Affordable Access

Minimal projections onto subspaces of $l^{(n)}_\infty$ of codimension two

Universitat de Barcelona
Publication Date


Let $Y\subset l^{(n)}_\infty$ be one of its subspaces of codimension two. Denote by $\mathcal{P}_Y$ the set of all linear projections going from $l^{(n)}_\infty$ onto $Y$ . Put $$\lambda_Y = inf\{\parallel P\parallel : P\in\mathcal{P}_Y\}.$$ An operator $P_0\in\mathcal{P}_Y$ is called a minimal projection if $\parallel P_0\parallel = \lambda_Y$ . In this note we present a partial solution of the problem of calculation $\lambda_Y$ as well as the problem of calculation of minimal projection. We also characterize the unicity of minimal projection.

There are no comments yet on this publication. Be the first to share your thoughts.