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Proceedings of the American Mathematical Society
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Weakly null sequences with an unconditional subsequence

Author(s): Alexander D. Arvanitakis
Journal: Proc. Amer. Math. Soc. 134 (2006), 67-74.
MSC (2000): Primary 05D10, 46B15
Posted: August 12, 2005
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Abstract | References | Similar articles | Additional information

Abstract: In the present paper we provide sufficient conditions such that a normalized pointwise convergent to zero sequence in $C(K, X)$ with $K$ a compact space and $X$ a Banach space has an unconditional subsequence.

As a consequence we obtain that any such sequence of functions $(f_n)_n$ with finite and uniformly bounded cardinality of their range admits an unconditional subsequence.


References:

1.
S. A. Argyros, G. Godefroy, and H. P. Rosenthal.
Descriptive set theory and Banach spaces.
In Handbook of the geometry of Banach spaces, Vol. 2, pages 1007-1069. North-Holland, Amsterdam, 2003. MR 1999190 (2004g:46002)

2.
S. A. Argyros, S. Mercourakis, and A. Tsarpalias.
Convex unconditionality and summability of weakly null sequences.
Israel J. Math., 107:157-193, 1998. MR 1658551 (99m:46021)

3.
E. Ellentuck.
A new proof that analytic sets are Ramsey.
J. Symbolic Logic, 39:163-165, 1974. MR 0349393 (50:1887)

4.
J. Elton.
Weakly null normalized sequences in Banach spaces.
Ph.D. thesis, 1978.

5.
F. Galvin and K. Prikry.
Borel sets and Ramsey's theorem.
J. Symbolic Logic, 38:193-198, 1973. MR 0337630 (49:2399)

6.
I. Gasparis, E Odell, and B. Wahl.
Weakly null sequences in the Banach space $C(K).$
Preprint.

7.
J. Lopez-Abad and S. Todorcevic.
Unconditional subsequences of weakly null sequences.
In preparation, 2004.

8.
B. Maurey and H. P. Rosenthal.
Normalized weakly null sequence with no unconditional subsequence.
Studia Math., 61(1):77-98, 1977. MR 0438091 (55:11010)

9.
E. Odell.
Applications of Ramsey theorems to Banach space theory.
In Notes in Banach spaces, pages 379-404. Univ. Texas Press, Austin, Tex., 1980. MR 0606226 (83g:46018)

10.
J. Silver.
Every analytic set is Ramsey.
J. Symbolic Logic, 35:60-64, 1970. MR 0332480 (48:10807)

11.
S. Todorcevic.
High-dimensional Ramsey theory.
Preprint, CRM, 2004.


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Additional Information:

Alexander D. Arvanitakis
Affiliation: Department of Mathematics, National Technical University of Athens, Zografou Campus, 15780, Athens, Greece
Email: aarva@math.ntua.gr

DOI: 10.1090/S0002-9939-05-07948-7
PII: S 0002-9939(05)07948-7
Received by editor(s): April 2, 2004
Received by editor(s) in revised form: September 1, 2004
Posted: August 12, 2005
Additional Notes: The author was partially supported by EPEAEK research program Pythagoras
Communicated by: N. Tomczak-Jaegermann
Copyright of article: Copyright 2005, American Mathematical Society
The copyright for this article reverts to public domain after 28 years from publication.


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