English

Projective and free matricially normed spaces

Functional Analysis 2017-06-05 v1

Abstract

We study metrically projective and metrically free matricially normed spaces. We describe these spaces in terms of a special space M^n\widehat M_n, the space of n×nn\times n matrices, endowed with a special matrix-norm. We show that metrically free matricially normed spaces are matricial 1\ell_1-sums of some distinguished families of matricially normed spaces M^n\widehat M_n, whereas metrically projective matricially normed spaces are complete direct summands of matricial 1\ell_1-sums of arbitrary families of the spaces M^n\widehat M_n. At the end we specify the underlying normed space of M^n\widehat M_n and show that the spaces M^n\widehat M_n; n>1n>1 do not belong to any of the classes LpL^p; p[1,]p\in [1,\infty], introduced by Effros and Ruan. However, in a certain sense the behavior of M^n\widehat M_n resembles that of L1L^1-spaces.

Cite

@article{arxiv.1706.00627,
  title  = {Projective and free matricially normed spaces},
  author = {A. Ya. Helemskii},
  journal= {arXiv preprint arXiv:1706.00627},
  year   = {2017}
}
R2 v1 2026-06-22T20:07:19.317Z