Search Results - "Capizzano, S. Serra"

Eigenvalues and eigenvectors of banded Toeplitz matrices and the related symbols by Ekström, S.‐E., Serra‐Capizzano, S.

“…Summary It is known that for a tridiagonal Toeplitz matrix, having on the main diagonal the constant a0 and on the two first off‐diagonals the constants…”
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Staggered discontinuous Galerkin methods for the incompressible Navier–Stokes equations: Spectral analysis and computational results by Dumbser, M., Fambri, F., Furci, I., Mazza, M., Serra‐Capizzano, S., Tavelli, M.

“…Summary The goal of this paper is to create a fruitful bridge between the numerical methods for approximating PDEs in fluid dynamics and the (iterative)…”
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Singular-value (and eigenvalue) distribution and Krylov preconditioning of sequences of sampling matrices approximating integral operators by Al-Fhaid, A.S., Serra-Capizzano, S., Sesana, D., Zaka Ullah, M.

“…SUMMARYLet k( ⋅ , ⋅ ) be a continuous kernel defined on Ω × Ω, Ω compact subset of Rd, d ⩾1, and let us consider the integral operator K̃ from C(Ω) into C(Ω)…”
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A level-set multigrid technique for nonlinear diffusion in the numerical simulation of marble degradation under chemical pollutants by Coco, A., Semplice, M., Serra Capizzano, S.

“…Having in mind the modelling of marble degradation under chemical pollutants, e.g. the sulfation process, we consider governing nonlinear diffusion equations…”
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A Family of Iterative Methods for Solving Systems of Nonlinear Equations Having Unknown Multiplicity by Ahmad, Fayyaz, Serra-Capizzano, S, Ullah, Malik Zaka, Al-Fhaid, A S

“…The singularity of Jacobian happens when we are looking for a root, with multiplicity greater than one, of a system of nonlinear equations. The purpose of this…”
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A matrix-theoretic spectral analysis of incompressible Navier–Stokes staggered DG approximations and a related spectrally based preconditioning approach by Mazza, M., Semplice, M., Serra-Capizzano, S., Travaglia, E.

“…The incompressible Navier–Stokes equations are solved in a channel, using a Discontinuous Galerkin method over staggered grids. We study the structure and the…”
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Solving systems of nonlinear equations when the nonlinearity is expensive by Qasim, Sabahat, Ali, Zulifqar, Ahmad, Fayyaz, Serra-Capizzano, S., Ullah, Malik Zaka, Mahmood, Arshad

“…Construction of multi-step iterative method for solving system of nonlinear equations is considered, when the nonlinearity is expensive. The proposed method is…”
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How to prove that a preconditioner cannot be superlinear by Capizzano, S. Serra, Tyrtyshnikov, E.

“…In the general case of multilevel Toeplitz matrices, we recently proved that any multilevel circulant preconditioner is not superlinear (a cluster it may…”
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Two-grid methods for banded linear systems from DCT III algebra by Chan, R. H., Serra-Capizzano, S., Tablino-Possio, C.

“…We describe a two‐grid and a multigrid method for linear systems whose coefficient matrices are point or block matrices from the cosine algebra generated by a…”
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Spectral analysis and preconditioning techniques for radial basis function collocation matrices by Cavoretto, R., De Rossi, A., Donatelli, M., Serra-Capizzano, S.

“…SUMMARY Meshless collocation methods based on radial basis functions lead to structured linear systems, which, for equispaced grid points, have almost a…”
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Perturbation of operators and approximation of spectrum by KUMAR, K, NAMBOODIRI, M N N, SERRA-CAPIZZANO, S

“…Let A ( x ) be a norm continuous family of bounded self-adjoint operators on a separable Hilbert space ℍ and let A ( x ) n be the orthogonal compressions of A…”
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The conditioning of FD matrix sequences coming from semi-elliptic differential equations by Noutsos, D., Serra Capizzano, S., Vassalos, P.

“…In this paper we are concerned with the study of spectral properties of the sequence of matrices { A n ( a ) } coming from the discretization, using centered…”
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Matrix algebra preconditioners for multilevel Toeplitz systems do not insure optimal convergence rate by Noutsos, D., Serra Capizzano, S., Vassalos, P.

“…In the last decades several matrix algebra optimal and superlinear preconditioners (those assuring a strong clustering at the unity) have been proposed for the…”
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Distribution results on the algebra generated by Toeplitz sequences: a finite-dimensional approach by Capizzano, S.Serra

“…Let a be an L 1 symbol defined on Q d , Q=(−π,π) with d⩾1 and let us consider the multi-indexed sequence of Toeplitz matrices { T n ( a)} with n∈ N d . It is…”
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Block band Toeplitz preconditioners derived from generating function approximations : analysis and applications by NOUTSOS, D, SERRA CAPIZZANO, S, VASSALOS, P

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Practical Band Toeplitz Preconditioning and Boundary Layer Effects by Serra-Capizzano, S.

“…In the last decade many efficient iterative solvers for n×n Hermitian positive definite Toeplitz systems have been devised. Many of them are based on band…”
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Fast Toeplitz eigenvalue computations, joining interpolation-extrapolation matrix-less algorithms and simple-loop theory: The preconditioned setting by Bogoya, M., Serra-Capizzano, S., Vassalos, P.

“…Under appropriate technical assumptions, the simple-loop theory allows to derive various types of asymptotic expansions for the eigenvalues of Toeplitz…”
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GLT sequences and automatic computation of the symbol by Sarathkumar, N.S., Serra-Capizzano, S.

“…Spectral and singular value symbols are valuable tools to analyse the eigenvalue or singular value distributions of matrix-sequences in the Weyl sense. More…”
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Eigenvalue superposition for Toeplitz matrix-sequences with matrix order dependent symbols by Bogoya, M., Grudsky, S.M., Serra-Capizzano, S.

“…The eigenvalues of Toeplitz matrices Tn(f) with a real-valued generating function f, satisfying some conditions and tracing out a simple loop over the interval…”
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Asymptotic behavior of the condition number of two-level Toeplitz matrix sequences by Noutsos, D., Serra Capizzano, S., Vassalos, P.

“…In this note we give condition number estimates for two-level Toeplitz matrices generated by bivariate 2 π-periodic weakly sectorial symbols (the largest class…”
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