Spectra of Cantor measures
Autor: | Xin-Rong Dai |
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Rok vydání: | 2016 |
Předmět: |
Discrete mathematics
General Mathematics 010102 general mathematics Spectrum (functional analysis) Structure (category theory) 010103 numerical & computational mathematics Characterization (mathematics) Lambda 01 natural sciences Measure (mathematics) Spectral line Combinatorics Tree (descriptive set theory) Integer 0101 mathematics Mathematics |
Zdroj: | Mathematische Annalen. 366:1621-1647 |
ISSN: | 1432-1807 0025-5831 |
DOI: | 10.1007/s00208-016-1374-5 |
Popis: | The Cantor measures \(\mu _{q, b}\) with \(2 = q, b/q \in {\mathbb Z}\) are few of known singular continuous measures that admits a spectrum. The spectra of Cantor measures \(\mu _{q, b}\) are not unique and their structure is not well-studied. It has been observed that maximal orthogonal sets of the Cantor measure \(\mu _{q, b}\) have tree structure and they can be built by selecting maximal tree appropriately. A challenging problem is when a maximal orthogonal set becomes a spectrum. In this paper, we introduce a measurement on the tree structure associated with a maximal orthogonal set \(\Lambda \) of the Cantor measure \(\mu _{q, b}\), and we use boundedness and linear increment of that measurement to justify whether \(\Lambda \) is a spectrum or not. As applications of our justification, we provide a characterization for the expanding set \(K\Lambda \) of a spectrum \(\Lambda \) to be a spectrum again. Furthermore, we construct a spectrum \(\Lambda \) such that for some integer K, the shrinking set \(\Lambda /K\) is a maximal orthogonal set but not a spectrum. |
Databáze: | OpenAIRE |
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