Combinatorics, Automata and Number Theory Edited by Valérie Berthé and Michel Rigo Index More Information

Total Page:16

File Type:pdf, Size:1020Kb

Combinatorics, Automata and Number Theory Edited by Valérie Berthé and Michel Rigo Index More Information Cambridge University Press 978-0-521-51597-9 - Combinatorics, Automata and Number Theory Edited by Valérie Berthé and Michel Rigo Index More information Notation index (a, b) (greatest common divisor), b(n) (second difference of p(n)), 474 173 ·(distance to the nearest inte- Bad (set of badly approximable ger), 365, 444 real numbers), 444 σ (width), 11, 142, 507 BAL(σ, τ ), 526 |·| (-adic absolute value), 420 B(x,R) (open ball), 2 f g,2 k (the signed digit −k), 41 g f,2 Bd (symmetrical digit alphabet · 1 (Manhattan norm), 2, 191 with largest digit d), 40 · 2 (Euclidean norm), 2 Bk (language of the numeration ·∞ (maximum norm), 2 in base k), 109 bq,i(w) (coefficients in the decom- 1S (indicator function), 6, 455 position of valS (w)), 120 [w]x (cylinder), 29 N A (set of infinite words), 47 [u] (cylinder), 375 A σ,a (automaton associated with [u]X (cylinder), 375 the morphism σ), 142 BSn (u) (bispecial factors), 171 A (automaton associated σ,a,τ BSn (u) (bispecial factors and ex- with the morphisms σ, τ ), ceptional prefix), 172 142 Adh(L) (adherence of L), 152 χ[u] (characteristic function), 375 Ap (canonical alphabet in base p), Cp (C × A) (the converter be- 37 tween C and A (in base p)), alph(u) (alphabet of u), 6 42 alph(L) (alphabet of L), 14 C(X, Z) (continuous maps), 352 ≤ A n (words of length at most n), CYCLIC(σ) (set of cyclic letters), 4 510 An (words of length n), 4 A+ (free semigroup), 4 d (distance on words), 7 A∗ (free monoid), 4 d−(w) (left valence), 171 + AU (canonical alphabet), 110 d (w) (right valence), 171 © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-0-521-51597-9 - Combinatorics, Automata and Number Theory Edited by Valérie Berthé and Michel Rigo Index More information Notation index 595 δx (Dirac measure), 378, 474 GO(λ) (graph of overlaps), 301 ∂X (boundary), 2 Gσ (prefix-suffix graph), 256 DG(X, T) (dimension group), H 352 c (contracting space), 252 H u ⊕ v (digitwise addition), 42 e (expanding line), 252 u ! v (digitwise subtraction), 42 hσ (contraction), 252 D (set of all p-expansions of reals p ∩ (intersection), 1 in [0, 1)), 50 [[ i, j]] (interval of integers), 2 I e(t)=e2πit, 476 σ (self-replicating multiple e (row vector in which all coordi- tiling), 271 nates equal 1), 512 σ − K (x, y, z), 201 E (w) (left extensions), 171, 231 n K≥ ,1 E+ (w) (right extensions), 171 a K ,2 E(w) (extension type), 172 <a K>a,1 Ey (f1 ,f2 ) (sandwich set), 188 K≤a ,2 en (µ), 387 K (a) (continuant), 429 ε (empty word), 4 m ∼ f g,3 L (u) (factors of length n), 164 E n u (self-similar tiling), 261 Lσ (x, y, z) (centric factors), 197 E X (mean value of random vari- L(u) (factors), 164 able X), 483 Λr , 391 σ1 ,σ2 (monoid generated by Fq (finite field with q elements), 453 σ1 ,σ2 ), 519 Lb , 415 (Fj )j≥0 (Fibonacci sequence), 417 L (set of pairs of real numbers x (floor function), 2 satisfying Littlewood’s con- {x} (fractional part), 2 jecture), 444 u<v(lexicographic order), 9 fw (x) (frequency), 376, 380 u ≤p v (u is a prefix of v), 513 Γc (self-replicating translation u v (lexicographic order), 9 set), 263 u ≺ v (radix order), 9 Γe (self-similar translation set), u v (radix order), 9 261 L≤n (concatenation of at most n [γ,i]∗ (tip), 263 words in L), 14 ∗ → k U [γ,i]g (projected face), 263 L[n n ] (language s.t. (n)= k Gµ,f , 379 n ), 129 Gn (Rauzy graph), 176 L(A) (language recognised by A), Gn (X) (Rauzy graph), 384 16 Gn (x) (Rauzy graph), 384 L(X) (language), 374 GO (graph of overlaps), 300 L(x) (language), 7 © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-0-521-51597-9 - Combinatorics, Automata and Number Theory Edited by Valérie Berthé and Michel Rigo Index More information 596 Notation index Ln (X)(wordsofL of length n), ω(G) (infinite word generated by 374 G), 506 Ln (x) (factors of length n), 7 ω(H), 508 log (logarithm), 3 O(x) (orbit), 28, 374 O log2 (binary logarithm), 3 (x) (orbit closure), 28 Lp (set of all p-expansions), 39 p P L p (set of all -expansions), 86 (probability), 482 q q Lq (language accepted from state P (abelianisation map), 6 q), 117 pu (n) (factor complexity), 164 LSn (u) (left special factors), 171 P(x) (Parikh vector), 191 LSn (u) (left special factors and PER(w)(periodofw), 516 unioccurent prefix), 172 Φ(y) (normal distribution func- L∗ (Kleene star), 14 tion), 487 Ln (power of a language), 14 ϕ (Golden Ratio), 12 Lu (broken line), 253 π (permutation), 391 L(x) (language), 375 πc (projection on the contracting space), 252 M(A) (adjacency matrix), 22 πe (projection on the expanding Mσ (incidence matrix), 22, 191 line), 252 m(w) (bilateral multiplicity), 172 πp (evaluation map), 37 p E(X, T) (ergodic invariant mea- π p (evaluation map in the nu- q q sures), 377 meration system), 86 Mf(s) (Mellin transform of f), P (n) (paths in Bratteli dia- 458 grams), 358 Mβ (minimal polynomial), 62 u ∧ v (longest common prefix), 48 m (Lebesgue measure), 392 x ∧ y (longest common prefix), 7 M(X) (Borel measures), 30 Pσ (prefix-suffix edges), 256 µk (Lebesgue measure), 252 pX (n) (complexity function), 383 M(X, T) (invariant measures), px (n) (complexity function), 8 377 repk (representation in base k), Np (C) (the normaliser over the 109 alphabet C (in base p)), 43 repS (S-representation), 114, 117 N p (p-expansion of N), 39 repq =repS , 118 p q N p ( -expansion of N), 86 repU (U-representation), 109 q q νA,p (normalisation), 26 ρ(A) (spectral radius), 25, 512, 531 O(f), 2 ρ(Σ) (joint spectral radius), 533 o(f), 3 ρˇ(Σ) (joint spectral subradius), Ω(f), 2 534 ω u (concatenation), 8 ρˇt , 533 © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-0-521-51597-9 - Combinatorics, Automata and Number Theory Edited by Valérie Berthé and Michel Rigo Index More information Notation index 597 ρˆt , 531 valS (S-numerical value), 114 ρt , 531 valq =valSq , 118 ρ , 533 v (left eigenvector), 251 t β RSn (u) (right special factors), (V,E,≥) (ordered Bratteli dia- 171 gram), 327 VL (n)=V(n) (number of words s(n) (first difference of p(n)), 173 of length at most n in L), 118 \ (set difference), 1 Vq (n) (number of words of length S (shift map), 374 at most n accepted from q), ,, (shuffle), 129 117 σω (a), 11 Vσ (seed patch), 276 σω (b).σω (a), 11 vσ (Perron–Frobenius eigenvec- S q =(Lq ,A,<), 118 tor), 24, 513 (X, S) (subshift), 374 VX (variance of random variable (Xx ,S) (subshift generated by an X), 490 infinite word), 375 S(X, T) (states of the dimension u (weight of u), 47 group), 362 W(X, S) (weight functions), 379 Wσ (two-piece seed patch), 282 T = R/Z (circle group), 453 Θ(g), 2 XB (infinite path space associ- u˜ (mirror image), 4, 446 ated with an ordered Bratteli L˜ (mirror image), 14 diagram B), 329 max Tλ,π (interval exchange map), 391 XB , 329 min Tσ (central tile), 253 XB , 329 Tσ (i) (subtile), 253 [x,i] (basic formal strand), 291 (T,S,λ) (overlap), 297 ξa (real number whose b-ary ex- [T,S,λ] (overlap equivalence pansion is given by the word class), 298 a), 412 [x,i]g (basic geometric strand), U (lower unit cube), 274 253 uβ (right eigenvector), 251 Xσ (substitutive dynamical sys- UL (n)=U(n) (number of words tem), 32 of length n in L), 118 Z (the zero-automaton in Un,ε, 393 β,d ∪ (union), 1 base β over the alpha- bet B ), 62 Uq (n) (number of words of length d Zp (the evaluator in base p), 40 n accepted from q), 117 p U Z p (the evaluator in base ), 89 q,r(n) (number of directed paths q q Z of length n from q to r), 110 p,d (the zero-automaton in base p over the alpha- vp (n)(p-adic valuation), 474 bet Bd ), 41 © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-0-521-51597-9 - Combinatorics, Automata and Number Theory Edited by Valérie Berthé and Michel Rigo Index More information 598 Notation index ζ(s) (Riemann zeta function), 459 ζf (Fibonacci continued frac- tion), 411 ζa (real number whose continued fraction expansion is given by the word a), 430 ζt (Thue–Morse continued frac- tion), 411 ζ(s, α) (Hurwitz zeta function), 459 © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-0-521-51597-9 - Combinatorics, Automata and Number Theory Edited by Valérie Berthé and Michel Rigo Index More information General index 1-system Angrand, P.-Y., 128 definition, 507 ANS, see abstract numeration Z-balanced, 519 system approximation algorithm a.e., see almost everywhere (k,l)-, 540 abelianisation map, 6 non-existence of, 540 abstract numeration system, 114 Arnoux, P., 8, 319 accessible state, 16 atoms, 330 Adamczewski, B., 423 automatic sequence, 19, 214, 450 additive function, 162, see q- q-automatic, 19, 138, 214, 452 additive automatic word, see automatic adherence, 152 sequence adic, 399 automaton dynamical system, 399 Aho–Corasick, 549 Pascal, 404 B¨uchi, 54 transformation, 324 complete, 17 adjacency matrix, 22 deterministic, 17 Adjan, S.
Recommended publications
  • Numeration 2016
    Numeration 2016 Prague, Czech Republic, May 23–27 2016 Department of Mathematics FNSPE Czech Technical University in Prague Numeration 2016 Prague, Czech Republic, May 23–27 2016 Department of Mathematics FNSPE Czech Technical University in Prague Print: Česká technika — nakladatelství ČVUT Editor: Petr Ambrož [email protected] Katedra matematiky Fakulta jaderná a fyzikálně inženýrská České vysoké učení technické v Praze Trojanova 13 120 00 Praha 2 List of Participants Rafael Alcaraz Barrera [email protected] IME, University of São Paulo Karam Aloui [email protected] Institut Elie Cartan de Nancy / Faculté des Sciences de Sfax Petr Ambrož petr.ambroz@fjfi.cvut.cz FNSPE, Czech Technical University in Prague Hamdi Ammar [email protected] Sfax University Myriam Amri [email protected] Sfax University Hamdi Aouinti [email protected] Université de Tunis Simon Baker [email protected] University of Reading Christoph Bandt [email protected] University of Greifswald Attila Bérczes [email protected] University of Debrecen Anne Bertrand-Mathis [email protected] University of Poitiers Dávid Bóka [email protected] Eötvös Loránd University Horst Brunotte [email protected] Marta Brzicová [email protected] FNSPE, Czech Technical University in Prague Péter Burcsi [email protected] Eötvös Loránd University Francesco Dolce [email protected] Université Paris-Est Art¯urasDubickas [email protected] Vilnius University Lubomira Dvořáková [email protected] FNSPE, Czech
    [Show full text]
  • On the Behavior of Mahler's Measure Under Iteration 1
    ON THE BEHAVIOR OF MAHLER'S MEASURE UNDER ITERATION PAUL FILI, LUKAS POTTMEYER, AND MINGMING ZHANG Abstract. For an algebraic number α we denote by M(α) the Mahler measure of α. As M(α) is again an algebraic number (indeed, an algebraic integer), M(·) is a self-map on Q, and therefore defines a dynamical system. The orbit size of α, denoted #OM (α), is the cardinality of the forward orbit of α under M. We prove that for every degree at least 3 and every non-unit norm, there exist algebraic numbers of every orbit size. We then prove that for algebraic units of degree 4, the orbit size must be 1, 2, or infinity. We also show that there exist algebraic units of larger degree with arbitrarily large but finite orbit size. 1. Introduction The Mahler measure of an algebraic number α with minimal polynomial f(x) = n anx + ··· + a0 2 Z[x] is defined as: n n Y Y M(α) = janj maxf1; jαijg = ±an αi: i=1 i=1 jαij>1 Qn where f(x) = an i=1(x − αi) 2 C[x]. It is clear that M(α) ≥ 1 is a real algebraic integer, and it follows from Kronecker's theorem that M(α) = 1 if and only if α is a root of unity. Moreover, we will freely use the facts that M(α) = M(β) whenever α and β have the same minimal polynomial, and that M(α) = M(α−1). D.H. Lehmer [10] famously asked in 1933 if the Mahler measure for an algebraic number which is not a root of unity can be arbitrarily close to 1.
    [Show full text]
  • The Smallest Perron Numbers 1
    MATHEMATICS OF COMPUTATION Volume 79, Number 272, October 2010, Pages 2387–2394 S 0025-5718(10)02345-8 Article electronically published on April 26, 2010 THE SMALLEST PERRON NUMBERS QIANG WU Abstract. A Perron number is a real algebraic integer α of degree d ≥ 2, whose conjugates are αi, such that α>max2≤i≤d |αi|. In this paper we com- pute the smallest Perron numbers of degree d ≤ 24 and verify that they all satisfy the Lind-Boyd conjecture. Moreover, the smallest Perron numbers of degree 17 and 23 give the smallest house for these degrees. The computa- tions use a family of explicit auxiliary functions. These functions depend on generalizations of the integer transfinite diameter of some compact sets in C 1. Introduction Let α be an algebraic integer of degree d, whose conjugates are α1 = α, α2,...,αd and d d−1 P = X + b1X + ···+ bd−1X + bd, its minimal polynomial. A Perron number, which was defined by Lind [LN1], is a real algebraic integer α of degree d ≥ 2 such that α > max2≤i≤d |αi|.Any Pisot number or Salem number is a Perron number. From the Perron-Frobenius theorem, if A is a nonnegative integral matrix which is aperiodic, i.e. some power of A has strictly positive entries, then its spectral radius α is a Perron number. Lind has proved the converse, that is to say, if α is a Perron number, then there is a nonnegative aperiodic integral matrix whose spectral radius is α.Lind[LN2] has investigated the arithmetic of the Perron numbers.
    [Show full text]
  • New Families of Pseudo-Anosov Homeomorphisms with Vanishing Sah-Arnoux-Fathi Invariant
    AN ABSTRACT OF THE THESIS OF Hieu Trung Do for the degree of Doctor of Philosophy in Mathematics presented on May 27, 2016. Title: New Families of pseudo-Anosov Homeomorphisms with Vanishing Sah-Arnoux-Fathi Invariant. Abstract approved: Thomas A. Schmidt Translation surfaces can be viewed as polygons with parallel and equal sides identified. An affine homeomorphism φ from a translation surface to itself is called pseudo-Anosov when its derivative is a constant matrix in SL2(R) whose trace is larger than 2 in absolute value. In this setting, the eigendirections of this matrix defines the stable and unstable flow on the translation surface. Taking a transversal to the stable flows, the first return map of the flow induces an interval exchange transformation T . The Sah-Arnoux-Fathi invariant of φ is the sum of the wedge product between the lengths of the subintervals of T and their translations. This wedge product does not depend on the choice of transversal. We apply Veech's construction of pseudo-Anosov homeomorphisms to produce infinite families of pseudo-Anosov maps in the stratum H(2; 2) with vanishing Sah-Arnoux-Fathi invariant, as well as sporadic examples in other strata. ©Copyright by Hieu Trung Do May 27, 2016 All Rights Reserved New Families of pseudo-Anosov Homeomorphisms with Vanishing Sah-Arnoux-Fathi Invariant by Hieu Trung Do A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Presented May 27, 2016 Commencement June 2016 Doctor of Philosophy thesis of Hieu Trung Do presented on May 27, 2016 APPROVED: Major Professor, representing Mathematics Chair of the Department of Mathematics Dean of the Graduate School I understand that my thesis will become part of the permanent collection of Oregon State University libraries.
    [Show full text]
  • Combinatorics, Automata and Number Theory
    Combinatorics, Automata and Number Theory CANT Edited by Val´erie Berth´e LIRMM - Univ. Montpelier II - CNRS UMR 5506 161 rue Ada, 34392 Montpellier Cedex 5, France Michel Rigo Universit´edeLi`ege, Institut de Math´ematiques Grande Traverse 12 (B 37), B-4000 Li`ege, Belgium 2 Number representation and finite automata Christiane Frougny Univ. Paris 8 and LIAFA, Univ. Paris 7 - CNRS UMR 7089 Case 7014, F-75205 Paris Cedex 13, France Jacques Sakarovitch LTCI, CNRS/ENST - UMR 5141 46, rue Barrault, F-75634 Paris Cedex 13, France. Contents 2.1 Introduction 5 2.2 Representation in integer base 8 2.2.1 Representation of integers 8 2.2.2 The evaluator and the converters 11 2.2.3 Representation of reals 18 2.2.4 Base changing 23 2.3 Representation in real base 23 2.3.1 Symbolic dynamical systems 24 2.3.2 Real base 27 2.3.3 U-systems 35 2.3.4 Base changing 43 2.4 Canonical numeration systems 48 2.4.1 Canonical numeration systems in algebraic number fields 48 2.4.2 Normalisation in canonical numeration systems 50 2.4.3 Bases for canonical numeration systems 52 2.4.4 Shift radix systems 53 2.5 Representation in rational base 55 2.5.1 Representation of integers 55 2.5.2 Representation of the reals 61 2.6 A primer on finite automata and transducers 66 2.6.1 Automata 66 2.6.2 Transducers 68 2.6.3 Synchronous transducers and relations 69 2.6.4 The left-right duality 71 3 4 Ch.
    [Show full text]
  • Ito-Sadahiro Numbers Vs. Parry Numbers
    Acta Polytechnica Vol. 51 No. 4/2011 Ito-Sadahiro numbers vs. Parry numbers Z. Mas´akov´a, E. Pelantov´a Abstract We consider a positional numeration system with a negative base, as introduced by Ito and Sadahiro. In particular, we focus on the algebraic properties of negative bases −β for which the corresponding dynamical system is sofic, which β happens, according to Ito and Sadahiro, if and only if the (−β)-expansion of − is eventually periodic. We call β +1 such numbers β Ito-Sadahiro numbers, and we compare their properties with those of Parry numbers, which occur in thesamecontextfortheR´enyi positive base numeration system. Keywords: numeration systems, negative base, Pisot number, Parry number. ∈AN 1 Introduction According to Parry, the string x1x2x3 ... rep- resents the β-expansion of a number x ∈ [0, 1) if and The expansion of a real number in the positional only if number system with base β>1, as defined by R´enyi [12] is closely related to the transformation ∗ xixi+1xi+2 ...≺ d (1) (2) T :[0, 1) → [0, 1), given by the prescription T (x):= β βx −#βx$.Everyx ∈ [0, 1) is a sum of the infinite for every i =1, 2, 3,... series D { | ∞ Condition (2) ensures that the set β = dβ(x) xi − ∈ } D x = , where x = #βT i 1(x)$ (1) x [0, 1) is shift invariant, and so the closure of β βi i N i=1 in A , denoted by Sβ, is a subshift of the full shift N for i =1, 2, 3,... A . The notion of β-expansion can naturally be ex- Directly from the definition of the transformation T tended to all non-negative real numbers: The expres- we can derive that the ‘digits’ x take values in the set i sion of a positive real number y in the form {0, 1, 2,...,%β&−1} for i =1, 2, 3,...
    [Show full text]
  • On the Dichotomy of Perron Numbers and Beta-Conjugates Jean-Louis Verger-Gaugry
    On the dichotomy of Perron numbers and beta-conjugates Jean-Louis Verger-Gaugry To cite this version: Jean-Louis Verger-Gaugry. On the dichotomy of Perron numbers and beta-conjugates. Monatshefte für Mathematik, Springer Verlag, 2008, 155, pp.277-299. 10.1007/s00605-008-0002-1. hal-00338280 HAL Id: hal-00338280 https://hal.archives-ouvertes.fr/hal-00338280 Submitted on 12 Nov 2008 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. On the dichotomy of Perron numbers and beta-conjugates Jean-Louis Verger-Gaugry ∗ Abstract. Let β > 1 be an algebraic number. A general definition of a beta-conjugate i of β is proposed with respect to the analytical function fβ(z) = −1+ Pi≥1 tiz associated with the R´enyi β-expansion dβ(1) = 0.t1t2 . of unity. From Szeg¨o’s Theorem, we study the dichotomy problem for fβ(z), in particular for β a Perron number: whether it is a rational fraction or admits the unit circle as natural boundary. The first case of dichotomy meets Boyd’s works. We introduce the study of the geometry of the beta-conjugates with respect to that of the Galois conjugates by means of the Erd˝os-Tur´an approach and take examples of Pisot, Salem and Perron numbers which are Parry numbers to illustrate it.
    [Show full text]
  • Special Classes of Algebraic Integers in Low-Dimensional Topology
    Special classes of algebraic integers in low-dimensional topology Eriko Hironaka April 15, 2005 Abstract This note describes some open problems concerning distributions of special classes of real algebraic integers such as algebraic units, and Salem, P-V and Perron numbers. These special algebraic integers appear naturally as geometric invariants in low-dimensional topology. We relate properties of Salem, P-V and Perron to minimization problems in various geometric settings. 1 Introduction A complex number α ∈ C is an algebraic integer if it is a root of a monic integer polynomial. Two algebraic integers α and β are algebraically conjugate, written α ∼ β, if α and β satisfy the same irreducible monic integer polynomial. An algebraic integer α is an algebraic unit if α ∼ α−1. Let α be a real algebraic integer with α > 1. Consider all β ∼ α such that β 6= α: (i) if |β| < |α|, then α is a Perron number; (ii) if |β| < 1, then α is a P-V number; and (iii) if |β| ≤ 1 with at least one |β| = 1, then α is a Salem number. In this short note, we review definitions and known results concerning distributions of P-V, Salem and Perron numbers (Section 2), and relate them to geometric invariants in low-dimensional topology, including lengths of geodesics, growth rates of automatic groups, and homological and geometric dilatations of surface homeomorphisms (Section 3). 2 Distributions of algebraic integers and Lehmer’s problem Let P be the set of monic integer polynomials. Given f ∈ P, let Sf be the set of complex roots of + f counted with multiplicity, and let S (f) ⊂ Sf be the subset of points outside the unit circle C.
    [Show full text]
  • A Proof of the Conjecture of Lehmer
    A PROOF OF THE CONJECTURE OF LEHMER AND OF THE CONJECTURE OF SCHINZEL-ZASSENHAUS JEAN-LOUIS VERGER-GAUGRY September 13, 2017 Abstract. The conjecture of Lehmer is proved to be true. The proof mainly relies upon: (i) the properties of the Parry Upper functions f α (z) associated with the dynamical zeta functions ζ α (z) of the Rényi–Parry arithmetical dynamical systems, for α an algebraic integer α of house α greater than 1, (ii) the discovery of lenticuli of poles of ζ α (z) which uniformly equidistribute at the limit on a limit “lenticular" arc of the unit circle, when α tends to 1+, giving rise to a contin- uous lenticular minorant Mr( α ) of the Mahler measure M(α), (iii) the Poincaré asymptotic expansions of these poles and of this minorant Mr( α ) as a function of the dynamical degree. With the same arguments the conjecture of Schinzel- Zassenhaus is proved to be true. An inequality improving those of Dobrowolski and Voutier ones is obtained. The set of Salem numbers is shown to be bounded −1 from below by the Perron number θ31 =1.08545 ..., dominant root of the trinomial 1 z30 + z31. Whether Lehmer’s number is the smallest Salem number remains open.− − A lower bound for the Weil height of nonzero totally real algebraic num- bers, = 1, is obtained (Bogomolov property). For sequences of algebraic integers of Mahler6 ± measure smaller than the smallest Pisot number, whose houses have a dynamical degree tending to infinity, the Galois orbit measures of conjugates are proved to converge towards the Haar measure on z =1 (limit equidistribution).
    [Show full text]
  • Simultaneous Observability of Infinitely Many Strings and Beams
    NETWORKS AND HETEROGENEOUS MEDIA doi:10.3934/nhm.2020017 c American Institute of Mathematical Sciences Volume 15, Number 4, December 2020 pp. 633{652 SIMULTANEOUS OBSERVABILITY OF INFINITELY MANY STRINGS AND BEAMS Vilmos Komornik College of Mathematics and Computational Science Shenzhen University Shenzhen 518060, Peoples Republic of China Dpartement de mathmatique Universit de Strasbourg 7 rue Ren Descartes 67084 Strasbourg Cedex, France Anna Chiara Lai and Paola Loreti∗ Sapienza Universit di Roma Dipartimento di Scienze di Base e Applicate per l'Ingegneria Via A. Scarpa, 16 00161, Roma, Italy (Communicated by Enrique Zuazua) Abstract. We investigate the simultaneous observability of infinite systems of vibrating strings or beams having a common endpoint where the observation is taking place. Our results are new even for finite systems because we allow the vibrations to take place in independent directions. Our main tool is a vectorial generalization of some classical theorems of Ingham, Beurling and Kahane in nonharmonic analysis. 1. Introduction. In this paper we are investigating finite and infinite systems of strings or beams having a common endpoint, whose transversal vibrations may take place in different planes. We are interested in conditions ensuring their simultaneous observability and in estimating the sufficient observability time. There have been many results during the last twenty years on the simultaneous observability and controllability of systems of strings and beams, see e.g., [1]-[6], [11]-[12], [20], [25]. In all earlier papers the vibrations were assumed to take place in a common vertical plane. Here, we still assume that each string or beam is vibrating in some plane, but these planes may differ from one another.
    [Show full text]
  • Uniform Distribution Theory 3 (2008), No.2, 157–190 Distribution Theory
    uniform Uniform Distribution Theory 3 (2008), no.2, 157{190 distribution theory UNIFORM DISTRIBUTION OF GALOIS CONJUGATES AND BETA-CONJUGATES OF A PARRY NUMBER NEAR THE UNIT CIRCLE AND DICHOTOMY OF PERRON NUMBERS Jean-Louis Verger-Gaugry ABSTRACT. Concentration and equi-distribution, near the unit circle, in Solo- myak's set, of the union of the Galois conjugates and the beta-conjugates of a Parry number ¯ are characterized by means of the Erd}os-Tur¶anapproach, and its improvements by Mignotte and Amoroso, applied to the analytical function P i f¯ (z) = ¡1 + i¸1 tiz associated with the R¶enyi ¯-expansion d¯ (1) = 0:t1t2 ::: of unity. Mignotte's discrepancy function requires the knowledge of the factor- ization of the Parry polynomial of ¯. This one is investigated using theorems of Cassels, Dobrowolski, Pinner and Vaaler, Smyth, Schinzel in terms of cyclo- tomic, reciprocal non-cyclotomic and non-reciprocal factors. An upper bound of Mignotte's discrepancy function which arises from the beta-conjugates of ¯ which are roots of cyclotomic factors is linked to the Riemann hypothesis, following Amoroso. An equidistribution limit theorem, following Bilu's theorem, is formu- lated for the concentration phenomenon of conjugates of Parry numbers near the unit circle. Parry numbers are Perron numbers. Open problems on non-Parry Perron numbers are mentioned in the context of the existence of non-unique fac- torizations of elements of number ¯elds into irreducible Perron numbers (Lind). Communicated by Ilya Shkredov Contents 1. Introduction 158 2. Szeg}o'sTheorem and numeration 160 3. Parry polynomials, Galois- and beta-conjugates in Solomyak's set ­ for a Parry number ¯ 161 2000 M a t h e m a t i c s S u b j e c t C l a s s i f i c a t i o n: 11M99, 30B10, 12Y05.
    [Show full text]
  • On the Behavior of Mahler's Measure Under Iteration
    Monatshefte für Mathematik (2020) 193:61–86 https://doi.org/10.1007/s00605-020-01416-5 On the behavior of Mahler’s measure under iteration Paul A. Fili1 · Lukas Pottmeyer2 · Mingming Zhang1 Received: 21 November 2019 / Accepted: 9 April 2020 / Published online: 20 April 2020 © The Author(s) 2020 Abstract For an algebraic number α we denote by M(α) the Mahler measure of α.AsM(α) is again an algebraic number (indeed, an algebraic integer), M(·) is a self-map on Q, and therefore defines a dynamical system. The orbit size of α, denoted #OM (α),is the cardinality of the forward orbit of α under M. We prove that for every degree at least 3 and every non-unit norm, there exist algebraic numbers of every orbit size. We then prove that for algebraic units of degree 4, the orbit size must be 1, 2, or infinity. We also show that there exist algebraic units of larger degree with arbitrarily large but finite orbit size. Keywords Mahler measure · Lehmer’s problem · Algebraic numbers Mathematics Subject Classification 11R06 · 11R04 · 11R09 1 Introduction The Mahler measure of an algebraic number α with minimal polynomial f (x) = n an x +···+a0 ∈ Z[x], is defined as: Communicated by H. Bruin. B Lukas Pottmeyer [email protected] Paul A. Fili paul.fi[email protected] Mingming Zhang [email protected] 1 Oklahoma State University, Stillwater, OK 74078, USA 2 Universität Duisberg-Essen, 45117 Essen, Germany 123 62 P. A. Fili et al. n n M(α) =|an| max{1, |αi |} = ±an αi , i=1 i=1 |αi |>1 α ,...,α ( ) ( ) = n ( − α ) ∈ C[ ] where 1 n are the distinct roots of f x ; i.e.
    [Show full text]