Noncommutative partially convex rational functions
Michael Jury
University of Florida, Gainesville, USAIgor Klep
University of Ljubljana, SloveniaMark E. Mancuso
Lafayette College, Easton, USAScott McCullough
University of Florida, Gainesville, USAJames Eldred Pascoe
University of Florida, Gainesville, USA
Abstract
Motivated by classical notions of bilinear matrix inequalities (BMIs) and partial convexity, this article investigates partial convexity for noncommutative functions. It is shown that noncommutative rational functions that are partially convex admit novel butterfly-type realizations that necessitate square roots. A strengthening of partial convexity arising in connection with BMIs – -convexity – is also considered. A characterization of -convex polynomials is given.
Cite this article
Michael Jury, Igor Klep, Mark E. Mancuso, Scott McCullough, James Eldred Pascoe, Noncommutative partially convex rational functions. Rev. Mat. Iberoam. 38 (2022), no. 3, pp. 731–759
DOI 10.4171/RMI/1304