Kharitonov region

A Kharitonov region is a concept in mathematics. It arises in the study of the stability of polynomials.

Let $$D$$ be a simply-connected set in the complex plane and let $$P$$ be the polynomial family.

$$D$$ is said to be a Kharitonov region if


 * $$V_T^n(V_S^n)$$

is a subset of $$P.$$ Here, $$V_T^n$$ denotes the set of all vertex polynomials of complex interval polynomials $$(T^n)$$ and $$V_S^n$$ denotes the set of all vertex polynomials of real interval polynomials $$(S^n).$$