40 citations · 97 across the 15 of their papers we have counts for
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math.FA2023
On the Operators with Numerical Range in an Ellipse
Jim Agler, Zinaida A. Lykova, N. J. Young
We give new necessary and sufficient conditions for the numerical range of an operator to be a subset of the closed elliptical set $K_δ\subs…
math.FA2020
Exterior products of operators and superoptimal analytic approximation
Dimitrios Chiotis, Zinaida Lykova, Nicholas Young
We give a new algorithm for the construction of the unique superoptimal analytic approximant of a given continuous matrix-valued function on the unit circle, making use of exterior…