Nonlinear algebra and applications

P Breiding, TÖ Çelik, T Duff, A Heaton, A Maraj… - arxiv preprint arxiv …, 2021 - arxiv.org
We showcase applications of nonlinear algebra in the sciences and engineering. Our review
is organized into eight themes: polynomial optimization, partial differential equations …

Moment ratio inequality of bivariate Gaussian distribution and three-dimensional Gaussian product inequality

O Russell, W Sun - Journal of Mathematical Analysis and Applications, 2023 - Elsevier
We prove the three-dimensional Gaussian product inequality (GPI) E [X 1 2 X 2 2 m 2 X 3 2
m 3]≥ E [X 1 2] E [X 2 2 m 2] E [X 3 2 m 3] for any centered Gaussian random vector (X 1, X …

Using sums-of-squares to prove Gaussian product inequalities

O Russell, W Sun - Dependence Modeling, 2024 - degruyter.com
The long-standing Gaussian product inequality (GPI) conjecture states that E [∏ j= 1 n∣ X
j∣ yj]≥∏ j= 1 n E [∣ X j∣ yj] for any centered Gaussian random vector (X 1,…, X n) and …

Identifiability in continuous Lyapunov models

P Dettling, R Homs, C Améndola, M Drton… - SIAM Journal on Matrix …, 2023 - SIAM
The recently introduced graphical continuous Lyapunov models provide a new approach to
statistical modeling of correlated multivariate data. The models view each observation as a …

Matroids on eight elements with the half-plane property and related concepts

M Kummer, B Sert - SIAM Journal on Discrete Mathematics, 2023 - SIAM
We classify all matroids with at most eight elements that have the half-plane property, and
we provide a list of some matroids on nine elements that have and that do not have the half …

Exact semidefinite programming bounds for packing problems

M Dostert, D De Laat, P Moustrou - SIAM Journal on Optimization, 2021 - SIAM
In this paper we give an algorithm to round the floating point output of a semidefinite
programming solver to a solution over the rationals or a quadratic extension of the rationals …

Symmetric nonnegative functions, the tropical Vandermonde cell and superdominance of power sums

J Acevedo, G Blekherman, S Debus… - arxiv preprint arxiv …, 2024 - arxiv.org
We study nonnegative and sums of squares symmetric (and even symmetric) functions of
fixed degree. We can think of these as limit cones of symmetric nonnegative polynomials …

Time-dependent moments from partial differential equations and the time-dependent set of atoms

RE Curto, PJ di Dio, M Korda, V Magron - arxiv preprint arxiv:2211.04416, 2022 - arxiv.org
We study the time-dependent moments and associated polynomials arising from the partial
differential equation $\partial_t f=\nu\Delta f+ g\cdot\nabla f+ h\cdot f $, and consider in detail …

Bad projections of the PSD cone

Y Jiang, B Sturmfels - Collectanea mathematica, 2021 - Springer
The image of the cone of positive semidefinite matrices under a linear map is a convex cone.
Pataki characterized the set of linear maps for which that image is not closed. The Zariski …

The Lorenz system as a gradient-like system

JP Parker - arxiv preprint arxiv:2401.10649, 2024 - arxiv.org
We formulate, for continuous-time dynamical systems, a sufficient condition to be a gradient-
like system, ie that all bounded trajectories approach stationary points and therefore that …