36 citations · 164 across the 19 of their papers we have counts for
7 papers · 1 filter
Recursive expansion of the matrix step function using polynomials of degree eight
Emanuel H. Rubensson, Elias Jarlebring, Gustaf Lorentzon
We consider the problem of efficiently computing the matrix step function of a large dense symmetric matrix. To this end, we introduce a recursive polynomial expansion method in wh…
Higher order derivatives of matrix functions
Emanuel H. Rubensson
We present theory for general partial derivatives of matrix functions on the form where is a matrix path of several variables (). Building on re…
Sparse approximate matrix-matrix multiplication for density matrix purification with error control
Anton G. Artemov, Emanuel H. Rubensson
We propose a method for strict error control in sparse approximate matrix-matrix multiplication. The method combines an error bound and a parameter sweep to select an appropriate t…
Parallelization and scalability analysis of inverse factorization using the Chunks and Tasks programming model
Anton G. Artemov, Elias Rudberg, Emanuel H. Rubensson
We present three methods for distributed memory parallel inverse factorization of block-sparse Hermitian positive definite matrices. The three methods are a recursive variant of th…
Localized inverse factorization
Emanuel H. Rubensson, Anton G. Artemov, Anastasia Kruchinina +1
We propose a localized divide and conquer algorithm for inverse factorization of Hermitian positive definite matrices with localized structure, e.g. exponential…
A density matrix approach to the convergence of the self-consistent field iteration
Parikshit Upadhyaya, Elias Jarlebring, Emanuel H. Rubensson
In this paper, we present a local convergence analysis of the self-consistent field (SCF) iteration using the density matrix as the state of a fixed-point iteration. Sufficient and…
On the condition number and perturbation of matrix functions for Hermitian matrices
Elias Jarlebring, Emanuel H. Rubensson
Consider a matrix function f defined for Hermitian matrices. The purpose of this paper is two-fold. We derive new results for the absolute structured condition number of the matrix…