Results 71 to 80 of about 32,914 (238)
Enhancing hard X‐ray beamline performance at SwissFEL through spontaneous radiation measurements
Journal of Synchrotron Radiation, Volume 33, Issue 1, Page 32-43, January 2026.Methods using spontaneous radiation to monitor and optimize the Aramis hard X‐ray beamline are presented, together with the eight‐year evolution of these improvements and the resulting record performance.The hard X‐ray beamline (Aramis) of the Swiss free‐electron laser (SwissFEL) has been in user operation since the end of 2017 and its performance has ...
Christoph Kittel +12 more
wiley +1 more source
Positive trigonometric polynomials
, 2003 We study the boundary of the nonnegative trigonometric polynomials from the algebraic point of view. In particularly, we show that it is a subset of an irreducible algebraic hypersurface and established its explicit form in terms of resultants.
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Bright and Dark Breathers on an Elliptic Wave in the Defocusing mKdV Equation
Studies in Applied Mathematics, Volume 156, Issue 1, January 2026.ABSTRACT Breathers on an elliptic wave background consist of nonlinear superpositions of a soliton and a periodic wave, both traveling with different wave speeds and interacting periodically in the space‐time. For the defocusing modified Korteweg–de Vries equation, the construction of general breathers has been an open problem since the elliptic wave ...
Dmitry E. Pelinovsky, Rudi Weikard
wiley +1 more source
Application of Chebyshev and trigonometric polynomials to the approximation of a solution of a singular integral equation with a multiplicative Cauchy kernel in the half-plane [PDF]
Opuscula Mathematica, 2008 In this article Chebyshev and trigonometric polynomials are used to construct an approximate solution of a singular integral equation with a multiplicative Cauchy kernel in the half-plane.
Paweł Karczmarek
doaj
Polynomial and trigonometric splines
, 2021 Classes of simple polynomial and simple trigonometric splines given by Fourier series are considered. It is shown that the class of simple trigonometric splines includes the class of simple polynomial splines. For some parameter values, the polynomial splines coincide with the trigonometric ones; this allows to transfer to such trigonometric splines ...
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On Some Cauchy Type Mean-Value Theorems with Applications
Communications in Advanced Mathematical SciencesSome Cauchy-type mean-value theorems for Chebychev’s inequality, Steffensen’s inequality, midpoint rule, and Simpson’s rule are presented. Furthermore, we give some applications for the obtained results using the exponential and logarithmic functions ...
Uğur Selamet Kırmacı
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Equivalence between various Shape Preserving Approximations of periodic functions
Researches in MathematicsWe show that the validity of Jackson-type estimates in comonotone and coconvex approximations of continuous $2\pi$-periodic functions by trigonometric polynomials is equivalent to the validity of the corresponding estimates of approximation by continuous
D. Leviatan, O.V. Motorna, I.O. Shevchuk
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Orthogonal sets of data windows constructed from trigonometric polynomials [PDF]
Suboptimal, easily computable substitutes for the discrete prolate-spheroidal windows used by Thomson for spectral estimation are given.
Greenhall, C. A.
core +1 more source
Integral inequalities for trigonometric polynomials in periodic Morrey spaces
Современная математика: Фундаментальные направленияIn this paper, we present a detailed exposition of Bernstein’s inequality, inequalities of different metrics and different dimensions for trigonometric polynomials in periodic Morrey spaces.
D. J. Joseph
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ON AN EXTREMAL PROBLEM FOR POLYNOMIALS WITH FIXED MEAN VALUE
Ural Mathematical Journal, 2016 Let \(T_n^+\) be the set of nonnegative trigonometric polynomials \(\tau_n\) of degree \(n\) that are strictly positive at zero. For \(0\le\alpha\le2\pi/(n+2),\) we find the minimum of the mean value of polynomial \((\cos\alpha-\cos{x})\tau_n(x)/\tau_n(0)
Alexander G. Babenko
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