Some Ramsey type theorems for normed and quasinormed spaces
Studia Mathematica, Tome 124 (1997) no. 1, pp. 81-100
We prove that every bounded, uniformly separated sequence in a normed space contains a "uniformly independent" subsequence (see definition); the constants involved do not depend on the sequence or the space. The finite version of this result is true for all quasinormed spaces. We give a counterexample to the infinite version in $L_p[0,1]$ for each 0 p 1. Some consequences for nonstandard topological vector spaces are derived.
Keywords:
normed space, Banach space, quasinormed and quasi-Banach space, p-norm, biorthogonal sequence, uniformly independent sequence, irreducible sequence, Ramsey's Theorem, nonstandard analysis
@article{10_4064_sm_124_1_81_100,
author = {C. Ward Henson and and and and },
title = {Some {Ramsey} type theorems for normed and quasinormed spaces},
journal = {Studia Mathematica},
pages = {81--100},
year = {1997},
volume = {124},
number = {1},
doi = {10.4064/sm-124-1-81-100},
language = {en},
url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-124-1-81-100/}
}
TY - JOUR AU - C. Ward Henson AU - AU - AU - AU - TI - Some Ramsey type theorems for normed and quasinormed spaces JO - Studia Mathematica PY - 1997 SP - 81 EP - 100 VL - 124 IS - 1 UR - http://geodesic.mathdoc.fr/articles/10.4064/sm-124-1-81-100/ DO - 10.4064/sm-124-1-81-100 LA - en ID - 10_4064_sm_124_1_81_100 ER -
C. Ward Henson; ; ; ; . Some Ramsey type theorems for normed and quasinormed spaces. Studia Mathematica, Tome 124 (1997) no. 1, pp. 81-100. doi: 10.4064/sm-124-1-81-100
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