Remote Access Transactions of the American Mathematical Society
Green Open Access

Transactions of the American Mathematical Society

ISSN 1088-6850(online) ISSN 0002-9947(print)



An analogue of Cobham’s theorem for fractals

Authors: Boris Adamczewski and Jason Bell
Journal: Trans. Amer. Math. Soc. 363 (2011), 4421-4442
MSC (2010): Primary 28A80, 11B85
Published electronically: March 4, 2011
MathSciNet review: 2792994
Full-text PDF Free Access

Abstract | References | Similar Articles | Additional Information

Abstract: We introduce the notion of $k$-self-similarity for compact subsets of $\mathbb {R}^n$ and show that it is a natural analogue of the notion of $k$-automatic subsets of integers. We show that various well-known fractals such as the triadic Cantor set, the Sierpiński carpet or the Menger sponge turn out to be $k$-self-similar for some integers $k$. We then prove an analogue of Cobham’s theorem for compact sets of $\mathbb R$ that are self-similar with respect to two multiplicatively independent bases $k$ and $\ell$. Namely, we show that $X$ is both a $k$- and an $\ell$-self-similar compact subset of $\mathbb {R}$ if and only if it is a finite union of closed intervals with rational endpoints.

References [Enhancements On Off] (What's this?)


Similar Articles

Retrieve articles in Transactions of the American Mathematical Society with MSC (2010): 28A80, 11B85

Retrieve articles in all journals with MSC (2010): 28A80, 11B85

Additional Information

Boris Adamczewski
Affiliation: CNRS, Université de Lyon, Université Lyon 1, Institut Camille Jordan, 43 boulevard du 11 novembre 1918, 69622 Villeurbanne Cedex, France
MR Author ID: 704234

Jason Bell
Affiliation: Department of Mathematics, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6
MR Author ID: 632303

Received by editor(s): July 5, 2009
Received by editor(s) in revised form: January 28, 2010, and March 23, 2010
Published electronically: March 4, 2011
Additional Notes: The first author was supported by the ANR through the project “DyCoNum”–JCJC06 134288. He also thanks Jean-Paul Allouche for pointing out relevant references.
The second author thanks NSERC for its generous support.
Article copyright: © Copyright 2011 American Mathematical Society
The copyright for this article reverts to public domain 28 years after publication.