Displaying similar documents to “On the length of rational continued fractions over q ( X )

Automatic continued fractions are transcendental or quadratic

Yann Bugeaud (2013)

Annales scientifiques de l'École Normale Supérieure

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We establish new combinatorial transcendence criteria for continued fraction expansions. Let  α = [ 0 ; a 1 , a 2 , ... ] be an algebraic number of degree at least three. One of our criteria implies that the sequence of partial quotients ( a ) 1 of  α is not ‘too simple’ (in a suitable sense) and cannot be generated by a finite automaton.

Lacunary formal power series and the Stern-Brocot sequence

Jean-Paul Allouche, Michel Mendès France (2013)

Acta Arithmetica

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Let F ( X ) = n 0 ( - 1 ) ε X - λ be a real lacunary formal power series, where εₙ = 0,1 and λ n + 1 / λ > 2 . It is known that the denominators Qₙ(X) of the convergents of its continued fraction expansion are polynomials with coefficients 0, ±1, and that the number of nonzero terms in Qₙ(X) is the nth term of the Stern-Brocot sequence. We show that replacing the index n by any 2-adic integer ω makes sense. We prove that Q ω ( X ) is a polynomial if and only if ω ∈ ℤ. In all the other cases Q ω ( X ) is an infinite formal power series; we discuss...

Pell and Pell-Lucas numbers of the form - 2 a - 3 b + 5 c

Yunyun Qu, Jiwen Zeng (2020)

Czechoslovak Mathematical Journal

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In this paper, we find all Pell and Pell-Lucas numbers written in the form - 2 a - 3 b + 5 c , in nonnegative integers a , b , c , with 0 max { a , b } c .

Multidimensional Gauss reduction theory for conjugacy classes of SL ( n , )

Oleg Karpenkov (2013)

Journal de Théorie des Nombres de Bordeaux

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In this paper we describe the set of conjugacy classes in the group SL ( n , ) . We expand geometric Gauss Reduction Theory that solves the problem for SL ( 2 , ) to the multidimensional case, where ς -reduced Hessenberg matrices play the role of reduced matrices. Further we find complete invariants of conjugacy classes in GL ( n , ) in terms of multidimensional Klein-Voronoi continued fractions.

5-dissections and sign patterns of Ramanujan's parameter and its companion

Shane Chern, Dazhao Tang (2021)

Czechoslovak Mathematical Journal

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In 1998, Michael Hirschhorn discovered the 5-dissection formulas of the Rogers-Ramanujan continued fraction R ( q ) and its reciprocal. We obtain the 5-dissections for functions R ( q ) R ( q 2 ) 2 and R ( q ) 2 / R ( q 2 ) , which are essentially Ramanujan’s parameter and its companion. Additionally, 5-dissections of the reciprocals of these two functions are derived. These 5-dissection formulas imply that the coefficients in their series expansions have periodic sign patterns with few exceptions.

An approximation property of quadratic irrationals

Takao Komatsu (2002)

Bulletin de la Société Mathématique de France

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Let α > 1 be irrational. Several authors studied the numbers m ( α ) = inf { | y | : y Λ m , y 0 } , where m is a positive integer and Λ m denotes the set of all real numbers of the form y = ϵ 0 α n + ϵ 1 α n - 1 + + ϵ n - 1 α + ϵ n with restricted integer coefficients | ϵ i | m . The value of 1 ( α ) was determined for many particular Pisot numbers and m ( α ) for the golden number. In this paper the value of  m ( α ) is determined for irrational numbers  α , satisfying α 2 = a α ± 1 with a positive integer a .

The growth speed of digits in infinite iterated function systems

Chun-Yun Cao, Bao-Wei Wang, Jun Wu (2013)

Studia Mathematica

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Let f n 1 be an infinite iterated function system on [0,1] satisfying the open set condition with the open set (0,1) and let Λ be its attractor. Then to any x ∈ Λ (except at most countably many points) corresponds a unique sequence a ( x ) n 1 of integers, called the digit sequence of x, such that x = l i m n f a ( x ) f a ( x ) ( 1 ) . We investigate the growth speed of the digits in a general infinite iterated function system. More precisely, we determine the dimension of the set x Λ : a ( x ) B ( n 1 ) , l i m n a ( x ) = for any infinite subset B ⊂ ℕ, a question posed by...

Perfect unary forms over real quadratic fields

Dan Yasaki (2013)

Journal de Théorie des Nombres de Bordeaux

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Let F = ( d ) be a real quadratic field with ring of integers 𝒪 . In this paper we analyze the number h d of GL 1 ( 𝒪 ) -orbits of homothety classes of perfect unary forms over F as a function of d . We compute h d exactly for square-free d 200000 . By relating perfect forms to continued fractions, we give bounds on h d and address some questions raised by Watanabe, Yano, and Hayashi.

Fermat k -Fibonacci and k -Lucas numbers

Jhon J. Bravo, Jose L. Herrera (2020)

Mathematica Bohemica

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Using the lower bound of linear forms in logarithms of Matveev and the theory of continued fractions by means of a variation of a result of Dujella and Pethő, we find all k -Fibonacci and k -Lucas numbers which are Fermat numbers. Some more general results are given.

Estimates of L p norms for sums of positive functions

Ilgiz Kayumov (2013)

Annales Universitatis Mariae Curie-Sklodowska, sectio A – Mathematica

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We present new inequalities of L p norms for sums of positive functions. These inequalities are useful for investigation of convergence of simple partial fractions in L p ( ) .

On the unit group of a semisimple group algebra 𝔽 q S L ( 2 , 5 )

Rajendra K. Sharma, Gaurav Mittal (2022)

Mathematica Bohemica

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We give the characterization of the unit group of 𝔽 q S L ( 2 , 5 ) , where 𝔽 q is a finite field with q = p k elements for prime p > 5 , and S L ( 2 , 5 ) denotes the special linear group of 2 × 2 matrices having determinant 1 over the cyclic group 5 .

On sums and products in a field

Guang-Liang Zhou, Zhi-Wei Sun (2022)

Czechoslovak Mathematical Journal

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We study sums and products in a field. Let F be a field with ch ( F ) 2 , where ch ( F ) is the characteristic of F . For any integer k 4 , we show that any x F can be written as a 1 + + a k with a 1 , , a k F and a 1 a k = 1 , and that for any α F { 0 } we can write every x F as a 1 a k with a 1 , , a k F and a 1 + + a k = α . We also prove that for any x F and k { 2 , 3 , } there are a 1 , , a 2 k F such that a 1 + + a 2 k = x = a 1 a 2 k .

Repdigits in generalized Pell sequences

Jhon J. Bravo, Jose L. Herrera (2020)

Archivum Mathematicum

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For an integer k 2 , let ( n ) n be the k - generalized Pell sequence which starts with 0 , ... , 0 , 1 ( k terms) and each term afterwards is given by the linear recurrence n = 2 n - 1 + n - 2 + + n - k . In this paper, we find all k -generalized Pell numbers with only one distinct digit (the so-called repdigits). Some interesting estimations involving generalized Pell numbers, that we believe are of independent interest, are also deduced. This paper continues a previous work that searched for repdigits in the usual Pell sequence ( P n ( 2 ) ) n . ...

Approximation properties of β-expansions

Simon Baker (2015)

Acta Arithmetica

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Let β ∈ (1,2) and x ∈ [0,1/(β-1)]. We call a sequence ( ϵ i ) i = 1 0 , 1 a β-expansion for x if x = i = 1 ϵ i β - i . We call a finite sequence ( ϵ i ) i = 1 n 0 , 1 n an n-prefix for x if it can be extended to form a β-expansion of x. In this paper we study how good an approximation is provided by the set of n-prefixes. Given Ψ : 0 , we introduce the following subset of ℝ: W β ( Ψ ) : = m = 1 n = m ( ϵ i ) i = 1 n 0 , 1 n [ i = 1 n ( ϵ i ) / ( β i ) , i = 1 n ( ϵ i ) / ( β i ) + Ψ ( n ) ] In other words, W β ( Ψ ) is the set of x ∈ ℝ for which there exist infinitely many solutions to the inequalities 0 x - i = 1 n ( ϵ i ) / ( β i ) Ψ ( n ) . When n = 1 2 n Ψ ( n ) < , the Borel-Cantelli lemma tells us that the Lebesgue measure...