On Vladimir Markov type inequality in Lp norms on the interval [-1; 1]

2019 ◽  
Vol 7 (4) ◽  
pp. 9-12
Author(s):  
Mirosław Baran ◽  
Paweł Ozorka

We prove inequality ||P(k)||Lp(-1;1)≤Bp||Tn(k)||Lp(-1;1)n^(2/p) ||P||Lp(-1;1); where Bp are constants independent of n = deg P with 1 ≤ p ≤ 2, which is sharp in the case k ≥ 3. A method presented in this note is based on a factorization of linear operator of k-th derivative throughout normed spaces of polynomial equipped with a Wiener type norm.

2020 ◽  
pp. 1950022
Author(s):  
Francisco Marcellán ◽  
José M. Rodríguez

Weighted Sobolev spaces play a main role in the study of Sobolev orthogonal polynomials. In particular, analytic properties of such polynomials have been extensively studied, mainly focused on their asymptotic behavior and the location of their zeros. On the other hand, the behavior of the Fourier–Sobolev projector allows to deal with very interesting approximation problems. The aim of this paper is twofold. First, we improve a well-known inequality by Lupaş by using connection formulas for Jacobi polynomials with different parameters. In the next step, we deduce Markov-type inequalities in weighted Sobolev spaces associated with generalized Laguerre and generalized Hermite weights.


1983 ◽  
Vol 22 (2) ◽  
pp. 1226-1231
Author(s):  
A. N. Podkorytov ◽  
E. M. Dyn'kin
Keyword(s):  

1998 ◽  
Vol 50 (1) ◽  
pp. 152-166 ◽  
Author(s):  
G. Min

AbstractThis paper considers the rational system Pn(a1, a2,……,an) := with nonreal elements in paired by complex conjugation. It gives a sharp (to constant) Markov-type inequality for real rational functions in Pn(a1, a2,……an). The corresponding Markov-type inequality for high derivatives is established, as well as Nikolskii-type inequalities. Some sharp Markov- and Bernstein-type inequalities with curved majorants for rational functions in Pn(a1, a2,……an) are obtained, which generalize some results for the classical polynomials. A sharp Schur-type inequality is also proved and plays a key role in the proofs of our main results


2013 ◽  
Vol 219 (22) ◽  
pp. 10746-10752 ◽  
Author(s):  
J. Caballero ◽  
K. Sadarangani
Keyword(s):  

1997 ◽  
Vol 20 (3) ◽  
pp. 585-588 ◽  
Author(s):  
Fernando Garibay Bonales ◽  
Rigoberto Vera Mendoza

There is a formula (Gelfand's formula) to find the spectral radius of a linear operator defined on a Banach space. That formula does not apply even in normed spaces which are not complete. In this paper we show a formula to find the spectral radius of any linear and compact operatorTdefined on a complete topological vector space, locally convex. We also show an easy way to find a non-trivialT-invariant closed subspace in terms of Minkowski functional.


Author(s):  
Noori F. Al-Mayahi ◽  
Abbas M. Abbas

In this paper we give some definitions and properties of spectral theory in fuzzy Hilbert spaces also we introduce  definitions Invariant  under a linear operator  on fuzzy normed spaces and reduced  linear operator on fuzzy Hilbert spaces and we prove theorms  related to eigenvalue and eigenvectors ,eigenspace in fuzzy normed , Invariant and  reduced in fuzzy Hilbert spaces  and  show relationship between them.


2020 ◽  
pp. 1089-1097
Author(s):  
Sabah Aboud ◽  
Buthaina Abdul Hassan

Despite ample research on soft linear spaces, there are many other concepts that can be studied. We introduced in this paper several new concepts related to the soft operators, such as the invertible operator.  We investigated some properties of this kind of operators and defined the spectrum of soft linear operator along with a number of concepts related with this definition; the concepts of eigenvalue, eigenvector, eigenspace are defined. Finally the spectrum of the soft linear operator was divided into three disjoint parts.


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