ϕξX determines aunitary isomorphism between Boson Fock space and
L2(E∗,μx) ,
X=G,
P , where
μG and
μP are a Gaussian measure and aPoisson measure on
E∗ , respectively.As is pointed out in Remark 4.3, the choice of
ϕξX (kernel function of
SX -transform)is the essential part to represent the above different quantum noises acting on the same space
Γu(Ec)∗ .In Appendix, some connections between
[6][7] and [10]
wiU be noted.