A necessary and sufficient condition for the positivity of apolynomial in several real variables described over ahyperrectangle

摘要

A necessary and sufficient condition for the positivity of apolynomial in two real variables described over a square is given. Thisresult can be generalized to the case of several variables. The resultplays a critical role in the development of necessary and sufficientconditions for the robust stability of interval parameter matrices andpolynomials