Results 41 to 50 of about 27,509 (180)
Some properties of Riesz means and spectral expansions
Electronic Journal of Differential Equations, 1999 It is well known that short-time expansions of heat kernels correlate to formal high-frequency expansions of spectral densities. It is also well known that the latter expansions are generally not literally true beyond the first term.
S. A. Fulling, R. A. Gustafson
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Journal of Inequalities and Applications, 2016 To start with, signals are dealt with as functions of one variable and images are shown by elements of two variables. The investigation of these ideas is directly related to the transpiring area of information technology.
Deepmala, Laurian-Ioan Piscoran
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Boundary unique continuation in planar domains by conformal mapping
Bulletin of the London Mathematical Society, Volume 58, Issue 5, May 2026.Abstract Let Ω⊂R2$\Omega \subset \mathbb {R}^2$ be a chord arc domain. We give a simple proof of the the following fact, which is commonly known to be true: a nontrivial harmonic function which vanishes continuously on a relatively open set of the boundary cannot have the norm of the gradient which vanishes on a subset of positive surface measure (arc ...
Stefano Vita
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Jensen's inequality for partial traces in von Neumann algebras
Bulletin of the London Mathematical Society, Volume 58, Issue 4, April 2026.Abstract Motivated by a recent result on finite‐dimensional Hilbert spaces, we prove Jensen's inequality for partial traces in semifinite von Neumann algebras. We also prove a similar inequality in the framework of general (non‐tracial) von Neumann algebras.
Mizanur Rahaman, Lyudmila Turowska
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The Steklov spectrum of spherical cylinders
Mathematika, Volume 72, Issue 2, April 2026.Abstract The Steklov problem on a compact Lipschitz domain is to find harmonic functions on the interior whose outward normal derivative on the boundary is some multiple (eigenvalue) of their trace on the boundary. These eigenvalues form the Steklov spectrum of the domain.
Spencer Bullent
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Convolution Operators and Bochner-Riesz Means on Herz-Type Hardy Spaces in the Dunkl Setting
International Journal of Mathematics and Mathematical Sciences, 2010 We study the Dunkl convolution operators on Herz-type Hardy spaces ℋα,2p and we establish a version of multiplier theorem for the maximal Bochner-Riesz operators on the Herz-type Hardy spaces ℋα,∞p.
A. Gasmi, F. Soltani
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Algebra Structure of Operator-Valued Riesz Means [PDF]
Journal of Operators, 2014 We characterize operator-valued Riesz means via an algebraic law of composition and establish their functional calculus accordingly. With this aim, we give a new integral expression of the Leibniz derivation rule for smooth functions.
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Riesz means of certain arithmetic functions
Journal of Number Theory, 2020 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
William Duke, Ha Nam Nguyen
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Duality for Evolutionary Equations With Applications to Null Controllability
Mathematical Methods in the Applied Sciences, Volume 49, Issue 5, Page 4144-4166, 30 March 2026.ABSTRACT We study evolutionary equations in exponentially weighted L2$$ {\mathrm{L}}^2 $$‐spaces as introduced by Picard in 2009. First, for a given evolutionary equation, we explicitly describe the ν$$ \nu $$‐adjoint system, which turns out to describe a system backwards in time. We prove well‐posedness for the ν$$ \nu $$‐adjoint system. We then apply
Andreas Buchinger, Christian Seifert
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Ibn Al-Haitham Journal for Pure and Applied Sciences, 2017 The aim of this paper is to prove a theorem on the Riesz means of expansions with respect to Riesz bases, which extends the previous results of [1] and [2] on the Schrödinger operator and the ordinary differential operator of 4-th order to the ...
A. A. Aswhad
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