A lower bound for the projection constant of \(II_ 2\)
Let \(II_ n\) denote the space of polynomials of degree not greater than n, regarded as a subspace of C[-1,1]. The exact projection constant of \(II_ 2\) remains unknown. In this note the author shows that the constant is not less then 1.2158.
scientific article; zbMATH DE number 4069490