activity
20152026
collaborators

7 papers

math.OA2026

Skew fields of non-commutative meromorphic functions affiliated to finite operator algebras

Méric L. Augat, Robert T. W. Martin, Maximilian Tornes +1

We embed skew fields of meromorphic functions in several non-commuting variables into the topological algebra of closed linear operators affiliated to a finite von Neumann alge…

math.FA2026

A non-commutative de Branges-Rovnyak model for row contractions

Robert T. W. Martin, Jeet Sampat

We extend the de Branges-Rovnyak model for completely non-coisometric (CNC) linear contractions on a Hilbert space to the non-commutative multivariate setting of CNC row contractio…

math.FA2025

Operator realizations about a matrix-centre

Ali Karoobi, Robert T. W. Martin, Maximilian Tornes

We develop a general theory of operator realizations, or ``linear representations" of analytic functions in several non-commuting variables about a matrix-centre. In particular we…

math.OA2025

Rings of non-commutative functions and their fields of fractions

Méric L. Augat, Robert T. W. Martin, Eli Shamovich

Semi-free ideal rings, or semifirs, were introduced by Paul M. Cohn to study universal localizations in the non-commutative setting. We provide new examples of semifirs consisting…

math.DS2024

Invariant Measures in Time-Delay Coordinates for Unique Dynamical System Identification

Jonah Botvinick-Greenhouse, Robert Martin, Yunan Yang

While invariant measures are widely employed to analyze physical systems when a direct study of pointwise trajectories is intractable, e.g., due to chaos or noise, they cannot uniq…

math.FA2024

Operator realizations of non-commutative analytic functions

Méric L. Augat, Robert T. W. Martin, Eli Shamovich

A realization is a triple, , consisting of a tuple, , , of bounded linear operators on a separable, complex Hilbert space, $…

quant-ph2015

Quantum uncertainty and the spectra of symmetric operators

R. T. W. Martin, A. Kempf

In certain circumstances, the uncertainty, , of a quantum observable, , can be bounded from below by a finite overall constant , \emph{i.e.}, , for…