Abstract not found

We present a survey of the recent applications of continuous domains for providing simple computational models for classical spaces in mathematics including the real line, countably based locally compact spaces, complete separable metric spaces, separable Banach spaces and spaces of probability distributions. It is shown how these models have a logical and effective presentation and how they are used to give a computational framework in several areas in mathematics and physics. These include fractal geometry, where new results on existence and uniqueness of attractors and invariant distributions have been obtained, measure and integration theory, where a generalization of the Riemann theory of integration has been developed, and real arithmetic, where a feasible setting for exact computer arithmetic has been formulated. We give a number of algorithms for computation in the theory of iterated function systems with applications in statistical physics and in period doubling route to chao...

Abstract. Explicit solutions for the three-term recurrence satisfied by associated continuous dual q-Hahn polynomials are obtained. A minimal solution is identified and an explicit expression for the related continued fraction is derived. The absolutely continuous component of the spectral measure is obtained. Eleven limit cases are discussed in some detail. These include associated big q-Laguerre, associated Wall, associated Al-Salam-Chihara, associated Al-Salam-Carlitz I, and associated continuous q-Hermite polynomials.

. First, several algorithms based on the unsymmetric Lanczos process are surveyed: the biorthogonalization (BO) algorithm for constructing a tridiagonal matrix T similar to a given matrix A (whose extreme spectrum is sought typically); the "BOBC algorithm", which generates directly the LU factors of T ; the Biores (Lanczos/Orthores), Biomin (Lanczos/Orthomin or biconjugate gradient (BCG)), and the Biodir (Lanczos/Orthodir) algorithms for solving a nonsymmetric system of linear equations. The possibilities of breakdown in these algorithms are discussed and brought into relation. Then the connections to formal orthogonal polynomials, Pad'e approximation, continued fractions, and the qd algorithm are reviewed. They allow us to deapen our understanding of breakdowns. Next, three types of (bi)conjugate gradient squared (CGS) algorithms are presented: Biores 2 , Biomin 2 (standard CGS), and Biodir 2 . Finally, fast Hankel solvers related to the Lanczos process are described. 1 Key ...

Applying Zeilberger's algorithm of creative telescoping to a family of certain very-well-poised hypergeometric series involving linear forms in Catalan's constant with rational coefficients, we obtain a second-order difference equation for these forms and their coefficients. As a consequence we derive a new way of fast calculation of Catalan's constant as well as a new continued-fraction expansion for it. Similar arguments are put forward to deduce a second-order difference equation and a new continued fraction for ζ(4) = π^4/90.

The Berlekamp-Massey algorithm takes a sequence of elements from a field and finds the shortest linear recurrence (or linear feedback shift register) that can generate the sequence. In this paper we extend the algorithm to the case when the elements of the sequence are integers modulo m, where m is an arbitrary integer with known prime decomposition.

It is explained how the classical concept of well-poised hypergeometric series and integrals becomes crucial in studing arithmetic properties of the values of Riemann’s zeta function. By these well-poised means we obtain: (1) a permutation group for linear forms in 1 and ζ(4) = π 4 /90 yielding a conditional upper bound for the irrationality measure of ζ(4); (2) a second-order Apéry-like recursion for ζ(4) and some low-order recursions for linear forms in odd zeta values; (3) a rich permutation group for a family of certain Euler-type multiple integrals that generalize so-called Beukers’ integrals for ζ(2) and ζ(3).

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: Classic works of Karlin-McGregor and Jones-Magnus have established a general correspondence between continuous-time birth-and-death processes and continued fractions of the Stieltjes-Jacobi type together with their associated orthogonal polynomials. This fundamental correspondence is revisited here in the light of the basic relation between weighted lattice paths and continued fractions otherwise known from combinatorial theory. Given that trajectories of the embedded Markovchain of a birth-and-death process are lattice paths, Laplace transforms of a number of transientcharacteristics can be obtained systematically in terms of a fundamental continued fraction and its family of convergent polynomials. Applications include the analysis of evolutions in a strip, upcrossing and downcrossing times under #ooring and ceiling conditions, as well as time, area, or n umber of transitions while a geometric condition is satis#ed. Key-words: Lattice path combinatorics, continued fractions, ortho...

Abstract. We study nonsymmetric tridiagonal operators acting in the Hilbert space ℓ 2 and describe the spectrum and the resolvent set of such operators in terms of a continued fraction related to the resolvent. In this way we establish a connection between Padé approximants and spectral properties of nonsymmetric tridiagonal operators. 1.