Weighted projections and Riesz frames

Abstract

Let $\mathcal{H}$ be a (separable) Hilbert space and $\{e_k{\}}_{k\ge 1}$ a fixed orthonormal basis of $\mathcal{H}$. Motivated by many papers on scaled projections, angles of subspaces and oblique projections, we define and study the notion of compatibility between a subspace and the abelian algebra of diagonal operators in the given basis. This is used to refine previous work on scaled projections, and to obtain a new characterization of Riesz frames.

23 pages, to appear in Linear Algebra and its Applications

References in corpus (1)

• Oblique projections and Schur complements