Resumen de On the Pythagoras number for polynomials of degree 4 in 5 variables

Santiago Laplagne

• We give an example of a polynomial of degree 4 in 5 variables that is the sum of squares of 8 polynomials and cannot be decomposed as the sum of 7 squares. This improves the current existing lower bound of 7 polynomials for the Pythagoras number p(5, 4).