Results 11 to 20 of about 43 (41)
Numerical construction of structured matrices with given eigenvalues
Special Matrices, 2019 We consider a structured inverse eigenvalue problem in which the eigenvalues of a real symmetric matrix are specified and selected entries may be constrained to take specific numerical values or to be nonzero.
Sutton Brian D.
doaj +1 more source
EURO Journal on Computational Optimization, 2019 The plain Newton-min algorithm for solving the linear complementarity problem (LCP) “0⩽x⊥(Mx+q)⩾0” can be viewed as an instance of the plain semismooth Newton method on the equational version “min(x,Mx+q)=0” of the problem.
Jean-Pierre Dussault +2 more
doaj +1 more source
A note on completing quasi-distance and distance matrices
Special Matrices, 2019 We give a necessary and sufficient condition for the existence of a quasi-distance matrix where some positive off-diagonal entries have been prescribed. Moreover, we give an algorithm for obtaining such a matrix.
Zhang Yulin +2 more
doaj +1 more source
On nilpotent matrices that are unit-regular [PDF]
In this paper, we characterize regular nilpotent 2 × 2 matrices over Bézout domains and prove that they are unit-regular. We also demonstrate that nilpotent n × n matrices over division rings are unit-regular.
CĂLUGĂREANU, Grigore
core +2 more sources
Some spectral bounds for the harmonic matrix
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2017 The aim of this note is to establish new spectral bounds for the harmonic matrix.
Das Kinkar Ch., Fonseca Carlos M. da
doaj +1 more source
Patterns with several multiple eigenvalues
Special Matrices, 2014 Identified are certain special periodic diagonal matrices that have a predictable number of pairedeigenvalues. Since certain symmetric Toeplitz matrices are special cases, those that have several multiple 5eigenvalues are also investigated further.
Dorsey J., Johnson C.R., Wei Z.
doaj +1 more source
Variations in the sub-defect of doubly substochastic matrices
Special MatricesThe sub-defect of a doubly stochastic matrix AA, denoted as sd(A)=⌈n−sum(A)⌉sd\left(A)=\lceil n-{\rm{sum}}\left(A)\rceil , is defined as the minimum number of rows and columns required to be added to transform the doubly substochastic matrix into a ...
Cao Lei +2 more
doaj +1 more source
Special MatricesA nonzero element aa is called 1-Sylvester in a ring RR, if there exist b,c∈Rb,c\in R such that 1=ab+ca1=ab+ca. In this article, we study such elements, mainly in matrix rings over commutative rings.
Călugăreanu Grigore
doaj +1 more source
Idempotents which are products of two nilpotents
Special MatricesOver any GCD (greatest common divisor) commutative domain we show that the nontrivial 2×22\times 2 idempotent matrices are products of two nilpotent matrices. In order to find explicitly such decompositions, two procedures are described.
Călugăreanu Grigore, Pop Horia F.
doaj +1 more source