<p>In the paper, we give necessary and sufficient conditions for a continuous on <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\([-\pi ,\pi ]\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo stretchy="false">[</mo> <mo>-</mo> <mi>π</mi> <mo>,</mo> <mi>π</mi> <mo stretchy="false">]</mo> </mrow> </math></EquationSource> </InlineEquation> function <i>f</i> to belong to generalized uniform Lipschitz classes defined by iterates of the Jacobi-Dunkl translation in terms of Fourier-Jacobi-Dunkl coefficients. As a corollary, we obtain analogues of Boas equivalence results and their extensions due to Tikhonov and Moricz. We extend the Jacobi-Dunkl results of Tyr and Daher obtained for moduli of smoothness of even order and introduce a new type of modulus of smoothness of odd order for a similar study. Also, we prove sufficient conditions for generalized absolute convergence of Fourier-Jacobi-Dunkl series and show their sharpness in the important <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(L^2\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>L</mi> <mn>2</mn> </msup> </math></EquationSource> </InlineEquation> case using a new variant of the inverse approximation theorem.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

BOAS EQUIVALENCE RESULTS AND GENERALIZED ABSOLUTE CONVERGENCE OF JACOBI-DUNKL SERIES

  • Sergey Volosivets

摘要

In the paper, we give necessary and sufficient conditions for a continuous on \([-\pi ,\pi ]\) [ - π , π ] function f to belong to generalized uniform Lipschitz classes defined by iterates of the Jacobi-Dunkl translation in terms of Fourier-Jacobi-Dunkl coefficients. As a corollary, we obtain analogues of Boas equivalence results and their extensions due to Tikhonov and Moricz. We extend the Jacobi-Dunkl results of Tyr and Daher obtained for moduli of smoothness of even order and introduce a new type of modulus of smoothness of odd order for a similar study. Also, we prove sufficient conditions for generalized absolute convergence of Fourier-Jacobi-Dunkl series and show their sharpness in the important \(L^2\) L 2 case using a new variant of the inverse approximation theorem.