5 citations · 9 across the 7 of their papers we have counts for
13 papers
Orthogonal polynomials in several non-commuting variables. II
T. Banks, T. Constantinescu
In this paper we continue to investigate a certain class of Hankel-like positive definite kernels using their associated orthogonal polynomials. The main result of this paper is ab…
Tensor algebras and displacement structure. IV. Invariant kernels
T. Banks, T. Constantinescu, Nermine El-Sissi
In this paper we investigate the class of invariant positive definite kernels on the free semigroup on N generators. We provide a combinatorial description of the positivity of the…
Relations on noncommutative variables and associated orthogonal polynomials
T. Banks, T. Constantinescu, J. L. Johnson
This semi-expository paper surveys results concerning three classes of orthogonal polynomials: in one non-hermitian variable, in several isometric non-commuting variables, and in s…
Parametrization of Quantum States and Channels
T. Constantinescu, V. Ramakrishna
In this manuscript, a parametrization of positive matrices together with some of its many applications in quantum information theory is given.
Tensor Algebras and Displacement Structure. III. Asymptotic properties
M. Barakat, T. Constantinescu
We continue to investigate some classes of Szegö type polynomials in several variables. We focus on asymptotic properties of these polynomials and we extend several classical resul…
Note on purifications of a qubit
Tiberiu Constantinescu, Viswanath Ramakrishna
This work provides a parametrization of the set of purifications of a 2x2 mixed state, and joint purifications (if any) of a given pair of mixed 2x2 states. The former is parametri…