Polynomials that preserve nonnegative matrices

In further pursuit of a solution to the celebrated nonnegative inverse eigenvalue problem, Loewy and London ((1978/1979) [8]) posed problem characterizing all polynomials that preserve matrices fixed order. If Pn denotes set n-by-n matrices, then it is clear with coefficients belong Pn. However, known contains negative entries. this work, novel results for respect belonging Along way, generalization even-part odd-part are given shown be equivalent another construction appeared in literature. Implications research discussed.