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Approximation properties of multivariate Kantorovich-Kotelnikov type operators generated by different band-limited functions are studied. In particular, a wide class of functions with discontinuous Fourier transform is considered. The…

Classical Analysis and ODEs · Mathematics 2018-11-20 Yu. Kolomoitsev , M. Skopina

Given a convergent sequence of nodes we present a one-dimensional-holomorphic-function version of the Newton interpolation method of polynomials. It also generalises the Taylor and the Laurent formula. In other words, we present an…

Complex Variables · Mathematics 2012-02-28 Tomasz Sobieszek

The optimal sufficient conditions for the $L^p$-to-$L^q$ compactness of commutators of singular integral operators of both Calder\'on-Zygmund and of rough type are shown in the different exponent ranges $``q>p"$, $``q=p"$ and $``q<p"$ to…

Classical Analysis and ODEs · Mathematics 2025-12-08 Tuomas Oikari

We consider the problem of uniform interpolation of functions with values in a complex inner product space of finite dimension. This problem can be casted within a modified weighted pluripotential theoretic framework. Indeed, in the…

Complex Variables · Mathematics 2025-04-10 Ludovico Bruni Bruno , Federico Piazzon

In this paper we present several new classes of logarithmically completely monotonic functions. Our functions have in common that they are defined in terms of the $q-$gamma and $q-$digamma functions. As an applications of this results, some…

Classical Analysis and ODEs · Mathematics 2015-12-21 Khaled Mehrez

We consider functions $f$ of two real variables, given as trigonometric functions over a finite set $F$ of frequencies. This set is assumed to be closed under rotations in the frequency plane of angle $\frac{2k\pi}{M}$ for some integer $M$.…

Numerical Analysis · Mathematics 2016-12-02 Jean-Paul Gauthier , Dario Prandi

We present an elementary proof of a general version of Montel's theorem in several variables which is based on the use of tensor product polynomial interpolation. We also prove a Montel-Popoviciu's type theorem for functions…

Classical Analysis and ODEs · Mathematics 2014-07-03 A. G. Aksoy , J. M. Almira

In this paper, we consider a $q$-analogue of the Dunkl operator on $\mathbb{R}$, we define and study its associated Fourier transform which is a $q$-analogue of the Dunkl transform. In addition to several properties, we establish an…

Quantum Algebra · Mathematics 2008-01-03 Néji Bettaibi , Rym H. bettaieb

We estimate the Lebesgue constants for Lagrange interpolation processes on one or several intervals by rational functions with fixed poles. We admit that the poles have accumulation points on the intervals. To prove it we use an analog of…

Complex Variables · Mathematics 2024-06-19 Sergei Kalmykov , Alexey Lukashov

Different types of sinc integrals are investigated when the standard sine function is replaced by the generalised $\sin_{p,q}$ in two parameters. A striking generalisation of the improper Dirichlet integral is achieved. A second surprising…

Classical Analysis and ODEs · Mathematics 2021-02-05 Houry Melkonian , Shingo Takeuchi

We obtain necessary and sufficient conditions on weights for the generalized Fourier-type transforms to be bounded between weighted $L^p-L^q$ spaces. As an important example, we investigate transforms with kernel of power type, as for…

Classical Analysis and ODEs · Mathematics 2018-12-06 A. Debernardi

In this paper we characterize the subspace of $\mathcal{L}_{q,1,v}$ of function which are the q-Bessel Fourier transform of positive functions in $\mathcal{L}_{q,1,v}$. As application we give a q-version of the Bochner's theorem.

Classical Analysis and ODEs · Mathematics 2026-05-12 Lazhar Dhaouadi

In this short note we prove a conjecture for the interval $(0,1)$, related to a logarithmically completely monotonic function, presented in \cite{BG}. Then, we extend by proving a more generalized theorem. At the end we pose an open problem…

Classical Analysis and ODEs · Mathematics 2016-01-05 Valmir Krasniqi , Armend Sh. Shabani

In this manuscript we lift the theory of r-quasisymmetric functions to the theory of Hopf monoids. We provide a general method of interpolating between two Hopf monoids, one being the free monoid on a positive comonoid and the other being…

Combinatorics · Mathematics 2026-03-23 Aaron Lauve , Anthony Lazzeroni

In this paper some Tur\'an type inequalities for classical and generalized Mittag-Leffler functions are considered. The method is based on proving monotonicity for special ratio of sections for series of Mittag-Leffler functions. Some…

Classical Analysis and ODEs · Mathematics 2018-11-20 Sergei M. Sitnik , Khaled Mehrez

A new generalization of multiquadric functions $\phi(x)=\sqrt{c^{2d}+||x||^{2d}}$, where $x\in\mathbb{R}^n$, $c\in \mathbb{R}$, $d\in \mathbb{N}$, is presented to increase the accuracy of quasi-interpolation further. With the restriction to…

Numerical Analysis · Mathematics 2023-09-07 Mathis Ortmann , Martin Buhmann

We study a family of convolution operators whose symbols and kernels have singularity on the light-cone in $\mathbb{R}^{n+1}$. First, we prove a desired ${\bf L}^p\to {\bf L}^q$ norm inequality which has been left open. Moreover, we obtain…

Classical Analysis and ODEs · Mathematics 2025-11-26 Zipeng Wang

We generalize the classic Fourier transform operator $\mathcal{F}_{p}$ by using the Henstock-Kurzweil integral theory. It is shown that the operator equals the $HK$-Fourier transform on a dense subspace of $\mathcal{ L}^p$, $1<p\leq 2$. In…

Classical Analysis and ODEs · Mathematics 2020-07-23 Juan H. Arredondo , M. Guadalupe Morales , Manuel Bernal G

In the first part of the paper we give a definition of G_q-function and we establish a regularity result, obtained as a combination of a q-analogue of the Andre'-Chudnovsky Theorem [And89, VI] and Katz Theorem [Kat70, \S 13]. In the second…

Number Theory · Mathematics 2010-01-13 Lucia Di Vizio

The inclusions between the Besov spaces $B^q$, the Bloch space $\mathcal{B}$ and the standard weighted Bergman spaces $A^p_\alpha$ are completely understood, but the norms of the corresponding inclusion operators are in general unknown. In…

Complex Variables · Mathematics 2021-12-21 Adrián Llinares