2,685 research outputs found
Finite-State Dimension and Real Arithmetic
We use entropy rates and Schur concavity to prove that, for every integer k
>= 2, every nonzero rational number q, and every real number alpha, the base-k
expansions of alpha, q+alpha, and q*alpha all have the same finite-state
dimension and the same finite-state strong dimension. This extends, and gives a
new proof of, Wall's 1949 theorem stating that the sum or product of a nonzero
rational number and a Borel normal number is always Borel normal.Comment: 15 page
Equidistribution from Fractals
We give a fractal-geometric condition for a measure on [0,1] to be supported
on points x that are normal in base n, i.e. such that the sequence x,nx,n^2
x,... equidistributes modulo 1. This condition is robust under C^1 coordinate
changes, and it applies also when n is a Pisot number and equidistribution is
understood with respect to the beta-map and Parry measure. As applications we
obtain new results (and strengthen old ones) about the prevalence of normal
numbers in fractal sets, and new results on measure rigidity, specifically
completing Host's theorem to multiplicatively independent integers and proving
a Rudolph-Johnson-type theorem for certain pairs of beta transformations.Comment: 46 pages. v3: minor corrections and elaboration
Unexpected distribution phenomenon resulting from Cantor series expansions
We explore in depth the number theoretic and statistical properties of
certain sets of numbers arising from their Cantor series expansions. As a
direct consequence of our main theorem we deduce numerous new results as well
as strengthen known ones.Comment: 32 page
Visual art inspired by the collective feeding behavior of sand-bubbler crabs
Sand--bubblers are crabs of the genera Dotilla and Scopimera which are known
to produce remarkable patterns and structures at tropical beaches. From these
pattern-making abilities, we may draw inspiration for digital visual art. A
simple mathematical model is proposed and an algorithm is designed that may
create such sand-bubbler patterns artificially. In addition, design parameters
to modify the patterns are identified and analyzed by computational aesthetic
measures. Finally, an extension of the algorithm is discussed that may enable
controlling and guiding generative evolution of the art-making process
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