If z is a function from the real line R′ to a real Hilbert space X then the covariance function ϱ of z is defined by ϱ(t, s) ≡ (z(t), z(s)). It is proved that the function (z(·), y) is of bounded ...

OF late years there has arisen a clique of vector analysts who refuse to admit the quaternion to the glorious company of vectors. Their high priest is Prof. Willard Gibbs. His reasons for developing a ...

A new proof is given of the extrapolation theorem of J. L. Rubio de Francia [7]. Unlike the proof in [7], the proof presented here is independent of the theory of vector valued inequalities. Journal ...