26 research outputs found

    The Non-Archimedean Theory of Discrete Systems

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    In the paper, we study behavior of discrete dynamical systems (automata) w.r.t. transitivity; that is, speaking loosely, we consider how diverse may be behavior of the system w.r.t. variety of word transformations performed by the system: We call a system completely transitive if, given arbitrary pair a,ba,b of finite words that have equal lengths, the system A\mathfrak A, while evolution during (discrete) time, at a certain moment transforms aa into bb. To every system A\mathfrak A, we put into a correspondence a family FA\mathcal F_{\mathfrak A} of continuous maps of a suitable non-Archimedean metric space and show that the system is completely transitive if and only if the family FA\mathcal F_{\mathfrak A} is ergodic w.r.t. the Haar measure; then we find easy-to-verify conditions the system must satisfy to be completely transitive. The theory can be applied to analyze behavior of straight-line computer programs (in particular, pseudo-random number generators that are used in cryptography and simulations) since basic CPU instructions (both numerical and logical) can be considered as continuous maps of a (non-Archimedean) metric space Z2\mathbb Z_2 of 2-adic integers.Comment: The extended version of the talk given at MACIS-201

    T-functions revisited: New criteria for bijectivity/transitivity

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    The paper presents new criteria for bijectivity/transitivity of T-functions and fast knapsack-like algorithm of evaluation of a T-function. Our approach is based on non-Archimedean ergodic theory: Both the criteria and algorithm use van der Put series to represent 1-Lipschitz pp-adic functions and to study measure-preservation/ergodicity of these

    T-Funtions of several variables: New Criteria for Transitivity

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    The paper presents new criteria for transitivity of T-functions of several variables. Our approach is based on non-Archimedean ergodic theory. The criteria: for any 1-lipschitz ergodic map F: Zpk↦Zpk,  k>1∈N,F:\, \mathbb{Z}^{k}_{p} \mapsto \mathbb{Z}^{k}_{p},\;k>1\in\mathbb{N}, there are 1-lipschitz ergodic map G: Zp↦ZpG:\, \mathbb{Z}_{p} \mapsto \mathbb{Z}_{p} and two bijection HkH_k, Tk,  PT_{k,\;P} that G=Hk∘Tk,  P∘F∘Hk−1andF=Hk−1∘Tk,  P−1∘G∘Hk.G = H_{k} \circ T_{k,\;P}\circ F\circ H^{-1}_{k} \text{and} F = H^{-1}_{k} \circ T_{k,\;P^{-1}}\circ G\circ H_{k}.Comment: arXiv admin note: text overlap with arXiv:1112.5089 by other author

    Nonstandard Methods in Ramsey Theory and Combinatorial Number Theory

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    The goal of this present manuscript is to introduce the reader to the nonstandard method and to provide an overview of its most prominent applications in Ramsey theory and combinatorial number theory.Comment: 126 pages. Comments welcom
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