AbstractLet A be an n×n real matrix, and K⊂Rn be a closed convex cone. The spectrum of A relative to K, denoted by σ(A,K), is the set of all λ∈R for which the linear complementarity problemx∈K,Ax−λx∈K+,〈x,Ax−λx〉=0admitsa nonzero solution x∈Rn. The notation K+ stands for the (positive) dual cone of K. The purpose of this work is to study the main properties of the mapping σ(·,K), and discuss some structural differences existing between the polyhedral case (i.e. K is finitely generated) and the nonpolyhedral case
AbstractIn this paper, we present a sharp version of Bauer–Fike’s theorem. We replace the matrix nor...
AbstractWe describe the set of all (α,n), for which the scalar complex matrix αIn is a sum of k idem...
AbstractIn this paper the numerical range of operators (possibly unbounded) in an indefinite inner p...
AbstractLet A be a normal matrix and consider the polygon NR[A]={x*Ax:∥x∥=1}. If υ*Aυ∈intNR[A], a pr...
AbstractThe domain D(δ2) of the square of a closed ∗-derivation δ in C(K) (K is a compact Hausdorff ...
Let E be a Banach space on a set X and M(E) the space of multipliers of E. In this paper, we study t...
AbstractWe consider a distance-regular graph Γ with diameter D≥ 3, intersection numbers ai, bi, cian...
AbstractIn this paper, we characterize some operators and matrix transformations in the sequence spa...
AbstractLet Mn be the space of all n×n complex matrices, and let Γn be the subset of Mn consisting o...
AbstractWe present explicit formulae which allow us to construct elliptic matrices with zero diagona...
AbstractWe present, for every integer k∈N, an elementary construction of a contractible k-dimensiona...
AbstractLet Ω be an open, bounded domain in R2 with connected and C∞ boundary, and ω a solution of(0...
AbstractIf k⩽n, then Gk,n denotes the set of all strictly increasing functions from {1,2,…,k} to {1,...
AbstractLet λ denote any of the classical spaces ℓ∞,c,c0, and ℓp of bounded, convergent, null, and a...
AbstractLet λ denote any one of the classical spaces ℓ∞, c, c0 and ℓp of bounded, convergent, null a...
AbstractIn this paper, we present a sharp version of Bauer–Fike’s theorem. We replace the matrix nor...
AbstractWe describe the set of all (α,n), for which the scalar complex matrix αIn is a sum of k idem...
AbstractIn this paper the numerical range of operators (possibly unbounded) in an indefinite inner p...
AbstractLet A be a normal matrix and consider the polygon NR[A]={x*Ax:∥x∥=1}. If υ*Aυ∈intNR[A], a pr...
AbstractThe domain D(δ2) of the square of a closed ∗-derivation δ in C(K) (K is a compact Hausdorff ...
Let E be a Banach space on a set X and M(E) the space of multipliers of E. In this paper, we study t...
AbstractWe consider a distance-regular graph Γ with diameter D≥ 3, intersection numbers ai, bi, cian...
AbstractIn this paper, we characterize some operators and matrix transformations in the sequence spa...
AbstractLet Mn be the space of all n×n complex matrices, and let Γn be the subset of Mn consisting o...
AbstractWe present explicit formulae which allow us to construct elliptic matrices with zero diagona...
AbstractWe present, for every integer k∈N, an elementary construction of a contractible k-dimensiona...
AbstractLet Ω be an open, bounded domain in R2 with connected and C∞ boundary, and ω a solution of(0...
AbstractIf k⩽n, then Gk,n denotes the set of all strictly increasing functions from {1,2,…,k} to {1,...
AbstractLet λ denote any of the classical spaces ℓ∞,c,c0, and ℓp of bounded, convergent, null, and a...
AbstractLet λ denote any one of the classical spaces ℓ∞, c, c0 and ℓp of bounded, convergent, null a...
AbstractIn this paper, we present a sharp version of Bauer–Fike’s theorem. We replace the matrix nor...
AbstractWe describe the set of all (α,n), for which the scalar complex matrix αIn is a sum of k idem...
AbstractIn this paper the numerical range of operators (possibly unbounded) in an indefinite inner p...