Non-Commutative Markov Chains and Multi-Analytic Operators (2009)
We study a model of repeated interaction between quantum systems which can be thought of as a non-commutative Markov chain. It is shown that there exists an outgoing Cuntz scattering system...
Linear Quantum Feedback Networks (2008)
Gough, John, Gohm, Rolf, Yanagisawa, Masahiro
The mathematical theory of quantum feedback networks has recently been developed [J. Gough and M. R. James, e-print arXiv:0804.3442v2] for general open quantum dynamical systems interacting with...
Linear quantum feedback networks (2008)
Gough, John, Gohm, Rolf, Yanagisawa, Masahiro
The mathematical theory of quantum feedback networks has recently been developed [J. Gough and M. R. James, e-print arXiv:0804.3442v2] for general open quantum dynamical systems interacting with...
Noncommutative independence from the braid group $B_\infty$ (2008)
We introduce `braidability' as a new symmetry for (infinite) sequences of noncommutative random variables related to representations of the braid group $B_\infty$. It provides an extension of...
Characteristic Functions of Liftings (2007)
We introduce characteristic functions for certain contractive liftings of row contractions. These are multi-analytic operators which classify the liftings up to unitary equivalence and provide a kind...
Characteristic function for ergodic tuples (2007)
Motivated by a result on weak Markov dilations, we define a notion of characteristic function for ergodic and coisometric row contractions with a one-dimensional invariant subspace for the adjoints....
Non-commutative symbolic coding (2006)
Gohm, Rolf, Kummerer, B., Lang, T.
We give a non-commutative generalization of classical symbolic coding in the presence of a synchronizing word. This is done by a scattering theoretical approach. Classically, the existence of a...
Characteristic Functions for Ergodic Tuples (2005)
Motivated by a result on weak Markov dilations, we define a notion of characteristic function for ergodic and coisometric row contractions with a one-dimensional invariant subspace for the adjoints....
Constructing extensions of CP-maps via tensor dilations with rhe help of von Neumann modules (2005)
We apply Hilbert module methods to show that normal completely positive maps admit weak tensor dilations. Appealing to a duality between weak tensor dilations and extensions of CP-maps, we get an...
Decompositions of Beurling Type for E_0-Semigroups (2004)
We define tensor product decompositions of $E_0$-semigroups with a structure analogous to a classical theorem of Beurling. Such decompositions can be characterized by adaptedness and exactness of...
Constructing Extensions of CP-Maps via Tensor Dilations with the Help of Von Neumann Modules (2003)
We apply Hilbert module methods to show that normal completely positive maps admit weak tensor dilations. Appealing to a duality between weak tensor dilations and extensions of CP-maps, we get an...
A probabilistic index for completely positive maps and an application (2003)
The probabilistic index of a completely positive map is defined in analogy with a formula of M. Pimsner and S. Popa for conditional expectations. As an application, we describe a new strategy for...
Greifswald, University, Habil.-Schr., 2003.