4 papers
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…
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…
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…
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…