Type: Article
Publication Date: 2014-05-07
Citations: 5
DOI: https://doi.org/10.2140/apde.2014.7.97
We show that any N -dimensional linear subspace of L 2 )ޔ( admits an orthonormal system such that the L 2 norm of the square variation operator V 2 is as small as possible.When applied to the span of the trigonometric system, we obtain an orthonormal system of trigonometric polynomials with a V 2 operator that is considerably smaller than the associated operator for the trigonometric system itself.