Results 41 to 50 of about 413 (185)

Breaking Barriers in High‐Order Spectral Methods: The Intrinsic Matrix Approach

International Journal for Numerical Methods in Engineering, Volume 127, Issue 5, 15 March 2026.
ABSTRACT This paper introduces a unified framework in Hilbert spaces for applying high‐order differential operators in bounded domains using Chebyshev, Legendre, and Fourier spectral methods. By exploiting the banded structure of differentiation matrices and embedding boundary conditions directly into the operator through a scaling law relating ...
Osvaldo Guimarães, José R. C. Piqueira
wiley   +1 more source

Dual Toeplitz Operators on the Orthogonal Complement of the Generalized Fock Space

Mathematics
We characterize the boundedness and compactness of dual Toeplitz operators on the orthogonal complement of the generalized Fock space. We study the problem when the finite sum of the dual Toeplitz products is compact.
Baoli Xie, Jianxiang Dong, Caochuan Ma
doaj   +1 more source

Asymmetric truncated Toeplitz operators and Toeplitz operators with matrix symbol [PDF]

Journal of Operator Theory, 2017
Truncated Toeplitz operators and their asymmetric versions are studied in the context of the Hardy space $H^p$ of the half-plane for ...
Câmara, M. Cristina, Partington, Jonathan R.   +1 more
openaire   +2 more sources

Online Spatiotemporally Constrained Reconstruction for Real‐Time Interactive MRI

Magnetic Resonance in Medicine, Volume 95, Issue 3, Page 1644-1652, March 2026.
ABSTRACT Purpose To develop a low‐latency dynamic MRI reconstruction that provides better spatial and temporal fidelity than contemporary online reconstruction, for localization. Methods We utilize online spatiotemporally constrained reconstruction (STCR) using a computationally efficient augmented Lagrangian solution and a limited number of iterations
Duc H. Le, Prakash Kumar, Ecrin Yagiz, Ye Tian, Krishna S. Nayak   +4 more
wiley   +1 more source

Properties of two variables Toeplitz type operators

Annales Universitatis Paedagogicae Cracoviensis: Studia Mathematica, 2016
The investigation of properties of generalized Toeplitz operators with respect to the pairs of doubly commuting contractions (the abstract analogue of classical two variable Toeplitz operators) is proceeded. We especially concentrate on the condition of
Elżbieta Król-Klimkowska, Marek Ptak
doaj   +1 more source

DREAMER: Rapid and Simultaneous Multiple Contrast Magnetic Resonance Imaging of Solid and Soft Tissue

Magnetic Resonance in Medicine, Volume 95, Issue 3, Page 1513-1527, March 2026.
ABSTRACT Purpose Pediatric craniofacial imaging may involve examination of both the skull and brain tissues via CT and MRI, respectively. DREAMER (Dual Repetition and Echo Acquisition with Multi‐contrast Encoding and Reconstruction) simultaneously acquires solid‐ and soft‐tissue images, potentially providing a rapid, high‐resolution, and radiation‐free
Brian‐Tinh Duc Vu, Nada Kamona, Felix W. Wehrli, Rajiv S. Deshpande, Hee Kwon Song, Allison Hu, Emily Baccaglini, Scott P. Bartlett, Chamith S. Rajapakse   +8 more
wiley   +1 more source

Commutative C⁎-Algebras of Toeplitz Operators via the Moment Map on the Polydisk

Journal of Function Spaces, 2016
We found that in the polydisk Dn there exist (n+1)(n+2)/2 different classes of commutative C⁎-algebras generated by Toeplitz operators whose symbols are invariant under the action of maximal Abelian subgroups of biholomorphisms.
Mauricio Hernández-Marroquin, Armando Sánchez-Nungaray, Luis Alfredo Dupont-García   +2 more
doaj   +1 more source

Stability and Instability of Time‐Domain Boundary Element Methods for the Acoustic Neumann Problem

Proceedings in Applied Mathematics and Mechanics, Volume 26, Issue 1, March 2026.
ABSTRACT This work presents a stable time‐domain boundary element method for the acoustic wave equation in three‐dimensional unbounded domains. Other formulations of time‐domain boundary element methods based on retarded potential operators are known to exhibit stability issues, which often hinder their use in industrial contexts.
Simon Schneider, Ceyhun Özdemir, Heiko Gimperlein, Karsten Urban, Bernd Graf   +4 more
wiley   +1 more source

Commuting Toeplitz Operators With Mixed Quasihomogeneous and Analytic Symbols

Journal of Mathematics
A major open problem in the theory of Toeplitz operators on the analytic Bergman space over the unit disk is the characterization of the commutant of a given Toeplitz operator, that is, the set of all bounded Toeplitz operators that commute with it.
Aissa Bouhali, Issam Louhichi, Abdelrahman Yousef   +2 more
doaj   +1 more source

On moments of the derivative of CUE characteristic polynomials and the Riemann zeta function

Journal of the London Mathematical Society, Volume 113, Issue 3, March 2026.
Abstract We study the derivative of the characteristic polynomial of N×N$N \times N$ Haar‐distributed unitary matrices. We obtain new explicit formulae for complex‐valued moments when the spectral variable is inside the unit disc, in the limit N→∞$N \rightarrow \infty$.
Nicholas Simm, Fei Wei
wiley   +1 more source