Random Generators and Normal Numbers
Bailey, David H. ; Crandall, Richard E.
Experiment. Math., Tome 11 (2002) no. 3, p. 527-546 / Harvested from Project Euclid
Pursuant to the authors' previous chaotic-dynamical model for random digits of fundamental constants, we investigate a complementary, statistical picture in which pseudorandom number generators (PRNGs) are central. Some rigorous results are achieved: We establish b-normality for constants of the form $\sum_i 1/(b^{m_i} c^{n_i})$ for certain sequences $(m_i), (n_i)$ of integers. This work unifies and extends previously known classes of explicit normals. We prove that for coprime $b,c>1$ the constant $\alpha_{b,c} = \sum_{n = c, c^2, c^3,\dots} 1/(n b^n)$ is b-normal, thus generalizing the Stoneham class of normals. Our approach also reproves b-normality for the Korobov class $\beta_{b,c,d}$, for which the summation index n above runs instead over powers $c^d, c^{d^2}, c^{d^3}, \dots$ with $d>1$. Eventually we describe an uncountable class of explicit normals that succumb to the PRNG approach. Numbers of the $\alpha, \beta$ classes share with fundamental constants such as $\pi, \; \log 2$ the property that isolated digits can be directly calculated, but for these new classes such computation tends to be surprisingly rapid. For example, we find that the googol-th (i.e., $10^{100}$-th) binary bit of $\alpha_{2,3}$ is 0. We also present a collection of other results---such as digit-density results and irrationality proofs based on PRNG ideas---for various special numbers.
Publié le : 2002-05-14
Classification:  Normal numbers,  transcendental numbers,  pseudo-random number generators,  11K16,  11K06,  11J81,  11K45
@article{1057864662,
     author = {Bailey, David H. and Crandall, Richard E.},
     title = {Random Generators and Normal Numbers},
     journal = {Experiment. Math.},
     volume = {11},
     number = {3},
     year = {2002},
     pages = { 527-546},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1057864662}
}
Bailey, David H.; Crandall, Richard E. Random Generators and Normal Numbers. Experiment. Math., Tome 11 (2002) no. 3, pp.  527-546. http://gdmltest.u-ga.fr/item/1057864662/