Convex-Cyclic Matrices, Convex-Polynomial Interpolation & Invariant Convex Sets

Nathan S. Feldman; Paul McGuire

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arXiv · 1507.08323

Convex-Cyclic Matrices, Convex-Polynomial Interpolation & Invariant Convex Sets

Nathan S. Feldman·Paul McGuire

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Abstract

We define a convex-polynomial to be one that is a convex combination of the monomials $\{1, z, z^2, \ldots\}$. This paper explores the intimate connection between peaking convex-polynomials, interpolating convex-polynomials, invariant convex sets, and the dynamics of matrices. In particular, we use these intertwined relations to both prove which matrices are convex-cyclic while at the same time proving that we can prescribe the values and a finite number of the derivatives of a convex-polynomial subject to certain natural constraints. These properties are also equivalent to determining those matrices whose invariant closed convex sets are all invariant subspaces. Our characterization of the convex-cyclic matrices gives a new and correct proof of a similar result by Rezaei that was stated and proven incorrectly.

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BibTeX RIS

Nathan S. Feldman, Paul McGuire. 2015-07-29. Convex-Cyclic Matrices, Convex-Polynomial Interpolation & Invariant Convex Sets. https://arxiv.org/abs/1507.08323

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