Numerical Algorithms and High-Performance Computing - CADMOS Chair

Chair

Related publications (333)

Block algorithms for reordering standard and generalized Schur forms

Daniel Kressner

Block algorithms for reordering a selected set of eigenvalues in a standard or generalized Schur form are proposed. Efficiency is achieved by delaying orthogonal transformations and (optionally) making use of level 3 BLAS operations. Numerical experiments ...

Association for Computing Machinery2006

Invariant subspaces of structured matrices are sometimes better conditioned with respect to structured perturbations than with respect to general perturbations. Sometimes they are not. This paper proposes an appropriate condition number c(S), for invariant ...

Society for Industrial and Applied Mathematics2006

The periodic QR algorithm is a disguised QR algorithm

Daniel Kressner

The periodic QR algorithm is a strongly backward stable method for computing the eigenvalues of products of matrices, or equivalently for computing the eigenvalues of block cyclic matrices. The main purpose of this paper is to show that this algorithm is n ...

Elsevier2006

Multiparametric Linear Complementarity Problems

Colin Neil Jones

The linear complementarity problem (LCP) is a general problem that unifies linear and quadratic programs and bimatrix games. In this paper, we present an efficient algorithm for the solution to multiparametric linear complementarity problems (pLCPs) that a ...

IEEE2006

Stewart's recently introduced Krylov-Schur algorithm is a modification of the implicitly restarted Arnoldi algorithm which employs reordered Schur decompositions to perform restarts and deflations in a numerically reliable manner. This paper describes a va ...

Springer Verlag2006

Constraints for the existence of flat and stable non-supersymmetric vacua in supergravity

Claudio Scrucca

We further develop on the study of the conditions for the existence of locally stable non-supersymmetric vacua with vanishing cosmological constant in supergravity models involving only chiral super fields. Starting from the two necessary conditions for fl ...

2006

A new MATLAB toolbox for computing eigenvalues and invariant subspaces of Hamiltonian and skew-Hamiltonian matrices is described. Based on orthogonal symplectic decompositions, the implemented algorithms are both numerically backward stable and structure-p ...

2005

On Matrix Rigidity and the Complexity of Linear Forms

Mahdi Cheraghchi Bashi Astaneh

The rigidity function of a matrix is defined as the minimum number of its entries that need to be changed in order to reduce the rank of the matrix to below a given parameter. Proving a strong enough lower bound on the rigidity of a matrix implies a nontri ...

2005

This letter shows that the matrix structure with 2/spl times/2 Alamouti sub-blocks remains invariant under several nontrivial matrix operations, including matrix inversion, Schur complementation, Riccati recursion, triangular factorization, and QR factoriz ...

IEEE2005

Matrix Implementations

Spyridon Pongas

The project consists in the study, implementation and comparison of binary matrix multiplication algorithms in C++. We consider Strassen’s algorithm (which is known to perform well over the real numbers) the Four Russians algorithm (which is designed for b ...

2005