3 papers
math.SP2022
On the Spectral Theory of Linear Differential-Algebraic Equations with Periodic Coefficients
Bader Alshammari, Aaron Welters
In this paper, we consider the spectral theory of linear differential-algebraic equations (DAEs) for periodic DAEs in canonical form, i.e., \begin{equation*} J \frac{df}{dt}+Hf=λWf…
math.CV2021
A Short Proof of the Symmetric Determinantal Representation of Polynomials
Anthony Stefan, Aaron Welters
We provide a short proof of the theorem that every real multivariate polynomial has a symmetric determinantal representation, which was first proved in J. W. Helton, S. A. McCullou…
math.CV2020
Extension of the Bessmertnyi Realization Theorem for Rational Functions of Several Complex Variables
Anthony Stefan, Aaron Welters
We prove a realization theorem for rational functions of several complex variables which extends the main theorem of M. Bessmertnyi, "On realizations of rational matrix functions o…