Results 1 to 10 of about 101 (82)

Supershift properties for nonanalytic signals. [PDF]

open access: yesNanophotonics
Abstract The phenomenon of superoscillations is of great interest in microscopy, antenna design, and material sciences. This phenomenon has been generalized and has given rise to the concept of supershift, which is a far reaching extension that applies to functions that may present discontinuous derivatives. From this perspective, this is a notion that
Colombo F   +3 more
europepmc   +2 more sources

Stability in Generalized Functions

open access: yesAbstract and Applied Analysis, 2011
We consider the following additive functional equation with 𝑛-independent variables: ∑𝑓(𝑛𝑖=1𝑥𝑖∑)=𝑛𝑖=1𝑓(𝑥𝑖∑)+𝑛𝑖=1𝑓(𝑥𝑖−𝑥𝑖−1) in the spaces of generalized functions.
Young-Su Lee
doaj   +2 more sources

CONVOLUTORS FOR THE SPACE OF FOURIER HYPERFUNCTIONS

open access: yesJournal of the Korean Mathematical Society, 2005
The author of this paper defines the convolution of Fourier hyperfunctions and analyses its properties making use of the method given in the book [\textit{S. G. Gindikin} and \textit{L. R. Volevich}, ``Distributions and Convolution Equations'' (Gordon and Breach Sci. Publ.) (1992; Zbl 0760.46029)].
exaly   +4 more sources

On localization properties of Fourier transforms of hyperfunctions

open access: yesJournal of Mathematical Analysis and Applications, 2009
21 pages, final version, accepted for publication in J. Math.
exaly   +3 more sources

DENSENESS OF TEST FUNCTIONS IN THE SPACE OF EXTENDED FOURIER HYPERFUNCTIONS [PDF]

open access: yesBulletin of the Korean Mathematical Society, 2004
Let \(F_{(h,\nu)}\) be the space of differentiable functions \(\varphi(x)\) for which some sup-norm is finite. Then one has the continuous embedding \(F_{(h,\nu)}\subset F_{(h',\nu')}\), \(h\geq h'>0, \nu\geq\nu'\). Let \(\mathcal G=\bigcap_{h,\nu}F_{(h,\nu)}\) be endowed with the natural projective topology.
exaly   +2 more sources

Viscosity Limits for Zeroth‐Order Pseudodifferential Operators

open access: yesCommunications on Pure and Applied Mathematics, Volume 75, Issue 8, Page 1798-1869, August 2022., 2022
Abstract Motivated by the work of Colin de Verdière and Saint‐Raymond on spectral theory for zeroth‐order pseudodifferential operators on tori, we consider viscosity limits in which zeroth‐order operators, P, are replaced by P + iν Δ, ν > 0. By adapting the Helffer–Sjöstrand theory of scattering resonances, we show that, in a complex neighbourhood of ...
Jeffrey Galkowski, Maciej Zworski
wiley   +1 more source

Stability of Trigonometric Functional Equations in Generalized Functions

open access: yesJournal of Inequalities and Applications, 2010
We consider the Hyers-Ulam stability of a class of trigonometric functional equations in the spaces of generalized functions such as Schwartz distributions, Fourier hyperfunctions, and Gelfand generalized functions.
Jeongwook Chang, Jaeyoung Chung
doaj   +2 more sources

[Retracted] Cellular Imaging Analysis Algorithm‐Based Assessment and Prediction of Disease in Patients with Acute Lung Injury

open access: yesContrast Media &Molecular Imaging, Volume 2022, Issue 1, 2022., 2022
This paper uses cellular imaging analysis algorithms to assess and predict the condition of patients with acute lung injury. Given the unique optical properties of UCNPs, this paper designs a ratiometric upconversion fluorescent nanoprobe for the determination of nitric oxide (NO) content in living cells and tissues.
Liang Gao   +5 more
wiley   +1 more source

Stability of Quartic Functional Equations in the Spaces of Generalized Functions

open access: yesAdvances in Difference Equations, 2009
We consider the general solution of quartic functional equations and prove the Hyers-Ulam-Rassias stability. Moreover, using the pullbacks and the heat kernels we reformulate and prove the stability results of quartic functional equations in the spaces ...
Chung Soon-Yeong, Lee Young-Su
doaj   +2 more sources

Negative Powers of Contractions Having a Strong AA+ Spectrum

open access: yesMoroccan Journal of Pure and Applied Analysis, 2023
Zarrabi proved in 1993 that if the spectrum of a contraction T on a Banach space is a countable subset of the unit circle 𝕋, and if limn→+∞log(‖T−n‖)n=0{\lim _{n \to + \infty }}{{\log \left( {\left\| {{T^{ - n}}} \right\|} \right)} \over {\sqrt n ...
Esterle Jean
doaj   +1 more source

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