Cover Image

Direct and inverse approximation theorems for functions defined in Damek–Ricci spaces

UDC 517.5 We introduce the notion of $k$th modulus of smoothness and establish the direct and inverse theorems in terms of the quantities $E_{s}(f)$&nbsp; and the moduli of&nbsp; smoothness generated by the spherical mean operator&nbsp; defined on the $L^{2}$-space for the Da...

Full description

Saved in:

Bibliographic Details
Date:	2024
Main Author:	El Ouadih, S.
Format:	Article
Language:	English
Published:	Institute of Mathematics, NAS of Ukraine 2024
Online Access:	https://umj.imath.kiev.ua/index.php/umj/article/view/7549
Tags:	Add Tag No Tags, Be the first to tag this record!
Journal Title:	Ukrains’kyi Matematychnyi Zhurnal
Download file:

Institution

Ukrains’kyi Matematychnyi Zhurnal

Similar Items

Direct and inverse approximation theorems for functions defined in Damek–Ricci spaces
by: El Ouadih
Published: (2024)

Ricci Solitons of Four-Dimensional Lorentzian Damek-Ricci Spaces
by: N. Sidhoumi
Published: (2020)

Direct and inverse theorems on approximation of functions defined on a sphere in the space S (p,q)(σ m)
by: Lasuriya, R. A., et al.
Published: (2007)

Direct and Inverse Theorems in the Theory of Approximation of Functions in the Space $S^p$
by: Serdyuk, A. S., et al.
Published: (2002)

Direct and inverse approximation theorems in the Besicovitch–Musielak–Orlicz spaces of almost periodic functions
by: S. O. Chaichenko, et al.
Published: (2022)

Direct and inverse approximation theorems in the Besicovitch – Musielak – Orlicz spaces of almost periodic functions
by: Chaichenko , S. O., et al.
Published: (2022)

Inverse theorems on approximation of periodic functions
by: Stepanets, O. I., et al.
Published: (1995)

Direct and inverse theorems on approximation of solution of operator equation
by: Gorbachuk, M.L., et al.
Published: (1999)

Direct and Inverse Theorems in the Theory of Approximation by the Ritz Method
by: Gorbachuk, M. L., et al.
Published: (2005)

The direct and inverse theorems of the approximation theory for solutions of differential equations in a Banach space
by: M. L. Horbachuk, et al.
Published: (2016)

Direct and inverse theorems on the approximation of 2р-periodic functions by Taylor–Abel–Poisson operators
by: Yu. Prestin, et al.
Published: (2017)

Direct and inverse theorems on the approximation of 2π -periodic functions by Taylor – Abel – Poisson operators
by: Prestin, J., et al.
Published: (2017)

Direct and inverse theorems of approximate methods for the solution of an abstract Cauchy problem
by: Torba, S. M., et al.
Published: (2007)

Inverse theorems of approximation on the average in regions with angles
by: Kolesnik, L. I., et al.
Published: (1970)

Inverse Jackson theorems in spaces with integral metric
by: Pichugov, S. A., et al.
Published: (2012)

Inverse theorems of approximation of regular (in convex polygons) functions by exponential polynomials in the integral metric
by: Melnik , Yu. I., et al.
Published: (1988)

The Inverse Theorem for the Generalized Derivative in Banach Spaces
by: Радзієвська, Олена, et al.
Published: (2023)

Ricci-pseudosymmetric almost $\alpha$-cosymplectic $(k,\mu ,\nu)$-spaces admitting Ricci solitons
by: Uygun, Pakize, et al.
Published: (2025)

Defining Pointwise Lower Scalar Curvature Bounds for 𝐶⁰ Metrics with Regularization by Ricci Flow
by: Burkhardt-Guim, Paula
Published: (2020)

Ricci soliton biharmonic hypersurfaces in the Euclidean space
by: N. Mosadegh, et al.
Published: (2021)

Ricci soliton biharmonic hypersurfaces in the Euclidean space
by: Mosadegh, N., et al.
Published: (2021)

Direct theorems of approximation for the functions regular in convex polygon by exponential polynomials in the integral metrics
by: Melnik, Yu. I., et al.
Published: (1988)

On the best approximations of functions defined on zero-dimensional groups
by: Timan, M. F., et al.
Published: (2012)

Ricci Solitons on Lorentzian Four-Dimensional Generalized Symmetric Spaces
by: A. Bouharis, et al.
Published: (2018)

Ricci Solitons on Lorentzian Four-Dimensional Generalized Symmetric Spaces
by: Bouharis, A., et al.
Published: (2018)

Collapsing Geometry with Ricci Curvature Bounded Below and Ricci Flow Smoothing
by: Huang, Shaosai, et al.
Published: (2020)

Ricci Solitons and Gradient Ricci Solitons on N(k)-Paracontact Manifolds
by: De U. Chand, et al.
Published: (2019)

Geometry of Ricci and $(\eta,\omega)$-Ricci solitons on the Sasaki–Kenmotsu manifold
by: Sangeetha, M., et al.
Published: (2025)

On Scalar and Ricci Curvatures
by: Besson, Gerard, et al.
Published: (2021)

MIYACHI’S AND HARDY’S THEOREMS ON THE FIRST HANKEL-CLIFFORD TRANSFORM
by: EL KASSIMI MOHAMMED,, et al.
Published: (2023)

Subextension and approximation of $m$-subharmonic functions with given boundary values
by: Amal, Hichame, et al.
Published: (2025)

Inverse problem in the space of generalized functions
by: H. P. Lopushanska, et al.
Published: (2016)

Inverse problem in the space of generalized functions
by: Lopushanskaya, G. P., et al.
Published: (2016)

Multiparameter inverse problem of approximation by functions with given supports
by: Nesterenko, A. N., et al.
Published: (2006)

On convergence of mappings in metric spaces with direct and inverse modulus conditions
by: E. A. Sevostjanov, et al.
Published: (2018)

On convergence of mappings in metric spaces with direct and inverse modulus conditions
by: Sevost'yanov, E. A., et al.
Published: (2018)

Third Hankel determinant for the class of analytic functions defined by Mathieu-type series related to a petal-shaped domain
by: Panigrahi, T., et al.
Published: (2024)

Approximation of continuous functions defined on the real axis by generalized Zygmund operators
by: Ostrovskaya, О. V., et al.
Published: (1999)

Conjectures and Open Questions on the Structure and Regularity of Spaces with Lower Ricci Curvature Bounds
by: Naber, Aaron
Published: (2020)

Third Hankel determinant for the class of analytic functions defined by Mathieu-type series related to a petal-shaped domain
by: T. Panigrahi, et al.
Published: (2024)