Results 11 to 20 of about 220,336 (311)
On the Positive Operator Solutions to an Operator Equation X−A∗X−tA=Q
Journal of Mathematics, 2021 In this paper, the positive operator solutions to operator equation X−A∗X−tA=Q (t > 1) are studied in infinite dimensional Hilbert space. Firstly, the range of norm and the spectral radius of the solution to the equation are given.
Kaifan Yang
doaj +2 more sources
Positive Solutions of Operator Equations AX = B, XC = D
Axioms, 2023 In this paper, using the technique of operator matrix, we consider the positive solution of the system of operator equations AX=B,XC=D in the framework of the Hilbert space; here, the ranges R(A) of A and R(C) of C are not necessarily closed. Firstly, we
Haiyan Zhang, Yanni Dou, Weiyan Yu
doaj +2 more sources
Positive-Operator Valued Measure (POVM) Quantization
Axioms, 2014 We present a general formalism for giving a measure space paired with a separable Hilbert space a quantum version based on a normalized positive operator-valued measure.
Jean Pierre Gazeau, Barbara Heller
doaj +2 more sources
Inequalities and Reverse Inequalities for the Joint A-Numerical Radius of Operators
Axioms, 2023 In this paper, we aim to establish several estimates concerning the generalized Euclidean operator radius of d-tuples of A-bounded linear operators acting on a complex Hilbert space H, which leads to the special case of the well-known A-numerical radius ...
Najla Altwaijry +2 more
doaj +1 more source
Further Inequalities for the Weighted Numerical Radius of Operators
Mathematics, 2022 This paper deals with the so-called A-numerical radius associated with a positive (semi-definite) bounded linear operator A acting on a complex Hilbert space H. Several new inequalities involving this concept are established.
Najla Altwaijry +2 more
doaj +1 more source
Orthogonalization of Positive Operator Valued Measures
Comptes Rendus. Mathématique, 2022 We show that a partition of the unity (or POVM) on a Hilbert space that is almost orthogonal is close to an orthogonal POVM in the same von Neumann algebra. This generalizes to infinite dimension previous results in matrix algebras by Kempe–Vidick and Ji–
de la Salle, Mikael
doaj +1 more source
Algebraic reflexivity of isometry groups and automorphism groups of some operator structures [PDF]
, 2013 We establish the algebraic re exivity of three isometry groups of operator structures: The group of all surjective isometries on the unitary group, the group of all surjective isometries on the set of all positive invertible operators equipped with ...
Botelho, Fernanda +2 more
core +1 more source
On Some bounded Operators and their characterizations in Г-Hilbert Space
Cumhuriyet Science Journal, 2020 Some bounded operators are part of this paper.Through this paper we shall obtain common properties of Some bounded operators in Г-Hilbert space. Also, introduced 2-self-adjoint operators and it’s spectrum in Г-Hilbert Space.
Sahın Injamamul Islam
doaj +1 more source
Approximation of positive operators by analytic vectors
Karpatsʹkì Matematičnì Publìkacìï, 2020 We give the estimates of approximation errors while approximating of a positive operator $A$ in a Banach space by analytic vectors. Our main results are formulated in the form of Bernstein and Jackson type inequalities with explicitly calculated ...
M.I. Dmytryshyn
doaj +1 more source
Linear Fractional Transformations of Nevanlinna Functions Associated with a Nonnegative Operator [PDF]
, 2011 In the present paper a subclass of scalar Nevanlinna functions is studied, which coincides with the class of Weyl functions associated to a nonnegative symmetric operator of defect one in a Hilbert space.
Winkler, Henrik, +15 more
core +1 more source