Representations of non-negative polynomials having finitely many zeros
Consider a compact subset of real -space defined by polynomial inequalities . For a polynomial non-negative on , natural sufficient conditions are given (in terms of first and second derivatives at the zeros of in ) for to have a presentation of the form , a sum of squares of polynomials. The conditions are much less restrictive than the conditions given by Scheiderer in [11, Cor. 2.6]. The proof uses Scheiderer’s main theorem in [11] as well as arguments from quadratic form theory...