Results 31 to 40 of about 97 (90)

Putnam‐Fuglede theorem and the range‐kernel orthogonality of derivations

International Journal of Mathematics and Mathematical Sciences, Volume 27, Issue 9, Page 573-582, 2001., 2001
Let ℬ(H) denote the algebra of operators on a Hilbert space H into itself. Let d = δ or Δ, where δAB : ℬ(H) → ℬ(H) is the generalized derivation δAB(S) = AS − SB and ΔAB : ℬ(H) → ℬ(H) is the elementary operator ΔAB(S) = ASB − S. Given A, B, S ∈ ℬ(H), we say that the pair (A, B) has the property PF(d(S)) if dAB(S) = 0 implies dA∗B∗(S)=0.
B. P. Duggal
wiley   +1 more source

On the Upper Bound of the Third Hankel Determinant for Certain Class of Analytic Functions Related with Exponential Function

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2022
In the present paper we introduce a new class of analytic functions f in the open unit disk normalized by f(0) = f′(0)−1 = 0, associated with exponential functions.
Breaz Daniel, Cătaş Adriana, Cotîrlă Luminiţa-Ioana   +2 more
doaj   +1 more source

Derivations of certain operator algebras

International Journal of Mathematics and Mathematical Sciences, Volume 24, Issue 5, Page 345-349, 2000., 2000
Let 𝒩 be a nest and let 𝒜 be a subalgebra of L(H) containing all rank one operators of alg 𝒩. We give several conditions under which any derivation δ from 𝒜 into L(H) must be inner. The conditions include (1) H− ≠ H, (2) 0+ ≠ 0, (3) there is a nontrivial projection in 𝒩 which is in 𝒜, and (4) δ is norm continuous. We also give some pplications.
Jiankui Li, Hemant Pendharkar
wiley   +1 more source

SOME RESULTS ON OPERATORS CONSISTENT IN INVERTIBILITY [PDF]

, 2018
In this paper, we investigate the conditions under which some classes of operators in a complex Hilbert space H are said to be consistent in invertibility.
Wabuya, Kikete, Stephen, Luketero
core   +1 more source

Absolute continuity and hyponormal operators

International Journal of Mathematics and Mathematical Sciences, Volume 4, Issue 2, Page 321-335, 1981., 1981
Let T be a completely hyponormal operator, with the rectangular representation T = A + iB, on a separable Hilbert space. If 0 is not an eigenvalue of T* then T also has a polar factorization T = UP, with U unitary. It is known that A, B and U are all absolutely continuous operators.
C. R. Putnam
wiley   +1 more source

On Quasi-invertibility and Quasi-similarity of Operators in Hilbert Space. [PDF]

, 2018
In this paper we show that if two operators A and B are quasi-invertible then AB and BA are also quasi-similar. We also show that if two operators and are isometric is consistent in invertibility under further hypothesis.
S.W., Luketero, S.K, Waihenya, D.W., Kikete   +2 more
core   +1 more source

On numerical solution of nonlinear parabolic multicomponent diffusion-reaction problems

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2021
This work continues our previous analysis concerning the numerical solution of the multi-component mass transfer equations. The present test problems are two-dimensional, parabolic, non-linear, diffusion- reaction equations. An implicit finite difference
Juncu Gh., Popa C., Sarbu Gh.
doaj   +1 more source

Derivations and Extensions in JC‐Algebras

International Journal of Mathematics and Mathematical Sciences, Volume 2025, Issue 1, 2025.
A well‐known result by Upmeier states that every derivation on a universally reversible JC‐algebra A⊆B(H)sa extends to the C∗‐algebra [A] generated by A in B(H). In this paper, we significantly strengthen this result by proving that every Jordan derivation on a universally reversible JC‐algebra A extends to ∗‐derivations on its universal enveloping ...
Fatmah B. Jamjoom, Doha A. Abulhamail, Armando Sánchez-Nungaray   +2 more
wiley   +1 more source

On Quasi-similarity of a product of Quasi-similar operators in Hilbert Spaces. [PDF]

, 2015
In this paper we investigate the conditions under which two operators A and B are quasi-similar implies AB and BA are also quasi-similar. It is herein shown that if A and B satisfy the Putnam-Fuglede property and are quasi-similar with the intertwining ...
S.W., Luketero, D.W., Kikete, J.K., Mile, J.M, Khalagai   +3 more
core   +1 more source

Poisson C*-algebra derivations in Poisson C*-algebras

Demonstratio Mathematica
In this study, we introduce the following additive functional equation:g(λu+v+2y)=λg(u)+g(v)+2g(y)g\left(\lambda u+v+2y)=\lambda g\left(u)+g\left(v)+2g(y) for all λ∈C\lambda \in {\mathbb{C}}, all unitary elements u,vu,v in a unital Poisson C*{C ...
Wang Yongqiao, Park Choonkil, Chang Yuan
doaj   +1 more source