SPLD polynomial optimization and bounded degree SOS hierarchies
Liguo Jiao, Jae Hyoung Lee, Nguyen Bui Nguyen Thao
TL;DR
The paper defines separable plus lower-degree (SPLD) polynomials and develops the BSOS-SPLD hierarchy, a bounded-degree SOS framework that exploits SPLD structure to solve global polynomial optimization efficiently. It proves convergence to the global optimum under mild assumptions and shows exact SOS relaxations for SOS-convex SPLD problems, with practical recovery of solutions. Through numerical experiments on nonconvex SPLD test problems and portfolio optimization, the approach demonstrates superior scalability and accuracy compared to the standard BSOS hierarchy, and it also applies to SOS-convex SPLD polynomial regression. The work advances scalable global optimization for structured high-degree polynomials and opens avenues for large-scale SPLD applications and regression tasks in statistics.
Abstract
In this paper, we introduce a new class of structured polynomials, called separable plus lower degree (SPLD) polynomials. The formal definition of an SPLD polynomial, which extends the concept of SPQ polynomials (Ahmadi et al. in Math Oper Res 48:1316--1343, 2023), is provided. A type of bounded degree SOS hierarchy, referred to as BSOS-SPLD, is proposed to efficiently solve optimization problems involving SPLD polynomials. Numerical experiments on several benchmark problems indicate that the proposed method yields better performance than the standard bounded degree SOS hierarchy (Lasserre et al. in EURO J Comput Optim 5:87--117, 2017). An exact SOS relaxation for a class of convex SPLD polynomial optimization problems is proposed. Finally, we present an application of SPLD polynomials to convex polynomial regression problems arising in statistics.
