Pointwise blow-up of sequences bounded in L1

JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS

卷:263

Article

Lopes, MC ; Lopes, HJN

关键词: integrable functions;    Cantor sets;    Hausdorff dimension;    approximation of solutions;   

DOI  :  10.1006/jmaa.2001.7619

来源: Elsevier

【 摘 要 】

Given a sequence of functions bounded in L-1([0, 1]), is it possible to extract a subsequence that is pointwise bounded almost everywhere? The main objective of this note is to present an example showing that this is not possible in general. We will also prove a pair of positive results. We show that if the sequence of functions consists of multiples of characteristic functions of measurable sets, the answer is yes. We also show that it is always possible to extract a subsequence that is pointwise bounded on a countable, dense set of points. (C) 2001 Academic Press.

【 授权许可】

Free