13 research outputs found
Zeros of polynomials orthogonal with respect to a signed weight
AbstractIn this paper we consider the monic polynomial sequence (Pnα,q(x)) that is orthogonal on [â1,1] with respect to the weight function x2q+1(1âx2)α(1âx),α>â1,qâN; we obtain the coefficients of the tree-term recurrence relation(TTRR) by using a different method from the one derived in Atia et al. (2002) [2]; we prove that the interlacing property does not hold properly for (Pnα,q(x)); and we also prove that, if xn,nα+i,q+j is the largest zero of Pnα+i,q+j(x), x2nâ2j,2nâ2jα+j,q+j<x2nâ2i,2nâ2iα+i,q+i,0â€i<jâ€nâ1
A Survey on q-Polynomials and their Orthogonality Properties
In this paper we study the orthogonality conditions satisfied by the
classical q-orthogonal polynomials that are located at the top of the q-Hahn
tableau (big q-jacobi polynomials (bqJ)) and the Nikiforov-Uvarov tableau
(Askey-Wilson polynomials (AW)) for almost any complex value of the parameters
and for all non-negative integers degrees. We state the degenerate version of
Favard's theorem, which is one of the keys of the paper, that allow us to
extend the orthogonality properties valid up to some integer degree N to
Sobolev type orthogonality properties. We also present, following an analogous
process that applied in [16], tables with the factorization and the discrete
Sobolev-type orthogonality property for those families which satisfy a finite
orthogonality property, i.e. it consists in sum of finite number of masspoints,
such as q-Racah (qR), q-Hahn (qH), dual q-Hahn (dqH), and q-Krawtchouk
polynomials (qK), among others.
-- [16] R. S. Costas-Santos and J. F. Sanchez-Lara. Extensions of discrete
classical orthogonal polynomials beyond the orthogonality. J. Comp. Appl.
Math., 225(2) (2009), 440-451Comment: 3 Figures, 3 tables, in a 22 pages manuscrip
The semiclassical--Sobolev orthogonal polynomials: a general approach
We say that the polynomial sequence is a semiclassical
Sobolev polynomial sequence when it is orthogonal with respect to the inner
product where is a semiclassical linear functional,
is the differential, the difference or the --difference
operator, and is a positive constant. In this paper we get algebraic
and differential/difference properties for such polynomials as well as
algebraic relations between them and the polynomial sequence orthogonal with
respect to the semiclassical functional . The main goal of this article
is to give a general approach to the study of the polynomials orthogonal with
respect to the above nonstandard inner product regardless of the type of
operator considered. Finally, we illustrate our results by
applying them to some known families of Sobolev orthogonal polynomials as well
as to some new ones introduced in this paper for the first time.Comment: 23 pages, special issue dedicated to Professor Guillermo Lopez
lagomasino on the occasion of his 60th birthday, accepted in Journal of
Approximation Theor
Extensions of discrete classical orthogonal polynomials beyond the orthogonality
It is well known that the family of Hahn polynomials
is orthogonal with respect to a certain
weight function up to . In this paper we present a factorization for Hahn
polynomials for a degree higher than and we prove that these polynomials
can be characterized by a -Sobolev orthogonality.
We also present an analogous result for dual-Hahn, Krawtchouk, and Racah
polynomials and give the limit relations between them for all n\in \XX N_0.
Furthermore, in order to get this results for the Krawtchouk polynomials we
will get a more general property of orthogonality for Meixner polynomials.Comment: 2 figures, 20 page
Limit relations between -Krall type orthogonal polynomials
In this paper, we consider a natural extension of several results related to
Krall-type polynomials introducing a modification of a -classical linear
functional via the addition of one or two mass points. The limit relations
between the -Krall type modification of big -Jacobi, little -Jacobi,
big -Laguerre, and other families of the -Hahn tableau are established.Comment: 19 Pages, 3 tables, 1 figur
The Hahn Quantum Variational Calculus
We introduce the Hahn quantum variational calculus. Necessary and sufficient
optimality conditions for the basic, isoperimetric, and Hahn quantum Lagrange
problems, are studied. We also show the validity of Leitmann's direct method
for the Hahn quantum variational calculus, and give explicit solutions to some
concrete problems. To illustrate the results, we provide several examples and
discuss a quantum version of the well known Ramsey model of economics.Comment: Submitted: 3/March/2010; 4th revision: 9/June/2010; accepted:
18/June/2010; for publication in Journal of Optimization Theory and
Application
Disponibilidade e qualidade do capim-elefante com e sem irrigação adubado com nitrogĂȘnio e potĂĄssio na estação seca Forage yield and quality of elephantgrass response to irrigation and nitrogen and potassium fertilization in the dry season
Objetivou-se com este trabalho avaliar os efeitos da irrigação e da adubação com N e K sobre a disponibilidade e a qualidade da matĂ©ria seca em pastagem de capim-elefante cv. Napier adubada com N e K nas dosagens de 100:80; 200:160; 300:240 e 400:320 kg.ha-1.ano-1 de N e K2O, respectivamente, no perĂodo seco do ano. Foram conduzidos dois experimentos (ĂĄrea irrigada - AI e nĂŁo-irrigada - ANI), segundo delineamento de blocos casualizados com trĂȘs repetiçÔes, em que a unidade experimental consistiu de parcelas (piquetes) de 300 mÂČ, nas quais foram aplicados os tratamentos. No perĂodo de avaliação (maio a setembro/2001 - perĂodo seco), as disponibilidades de matĂ©ria seca total (DMST) e lĂąmina foliar (DMSLF) apresentaram valores proporcionais Ă s doses de nitrogĂȘnio e potĂĄssio. A irrigação teve efeito significativo sobre a DMSLF. No entanto, os teores de FDN e FDA, ao longo do perĂodo seco, na ĂĄrea nĂŁo-irrigada foram menores que na ĂĄrea irrigada. As concentraçÔes de PB e dos macrominerais (P, K, Ca e Mg) nĂŁo foram influenciadas pelas doses de N e K e pela irrigação, tanto na ĂĄrea irrigada como na nĂŁo-irrigada.<br>An experiment was carried out in experimental plots of 300 mÂČ in size to evaluate the effects of doses of NK fertilization and irrigation on forage mass yield and quality of elephantgras cv Napier during the dry season. The experimental design was completely randomized with three treatment replications. The experimental treatments were arranged in a 4 x 2 factorial combination of four N-K2O doses with and without irrigation, in the dry season. N-K2O doses were: 100-80; 200-160; 300-240 and 400-320 kg.ha-1, respectively. Figures for total dry forage mass (TDFM), and dry green leaf mass (DGLM) increased in proportion to N-K2O dose from May to September 2001, the dry season period. Irrigation had a marked significant effect on DGLM yield. Leaf samples from irrigated plots had higher contents of neutral and acid detergent fiber as compared to leaf samples from the control plots. Concentrations of crude protein, potash, phosphorus, calcium and magnesium did not respond either to N-K2O doses or to irrigation