Available in electronic format
Available in print format
Proceedings of the American Mathematical Society
Proceedings of the American Mathematical Society
ISSN 1088-6826 (e) ISSN 0002-9939 (p)
     

Subsystems of the Walsh orthogonal system whose multiplicative completions are quasibases for $L^{p}[0,1]$, $1\leq p < +\infty $

Author(s): M. G. Grigorian; Robert E. Zink
Journal: Proc. Amer. Math. Soc. 131 (2003), 1137-1149.
MSC (2000): Primary 42C10
Posted: July 25, 2002
Retrieve article in: PDF DVI PostScript

Abstract | References | Similar articles | Additional information

Abstract: If one discards some of the elements from the Walsh family, an ancient example of a system that serves as a Schauder basis for each of the $L^{p}$-spaces, with $1< p<+\infty $, the residual system will not be a Schauder basis for any of those spaces. Nevertheless, Price has shown that each member of a large class of such subsystems is complete on subsets of $[0,1]$ that have measure arbitrarily close to $1$. In the present work, it is shown that subsystems of this kind can be multiplicatively completed in such a way that the resulting systems are quasibases for each space $L^{p}[0,1]$, $1\le p<+\infty $, from which the earlier completeness result follows as a corollary.


References:

1.
R. P. Boas and Harry Pollard, The multiplicative completion of sets of functions, Bull. Amer. Math. Soc. 54 (1948), 518-522. MR 10:189b

2.
Ben-Ami Braun, On the multiplicative completion of certain basic sequences in $L^{p}$, $1<p<\infty $, Trans. Amer. Math. Soc. 176 (1973), 499-508. MR 47:2331

3.
Bernard R. Gelbaum, Notes on Banach spaces and bases, An. Acad. Brasil 30 (1958), 29-36. MR 20:5419

4.
Casper Goffman and Daniel Waterman, Basic sequences in the space of measurable functions, Proc. Amer. Math. Soc. 11 (1960), 211-213. MR 22:2886

5.
M. Zh. Grigoryan, Convergence almost everywhere of Walsh-Fourier series of integrable functions, Izv. Akad. Nauk. Arm. SSR Ser. Math. 18 (4) (1983), 291-304 (Russian). MR 85a:42034

6.
M. G. Grigorian, Convergence of Walsh-Fourier series in the $L^{1}$ metric and almost everywhere; English translation in. Soviet Math. Izv. VUZ 34 (11) (1990), 9-20.

7.
K. S. Kazarian and Robert E. Zink, Some ramifications of a theorem of Boas and Pollard concerning the completion of a set of functions in $L^{2}$, Trans. Amer. Math. Soc. 349 (1997), 4367-4383. MR 99d:42050

8.
N. Levinson, Gap and Density Theorems, Amer. Math. Soc. Colloq. Publ. 26, Amer. Math. Soc., Providence, 1940. MR 2:180d

9.
R. E. A. C. Paley, A remarkable set of orthogonal functions, Proc. London Math. Soc. 34 (1932), 241-279.

10.
J. J. Price, A density theorem for Walsh functions, Proc. Amer. Math. Soc. 18 (1967), 209-211. MR 35:656

11.
J. J. Price and Robert E. Zink, On sets of functions that can be multiplicatively completed, Ann. Math. 82 (1965), 139-145. MR 31:1349

12.
Ivan Singer, Bases in Banach Spaces II, Springer Verlag, Berlin, Heidelberg, New York, 1981. MR 82k:46024

13.
A. A. Talalyan, On the convergence almost everywhere of subsequences of partial sums of general orthogonal series, Izv. Akad. Nauk. Arm. SSR Izv. Fiz.-Mat. Tehn Nauki 10 (1957), 17-34. MR 19:742b

14.
-, The representation of measurable functions by series; English translation in Russian Math. Surveys 15 (1960), 77-136.


Similar Articles:

Retrieve articles in Proceedings of the American Mathematical Society with MSC (2000): 42C10

Retrieve articles in all Journals with MSC (2000): 42C10


Additional Information:

M. G. Grigorian
Affiliation: Department of Mathematics, Erevan State University, Alex Manoogian Str., 375049 Yerevan, Armenia
Email: gmarting@ysu.am

Robert E. Zink
Affiliation: Department of Mathematics, Purdue University, West Lafayette, Indiana 47907-1968
Email: zink@math.purdue.edu

DOI: 10.1090/S0002-9939-02-06618-2
PII: S 0002-9939(02)06618-2
Received by editor(s): August 22, 2001
Received by editor(s) in revised form: November 2, 2001
Posted: July 25, 2002
Communicated by: Andreas Seeger
Copyright of article: Copyright 2002, American Mathematical Society


  AMS Website Logo Small Comments: webmaster@ams.org
© Copyright 2008, American Mathematical Society
Privacy Statement
Search the AMSPowered by Google