Exposed extreme rays of the SONC cone
Mareike Dressler, Hongzhi Liao, Vera Roshchina
TL;DR
The paper addresses the structural understanding of the SONC cone by fully characterizing its exposed extreme rays on a finite ground set. It develops a purely combinatorial criterion based on the existence and nature of circuits, and delivers constructive exposing functionals via a graded partition of the ground set. The main contributions are a complete exposition of which extreme rays are exposed or not, along with explicit normals that certify exposure, enabling algorithmic detection. This advances both the theoretical geometry of SONC cones and practical SONC-based certification in polynomial optimization.
Abstract
We provide a complete and explicit characterization of the exposed extreme rays of the cone of sums of nonnegative circuit (SONC) polynomials. The criterion we derive is purely combinatorial and depends only on the existence of certain circuits within the ground set and on the nature of the corresponding extreme ray. Our constructive proofs also yield explicit exposing functionals, offering a basis for algorithmic detection of exposed rays in SONC-based optimization.
