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This paper offers a newly created integral approach for operators employing the orthogonal modified Laguerre polynomials and P\u{a}lt\u{a}nea basis. These operators approximate the functions over the interval $[0,\infty)$. Further, the…

Functional Analysis · Mathematics 2024-05-14 Kapil Kumar , Naokant Deo , Durvesh Kumar Verma

We define a notion of pseudo-unitarizability for weight modules over a generalized Weyl algebra (of rank one, with commutative coeffiecient ring $R$), which is assumed to carry an involution of the form $X^*=Y$, $R^*\subseteq R$. We prove…

Rings and Algebras · Mathematics 2012-10-26 Jonas T. Hartwig

Several new inequalities for moduli of smoothness and errors of the best approximation of a function and its derivatives in the spaces $L_p$, $0<p<1$, are obtained. For example, it is shown that for any $0<p<1$ and $k,\,r\in \mathbb{N}$ one…

Classical Analysis and ODEs · Mathematics 2016-12-26 Yurii Kolomoitsev

Theorems of Khintchine, Groshev, Jarn\'ik, and Besicovitch in Diophantine approximation are fundamental results on the metric properties of $\Psi$-well approximable sets. These foundational results have since been generalised to the…

Number Theory · Mathematics 2025-07-09 Gerardo González Robert , Mumtaz Hussain , Nikita Shulga , Benjamin Ward

We consider the problem of finding a best uniform approximation to the standard monomial on the unit ball in $\bbC^2$ by polynomials of lower degree with complex coefficients. We reduce the problem to a one-dimensional weighted minimization…

Classical Analysis and ODEs · Mathematics 2010-02-11 I. Moale , P. Yuditskii

Polynomial approximation is studied in the Sobolev space $W_p^r(w_{\alpha,\beta})$ that consists of functions whose $r$-th derivatives are in weighted $L^p$ space with the Jacobi weight function $w_{\alpha,\beta}$. This requires…

Classical Analysis and ODEs · Mathematics 2017-11-01 Yuan Xu

In this article we introduce and study uniform and non-uniform approximate lattices in locally compact second countable (lcsc) groups. These are approximate subgroups (in the sense of Tao) which simultaneously generalize lattices in lcsc…

Group Theory · Mathematics 2018-11-14 Michael Björklund , Tobias Hartnick

In this paper the author considers a particular type of polynomials with integer coefficients, consisting of a perfect power and two norm forms of abelian number fields with coprime discriminants. It is shown that such a polynomial…

Number Theory · Mathematics 2015-11-30 Jeongho Park

We establish a correspondence between inverse sumset theorems (which can be viewed as classifications of approximate (abelian) groups) and inverse theorems for the Gowers norms (which can be viewed as classifications of approximate…

Number Theory · Mathematics 2015-05-13 Ben Green , Terence Tao

For any $p\in[1,\infty)$, we prove that the set of simple functions taking at most $k$ different values is proximinal in B\"ochner spaces $L^p(X)$ whenever $X$ is a dual Banach space with $w^*$-sequentially compact unit ball. With…

Functional Analysis · Mathematics 2024-04-24 Guillaume Grelier , Jaime San Martín

For the principal eigenvalue of discrete weighted $p$-Laplacian on the set of nonnegative integers, the convergence of an approximation procedure and the inverse iteration is proved. Meanwhile, in the proof of the convergence, the…

Probability · Mathematics 2019-03-11 Yue-Shuang Li

In the Orlicz type spaces ${\mathcal S}_{M}$, we prove direct and inverse approximation theorems in terms of the best approximations of functions and moduli of smoothness of fractional order. We also show the equivalence between moduli of…

Classical Analysis and ODEs · Mathematics 2020-04-22 Stanislav Chaichenko , Andrii Shidlich , Fahreddin Abdullayev

This article contributes to the new summation of Sz\'asz operators with the help of Appell polynomials of class $A^{2}$. We verified Bohman-Korovkin's theorem and prove the convergence results like Lipschitz-type space, Voronvaskaja-type…

Classical Analysis and ODEs · Mathematics 2023-08-08 Naokant Deo , Chandra Prakash , D. K. Verma

In this note, we demonstrate the convergence of the Demailly approximation of a general (weakly) upper semi-continuous weight.

Complex Variables · Mathematics 2025-04-03 Shijie Bao , Qi'an Guan

Let $(X,\nu,T)$ be a measure-preserving system, and let $P_1,\ldots, P_k$ be polynomials with integer coefficients. We prove that, for any $f_1,\ldots, f_k\in L^{\infty}(X)$, the M\"obius-weighted polynomial multiple ergodic averages…

Dynamical Systems · Mathematics 2024-08-06 Joni Teräväinen

In this work, we study asymptotic zero distribution of random multi-variable polynomials which are random linear combinations $\sum_{j}a_jP_j(z)$ with i.i.d coefficients relative to a basis of orthonormal polynomials $\{P_j\}_j$ induced by…

Complex Variables · Mathematics 2018-05-07 Turgay Bayraktar

In this paper, we prove a quantitative approximation result by orthonormal polynomials associated to an exponential weight of the form e -$\Phi$ , where $\Phi$ is an even polynomial with positive leading coefficient. This result is a…

Numerical Analysis · Mathematics 2024-12-19 Bastien Grosse

Asymptotic approximations to the zeros of Jacobi polynomials are given, with methods to obtain the coefficients in the expansions. These approximations can be used as standalone methods for the non-iterative computation of the nodes of…

Numerical Analysis · Mathematics 2019-03-05 Amparo Gil , Javier Segura , Nico M. Temme

The main goal of this paper is to introduce a framework for infinitesimal deformation problems, using new methods coming from operadic calculus. We construct an adjunction between infinitesimal deformation problems over some type of…

Algebraic Topology · Mathematics 2024-05-31 Brice Le Grignou , Victor Roca i Lucio

We give an elementary proof of an analogue of Fej\'er's theorem in weighted Dirichlet spaces with superharmonic weights. This provides a simple way of seeing that polynomials are dense in such spaces.

Complex Variables · Mathematics 2020-11-06 Javad Mashreghi , Thomas Ransford