Results 31 to 40 of about 572 (50)

The Nullity Theorem for Principal Pivot Transform

open access: yes, 2013
We generalize the nullity theorem of Gustafson [Linear Algebra Appl. (1984)] from matrix inversion to principal pivot transform. Several special cases of the obtained result are known in the literature, such as a result concerning local complementation ...
Brijder, Robert
core   +1 more source

Lineability and modes of convergence [PDF]

open access: yes, 2020
In this paper we look for the existence of large linear and algebraic structures of sequences of measurable functions with different modes of convergence. Concretely, the algebraic size of the family of sequences that are convergent in measure but not a.
Calderón Moreno, María del Carmen   +2 more
core  

Possible numbers of x’s in an {x, y}-matrix with a given rank

open access: yesOpen Mathematics, 2017
Let x, y be two distinct real numbers. An {x, y}-matrix is a matrix whose entries are either x or y. We determine the possible numbers of x’s in an {x, y}-matrix with a given rank. Our proof is constructive.
Ma Chao
doaj   +1 more source

On the Principal Permanent Rank Characteristic Sequences of Graphs and Digraphs

open access: yes, 2015
The principal permanent rank characteristic sequence is a binary sequence $r_0 r_1 \ldots r_n$ where $r_k = 1$ if there exists a principal square submatrix of size $k$ with nonzero permanent and $r_k = 0$ otherwise, and $r_0 = 1$ if there is a zero ...
Horn, Paul   +5 more
core   +1 more source

Bilinear characterizations of companion matrices

open access: yesSpecial Matrices, 2014
Companion matrices of the second type are characterized by properties that involve bilinear maps.
Lin Minghua, Wimmer Harald K.
doaj   +1 more source

Minor-closed classes of binary functions [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science
Binary functions are a generalisation of the cocircuit spaces of binary matroids to arbitrary functions. Every rank function is assigned a binary function, and the deletion and contraction operations of binary functions generalise matroid deletion and ...
Benjamin R. Jones
doaj   +1 more source

On relationships between two linear subspaces and two orthogonal projectors

open access: yesSpecial Matrices, 2019
Sum and intersection of linear subspaces in a vector space over a field are fundamental operations in linear algebra. The purpose of this survey paper is to give a comprehensive approach to the sums and intersections of two linear subspaces and their ...
Tian Yongge
doaj   +1 more source

Counting Semilinear Endomorphisms Over Finite Fields [PDF]

open access: yes, 2011
For a finite field k and a triple of integers g \ge r \ge s \ge 0, we count the number of semilinear endomorphisms of a g-dimensional k-vector space which have rank r and stable rank s. Such endomorphisms show up naturally in the classification of finite
Holland, Timothy
core  

Families of graphs with maximum nullity equal to zero forcing number

open access: yesSpecial Matrices, 2018
The maximum nullity of a simple graph G, denoted M(G), is the largest possible nullity over all symmetric real matrices whose ijth entry is nonzero exactly when fi, jg is an edge in G for i =6 j, and the iith entry is any real number.
Alameda Joseph S.   +7 more
doaj   +1 more source

Singular matrices possessing the triangle property

open access: yesSpecial Matrices
It is known that the inverse of an invertible real square matrix satisfying the triangle property is a tridiagonal matrix. In this note, results that may be considered as analogues of this assertion are obtained for the Moore-Penrose inverse and the ...
Priya K. Kranthi, Sivakumar K. C.
doaj   +1 more source

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