Complete solutions to a Class of 8th Order Polynomial Optimization   Problems
  This paper presents a new class of 8th order canonical polynomials in n-dimensional real space. Based on the sequential canonical dual transformation, all extrema are obtained. The method can be used to solve the associated 7th order nonlinear algebraic equations. Optimality conditions are provided to find both global minimizers and local extrema. Applications are illustrated by examples. 
Timothy K. Gao
math-ph math.MP