Results 1 to 10 of about 641 (72)

Pairs of k-step reachability and m-step observability matrices

open access: yesSpecial Matrices, 2013
Let $V$ and $W$ be matrices of size $ n \times pk$ and $q m \times n $, respectively. A necessary and sufficient condition is given for the existence of a triple $(A,B,C)$ such that $V$ a $k$-step reachability matrix of $(A,B)$ and $W$ an $m$-step ...
Ferrante Augusto, Wimmer Harald K.
doaj   +2 more sources

Graph complement conjecture for classes of shadow graphs

open access: yesOperators and Matrices, 2021
The real minimum semidefinite rank of a graph G , denoted mrR+(G) , is defined to be the minimum rank among all real symmetric positive semidefinite matrices whose zero/nonzero pattern corresponds to the graph G .
Monsikarn Jansrang, S. Narayan
semanticscholar   +1 more source

Independence, infinite dimension, and operators

open access: yesMoroccan Journal of Pure and Applied Analysis, 2023
In [Appl. Comput. Harmon. Anal., 46 (2019), 664673] O. Christensen and M. Hasannasab observed that assuming the existence of an operator T sending en to en+1 for all n ∈ ℕ (where (en)n∈ℕ is a sequence of vectors) guarantees that (en)n∈ℕ is linearly ...
Idrissi Nizar El, Kabbaj Samir
doaj   +1 more source

Miscellaneous equalities for idempotent matrices with applications

open access: yesOpen Mathematics, 2020
This article brings together miscellaneous formulas and facts on matrix expressions that are composed by idempotent matrices in one place with cogent introduction and references for further study.
Tian Yongge
doaj   +1 more source

Characterizations of the group invertibility of a matrix revisited

open access: yesDemonstratio Mathematica, 2022
A square complex matrix AA is said to be group invertible if there exists a matrix XX such that AXA=AAXA=A, XAX=XXAX=X, and AX=XAAX=XA hold, and such a matrix XX is called the group inverse of AA.
Tian Yongge
doaj   +1 more source

Enumeration of some matrices and free linear codes over commutative finite local rings

open access: yesSpecial Matrices, 2021
Let R be a commutative finite local ring. Two enumeration problems over R are presented. We enumerate the matrices over R with a given McCoy rank and a given number of rows of single unit, and the free linear codes over R which have a given rank and a ...
Sirisuk Siripong
doaj   +1 more source

Combinatorial properties of the enhanced principal rank characteristic sequence over finite fields

open access: yesSpecial Matrices, 2021
The enhanced principal rank characteristic sequence (epr-sequence) of a symmetric matrix B ∈ 𝔽n×n is defined as ℓ1ℓ2· · · ℓn, where ℓj ∈ {A, S, N} according to whether all, some but not all, or none of the principal minors of order j of B are nonzero ...
Dukes Peter J., Martínez-Rivera Xavier
doaj   +1 more source

Group inverse of finite potent endomorphisms on arbitrary vector spaces

open access: yes, 2020
The aim of this work is to introduce the group inverse of a finite potent endomorphism on an infinite-dimensional vector space that generalizes the notion of group inverse of a square finite matrix. The existence and uniqueness of this inverse is proved,
F. P. Romo
semanticscholar   +1 more source

Searching for degenerate Higgs bosons - A profile likelihood ratio method to test for mass-degenerate states in the presence of incomplete data and uncertainties [PDF]

open access: yes, 2014
Using the likelihood ratio test statistic, we present a method which can be employed to test the hypothesis of a single Higgs boson using the matrix of measured signal strengths.
David, André   +2 more
core   +2 more sources

On mixed-type reverse-order laws for the Moore-Penrose inverse of a matrix product

open access: yesInternational Journal of Mathematics and Mathematical Sciences, 2004
Some mixed-type reverse-order laws for the Moore-Penrose inverse of a matrix product are established. Necessary and sufficient conditions for these laws to hold are found by the matrix rank method.
Yongge Tian
semanticscholar   +1 more source

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