Results 1 to 10 of about 156 (30)

Symmetric Jacobians [PDF]

open access: yesOpen Mathematics, 2014
This article is about polynomial maps with a certain symmetry and/or antisymmetry in their Jacobians, and whether the Jacobian Conjecture is satisfied for such maps, or whether it is sufficient to prove the Jacobian Conjecture for such maps.
Bondt Michiel
doaj   +4 more sources

Singular matrices that are products of two idempotents or products of two nilpotents

open access: yesSpecial Matrices, 2021
Over commutative domains we characterize the singular 2 × 2 matrices which are products of two idempotents or products of two nilpotents. The relevant casees are the matrices with zero second row and the singular matrices with only nonzero entries.
Călugăreanu Grigore
doaj   +1 more source

Combined matrix of diagonally equipotent matrices

open access: yesSpecial Matrices, 2023
Let C(A)=A∘A−T{\mathcal{C}}\left(A)=A\circ {A}^{-T} be the combined matrix of an invertible matrix AA, where ∘\circ means the Hadamard product of matrices.
Bru Rafael   +4 more
doaj   +1 more source

On the spectrum of linear combinations of finitely many diagonalizable matrices that mutually commute

open access: yesSpecial Matrices, 2021
We propose an algorithm, which is based on the method given by Kişi and Özdemir in [Math Commun, 23 (2018) 61], to handle the problem of when a linear combination matrix X=∑i=1mciXiX = \sum\nolimits_{i = 1}^m {{c_i}{X_i}} is a matrix such that its ...
Kişi Emre   +3 more
doaj   +1 more source

Algebraic conditions and the sparsity of spectrally arbitrary patterns

open access: yesSpecial Matrices, 2021
Given a square matrix A, replacing each of its nonzero entries with the symbol * gives its zero-nonzero pattern. Such a pattern is said to be spectrally arbitrary when it carries essentially no information about the eigenvalues of A.
Deaett Louis, Garnett Colin
doaj   +1 more source

Schrödinger’s tridiagonal matrix

open access: yesSpecial Matrices, 2021
In the third part of his famous 1926 paper ‘Quantisierung als Eigenwertproblem’, Schrödinger came across a certain parametrized family of tridiagonal matrices whose eigenvalues he conjectured.
Kovačec Alexander
doaj   +1 more source

A universal gap for non-spin quantum control systems [PDF]

open access: yes, 2020
We prove the existence of a universal gap for minimum time controllability of finite dimensional quantum systems, except for some basic representations of spin groups.
Gauthier, Jean-Paul, Rossi, Francesco
core   +2 more sources

Modularity bounds for clusters located by leading eigenvectors of the normalized modularity matrix [PDF]

open access: yes, 2016
Nodal theorems for generalized modularity matrices ensure that the cluster located by the positive entries of the leading eigenvector of various modularity matrices induces a connected subgraph.
Fasino, Dario, Tudisco, Francesco
core   +3 more sources

The expected adjacency and modularity matrices in the degree corrected stochastic block model

open access: yesSpecial Matrices, 2018
We provide explicit expressions for the eigenvalues and eigenvectors of matrices that can be written as the Hadamard product of a block partitioned matrix with constant blocks and a rank one matrix.
Fasino Dario, Tudisco Francesco
doaj   +1 more source

Numerical construction of structured matrices with given eigenvalues

open access: yesSpecial 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

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