Positive operators and Hausdorff dimension of invariant sets
Positive operators and Hausdorff dimension of invariant sets
复制标题
正算子和不变集的豪斯多夫维数
DOI:
10.1090/s0002-9947-2011-05484-x
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发表时间:
2012
影响因子:
1.3
通讯作者:
S. Lunel
中科院分区:
文献类型:
--
作者:
R. Nussbaum;A. Priyadarshi;S. Lunel
. In this paper we obtain theorems which give the Hausdorff dimension of the invariant set for a finite family of contraction mappings which are “infinitesimal similitudes” on a complete, perfect metric space. Our work gen-eralizes the graph-directed construction of Mauldin and Williams (1988) and is related in its general setting to results of Schief (1996), but differs crucially in that the mappings need not be similitudes. We use the theory of positive lin- ear operators and generalizations of the Krein-Rutman theorem to characterize the Hausdorff dimension as the unique value of σ > 0 for which r ( L σ ) = 1, where L σ , σ > 0, is a naturally associated family of positive linear operators and r ( L σ ) denotes the spectral radius of L σ . We also indicate how these results can be generalized to countable families of infinitesimal similitudes. The intent here is foundational: to derive a basic formula in its proper generality and to emphasize the utility of the theory of positive linear operators in this setting. Later work will explore the usefulness of the basic theorem and its functional analytic setting in studying questions about Hausdorff dimension.