5 papers
Automorphic Nelson Dilations for Contractions and Invariant Subspace Tracking
Kelly Bickel, J. E. Pascoe, Ryan Tully-Doyle
Given an strictly contractive matrix , an (automorphic) Nelson dilation of is a certain type of analytic matrix-valued function on the unit disk w…
Two-Variable Compressions of Shifts, Toeplitz Operators, and Numerical Ranges
Kelly Bickel, Katie Quertermous, Matina Trachana
This paper studies two-variable compressions of shifts associated to rational inner functions on the bidisk; these generalize the classical compressions of the shift associated to…
Pairs of Clark Unitary Operators on the Bidisk and their Taylor Joint Spectra
Palak Arora, Kelly Bickel, Constanze Liaw +1
We develop a Clark theory for commuting compressed shift operators on model spaces associated with inner functions on the bidisk, which exhibits both similarities and m…
Stable Polynomials via Undirected Colored Graphs
Kelly Bickel, Yang Hong
This paper initiates a systematic study of connections between undirected colored graphs and associated two-variable stable polynomials obtained via Cauchy transform-type formulas.…
Stable polynomials and admissible numerators in product domains
Kelly Bickel, Greg Knese, James Eldred Pascoe +1
Given a polynomial with no zeros in the polydisk, or equivalently the poly-upper half-plane, we study the problem of determining the ideal of polynomials with the property…