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The minus order and range additivity
(Elsevier Science Inc, 2017-10)
We study the minus order on the algebra of bounded linear operators on a Hilbert space. By giving a characterization in terms of range additivity, we show that the intrinsic nature of the minus order is algebraic. Applications ...
Shorted operators and minus order
(Taylor & Francis Ltd, 2019-11)
Let H be a Hilbert space, L(H) the algebra of bounded linear operators on H and W ∈ L(H) a positive operator. Given a closed subspace S of H, we characterize the shorted operator W/S of W to S as the maximum and as the ...
Optimal Quasi-diagonal Preconditioners for Pseudodifferential Operators of Order Minus Two
(2019)
We present quasi-diagonal preconditioners for piecewise polynomial discretizations of pseudodifferential operators of order minus two in any space dimension. Here, quasi-diagonal means diagonal up to a sparse transformation. ...
Optimal Quasi-diagonal Preconditioners for Pseudodifferential Operators of Order Minus Two
(2019)
We present quasi-diagonal preconditioners for piecewise polynomial discretizations of pseudodifferential operators of order minus two in any space dimension. Here, quasi-diagonal means diagonal up to a sparse transformation. ...
On complementable operators in the sense of T. Ando
(Elsevier Science Inc, 2020-06)
Consider an operator A :H→K between Hilbert spaces and closed subspaces S ⊂ H and T ⊂ K. If there exist projections E on H and F on K such that R(E) =S, R(F) =T and AE=F∗A then A is called (S, T)-complementable. The origin ...
Solving an open problem about the G-Drazin partial order
(International Linear Algebra Society, 2020-02-08)
G-Drazin inverses and the G-Drazin partial order for square matrices have been both recently introduced by Wang and Liu. They proved the following implication: If A is below B under the G-Drazin partial order, then any ...
Efeito de deficiência de micronutrientes no estado nutricional da mamoneira cultivar Iris
(Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA), 2005-01-01)
Os objetivos deste trabalho foram caracterizar os sintomas visuais de deficiência de micronutrientes e avaliar efeitos desses micronutrientes no estado nutricional da mamoeira. O experimento foi realizado em casa de vegetação ...
Efeito de deficiência de micronutrientes no estado nutricional da mamoneira cultivar Iris
(Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA), 2005-01-01)
Os objetivos deste trabalho foram caracterizar os sintomas visuais de deficiência de micronutrientes e avaliar efeitos desses micronutrientes no estado nutricional da mamoeira. O experimento foi realizado em casa de vegetação ...