The 2-summing norm of
computed with n vectors
Abstract
The 2-summing norm of an n-dimensional Banach space computed with n vectors is known to belong between
and
. It is shown that the 2-summing norm of real
computed with three vectors is 5/3. Some lower estimates for 2-summing norms of
computed with n vectors are stated, which are considerably better than universal ones and are based on the existence of certain block designs or Hadamard matrices.
![n<sup>1/2</sup>/√{2}](http://siba-ese.unisalento.it/plugins/generic/latexRender/cache/2737b75033769c6662c39bb6cfdfa8a1.png)
![n<sup>1/2</sup>](http://siba-ese.unisalento.it/plugins/generic/latexRender/cache/cbbc7713a23870da84554efa068b0c82.png)
![l<sub>1</sub><sup>3</sup>](http://siba-ese.unisalento.it/plugins/generic/latexRender/cache/10a1b185366da8904956531a281fa81b.png)
![l<sub>p</sub><sup>n</sup>](http://siba-ese.unisalento.it/plugins/generic/latexRender/cache/d49e94490ea9f3bfc726c16f6b742b38.png)
DOI Code:
10.1285/i15900932v14n1p81
Full Text: PDF