Generalized concentrative mappings and their fixed points
Josef Daneš (1970)
Commentationes Mathematicae Universitatis Carolinae
Mecheri, Salah, Bachir, Ahmed (2002)
International Journal of Mathematics and Mathematical Sciences
Yan, Dangui, Zhang, Chengchang (2011)
International Journal of Mathematics and Mathematical Sciences
Mecheri, Salah (2009)
Analele Ştiinţifice ale Universităţii “Ovidius" Constanţa. Seria: Matematică
Mecheri, Salah (2009)
International Journal of Open Problems in Computer Science and Mathematics. IJOPCM
Barraa, Mohamed (2011)
Serdica Mathematical Journal
2000 Mathematics Subject Classification: 47A10, 47A12, 47A30, 47B10, 47B20, 47B37, 47B47, 47D50.We compare the norm of a generalized derivation on a Hilbert space with the norm of its restrictions to Schatten norm ideals.
Jiankui Li, Jiren Zhou (2010)
Czechoslovak Mathematical Journal
We investigate a new type of generalized derivations associated with Hochschild 2-cocycles which was introduced by A. Nakajima. We show that every generalized Jordan derivation of this type from CSL algebras or von Neumann algebras into themselves is a generalized derivation under some reasonable conditions. We also study generalized derivable mappings at zero point associated with Hochschild 2-cocycles on CSL algebras.
Basudeb Dhara, Sukhendu Kar, Sachhidananda Mondal (2015)
Czechoslovak Mathematical Journal
Let be a prime ring with its Utumi ring of quotients and extended centroid . Suppose that is a generalized derivation of and is a noncentral Lie ideal of such that for all , where is a fixed integer. Then one of the following holds:
Feng Wei, Zhankui Xiao (2009)
Rendiconti del Seminario Matematico della Università di Padova
Bouali, S., Ech-chad, M. (2008)
Serdica Mathematical Journal
2000 Mathematics Subject Classification: Primary: 47B47, 47B10; secondary 47A30.Let H be an infinite-dimensional complex Hilbert space and let A, B ∈ L(H), where L(H) is the algebra of operators on H into itself. Let δAB: L(H) → L(H) denote the generalized derivation δAB(X) = AX − XB. This note will initiate a study on the class of pairs (A,B) such that [‾(R(δAB))] = [‾(R(δB*A*))]; i.e. [‾(R(δAB))] is self-adjoint.
Mihai Putinar (1997)
Banach Center Publications
The paper relates several generalized eigenfunction expansions to classical spectral decomposition properties. From this perspective one explains some recent results concerning the classes of decomposable and generalized scalar operators. In particular a universal dilation theory and two different functional models for related classes of operators are presented.
V. Khatskevich (1999)
Studia Mathematica
The convexity and compactness in the weak operator topology of the image and pre-image of a generalized fractional linear transformation is established. As an application the exponential dichotomy of solutions to evolution problems of the parabolic type is proved.
Constantinescu, Florin, Scharf, Günter (1998)
Journal of Inequalities and Applications [electronic only]
Chen, Tieling, Sinnamon, Gord (2002)
Journal of Inequalities and Applications [electronic only]
David Borwein (1983)
Mathematische Zeitschrift
Sunanda Naik, Karabi Rajbangshi (2015)
Bulletin of the Polish Academy of Sciences. Mathematics
Let f be an analytic function on the unit disk . We define a generalized Hilbert-type operator by , where a and b are non-negative real numbers. In particular, for a = b = β, becomes the generalized Hilbert operator , and β = 0 gives the classical Hilbert operator . In this article, we find conditions on a and b such that is bounded on Dirichlet-type spaces , 0 < p < 2, and on Bergman spaces , 2 < p < ∞. Also we find an upper bound for the norm of the operator . These generalize...
Gordji, M.Eshaghi, Rassias, J.M., Ghobadipour, N. (2009)
Abstract and Applied Analysis
Asia Majieed, Jiren Zhou (2010)
Czechoslovak Mathematical Journal
In this paper, we investigate a new type of generalized derivations associated with Hochschild 2-cocycles which is introduced by A.Nakajima (Turk. J. Math. 30 (2006), 403–411). We show that if is a triangular algebra, then every generalized Jordan derivation of above type from into itself is a generalized derivation.
Antonio Manzano, Mieczyslaw Mastylo (2007)
Collectanea Mathematica
We establish results on interpolation of Rosenthal operators, Banach-Saks operators, Asplund operators and weakly compact operators by means of generalized Lions-Peetre methods of constants and means. Applications are presented for the K-method space generated by the Calderón-Lozanovskii space parameters.
Khalid Souilah (2022)
Mathematica Bohemica
We provide a complete description of the perturbation class and the commuting perturbation class of all generalized quadratic bounded operators with respect to a given idempotent bounded operator in the context of complex Banach spaces. Furthermore, we give simple characterizations of the generalized quadraticity of linear combinations of two generalized quadratic bounded operators with respect to a given idempotent bounded operator.