Invariance Principles in Metric Diophantine Approximation

In [7], LeVeque proved a central limit theorem for the number of solutions p,q of

Approximation Properties of Two-Dimensional Continued Fractions

By using the difference formula for approximations of two-dimensional continued fractions, the method of fundamental inequalities, the Stieltjes–Vitali theorem, and generalizations of divided and inverse differences, we estimate the accuracy of approximations of two-dimensional continued fractions with complex elements by their convergents and obtain estimates for the real and imaginary parts of remainders of two-dimensional continued fractions. We also prove an analog of the van Vleck theorem and construct an interpolation formula of the Newton–Thiele type.     

一类连分数的有理逼近

设f(n)是非负函数,k,b,s_i,t_i(i=1,2,…)是正常数,研究形如[a_0,a_1,a_2…]=[■]_m~∞=0和[■]_n~∞=1的连分数有理逼近的下界．     

On Metric Diophantine Approximation in the Field of Formal Laurent Series

B. deMathan (1970, Bull. Soc. Math. France Supl. Mem.21) proved that Khintchine’s Theorem has an analogue in the field of formal Laurent series. First, we show that in case of only one inequality this result can also be obtained by continued fraction theory. Then, we are interested in the number of solutions and show under special assumptions that one gets a central limit theorem, a law of iterated logarithm and an asymptotic formula. This is an analogue of a result due to W. J. LeVeque (1958, Trans. Amer. Math. Soc.87, 237–260). The proof is based on probabilistic results for formal Laurent series due to H. Niederreiter (1988, in Lecture Notes in Computer Science, Vol. 330, pp. 191–209, Springer-Verlag, New York/Berlin).     

Matrix Continued Fractions

A matrix continued fraction is defined and used for the approximation of a function known as a power series in 1/zwith matrix coefficientsp×q, or equivalently by a matrix of functions holomorphic at infinity. It is a generalization of P-fractions, and the sequence of convergents converges to the given function. These convergents have as denominators a matrix, the columns of which are orthogonal with respect to the linear matrix functional associated to . The case where the algorithm breaks off is characterized in terms of .     

Hurwitz and Tasoev Continued Fractions

The continued fractions studied by Tasoev are not widely known although their characteristics are very similar to those of Hurwitz continued fractions. Recently, the author found several general forms of Tasoev continued fractions, and by applying this method he also obtained some more general forms of Hurwitz continued fractions belonging to so called tanh-type and tan-type. In this paper, we constitute a new class of general forms of Hurwitz continued fractions of e-type. The known continued fraction expansions of e^1/a (a 1), ae^1/a and (1/a)e^1/a are included as special cases. The corresponding Tasoev continued fractions are also derived.     

Hurwitz and Tasoev Continued Fractions

The continued fractions studied by Tasoev are not widely known although their characteristics are very similar to those of Hurwitz continued fractions. Recently, the author found several general forms of Tasoev continued fractions, and by applying this method he also obtained some more general forms of Hurwitz continued fractions belonging to so called tanh-type and tan-type. In this paper, we constitute a new class of general forms of Hurwitz continued fractions of e-type. The known continued fraction expansions of e^1/a (a 1), ae^1/a and (1/a)e^1/a are included as special cases. The corresponding Tasoev continued fractions are also derived.     

Additive Partitions and Continued Fractions

A set S of positive integers is avoidable if there exists a partition of the positive integers into two disjoint sets such that no two distinct integers from the same set sum to an element of S. Much previous work has focused on proving the avoidability of very special sets of integers. We vastly broaden the class of avoidable sets by establishing a previously unnoticed connection with the elementary theory of continued fractions.     

Palindromic Prefixes and Diophantine Approximation

This article is devoted to simultaneous approximation to ξ and ξ² by rational numbers with the same denominator, where ξ is an irrational non-quadratic real number. We focus on an exponent β₀(ξ) that measures the regularity of the sequence of all exceptionally precise such approximants. We prove that β₀(ξ) takes the same set of values as a combinatorial quantity that measures the abundance of palindromic prefixes in an infinite word w. This allows us to give a precise exposition of Roy’s palindromic prefix method. The main tools we use are Davenport-Schmidt’s sequence of minimal points and Roy’s bracket operation.     

Interpolational Integral Continued Fractions

For nonlinear functionals defined on the space of piecewise-continuous functions, we construct an interpolational integral continued fraction on continual piecewise-continuous nodes and establish conditions for the existence and uniqueness of interpolants of this type.     

连分式的不等式

本文研究二元连分式G(m,λ)的单调性质,得到一些新的连分式不等式．     

Quasi-Elliptic Integrals and Periodic Continued Fractions

 In this report we detail the following story. Several centuries ago, Abel noticed that the well-known elementary integral

Nonhomogeneous recursions and Generalised Continued Fractions

Consider the (n+1)st order nonhomogeneous recursionX _k+n+1=b _k X _k+n +a _k ⁽ⁿ⁾ X _k+n-1+...+a _k ⁽¹⁾ X _k +X _k .Leth be a particular solution, andf ⁽¹⁾,...,f ⁽ⁿ⁾,g independent solutions of the associated homogeneous equation. It is supposed thatg dominatesf ⁽¹⁾,...,f ⁽ⁿ⁾ andh. If we want to calculate a solutiony which is dominated byg, but dominatesf ⁽¹⁾,...,f ⁽ⁿ⁾, then forward and backward recursion are numerically unstable. A stable algorithm is derived if we use results constituting a link between Generalised Continued Fractions and Recursion Relations.     

Continued Fractions and Unique Additive Partitions

A partition of the positive integers into sets A and B avoids a set S N if no two distinct elements in the same part have a sum in S. If the partition is unique, S is uniquely avoidable. For any irrational > 1, Chow and Long constructed a partition which avoids the numerators of all convergents of the continued fraction for , and conjectured that the set S which this partition avoids is uniquely avoidable. We prove that the set of numerators of convergents is uniquely avoidable if and only if the continued fraction for has infinitely many partial quotients equal to 1. We also construct the set S and show that it is always uniquely avoidable.     

有限Diophantine逼近与Fibonacci多项式

设x为一无理数具简单的连分式展开x = [a0, a1, a2,…, an].若对无穷多个是标k有ak> n则至少有m个解p/q(p与q互素)使不等式 x - p/q 相似文献   

Approximation by Simplest Fractions

In this paper, a number of problems concerning the uniform approximation of complex-valued continuous functions on compact subsets of the complex plane by simplest fractions of the form are considered. In particular, it is shown that the best approximation of a function by the fractions is of the same order of vanishing as the best approximations by polynomials of degree .     

Approximation of Metric Spaces by Partial Metric Spaces

Partial metrics are generalised metrics with non-zero self-distances. We slightly generalise Matthews' original definition of partial metrics, yielding a notion of weak partial metric. After considering weak partial metric spaces in general, we introduce a weak partial metric on the poset of formal balls of a metric space. This weak partial metric can be used to construct the completion of classical metric spaces from the domain-theoretic rounded ideal completion.     

Hausdorff Dimension and Generalized Simultaneous Diophantine Approximation

Suppose that m is a positive integer, is a vector of strictly positive numbers, and Qis an infinite set of positive integers. Let W_Q(m; ) be theset [formula] In this paper we obtain the Hausdorff dimension of this set.We also consider a generalization of the set W_Q(m; ), wherethe error terms in the inequalities are replaced by _i(q), for general functions _i satisfying a certaincondition at infinity. 1991 Mathematics Subject Classification11J83, 28A78.