


Paper's Title:
ANormal Operators In Semi Hilbertian Spaces
Author(s):
A. Saddi
Department of Mathematics,
College of Education for Girls in Sarat Ebeidah 61914, Abha,
King Khalid University
Saudi Arabia
adel.saddi@fsg.rnu.tn
Abstract:
In this paper we study some properties and inequalities of Anormal operators in semiHilbertian spaces by employing some known results for vectors in inner product spaces. We generalize also most of the inequalities of (α,β)normal operators discussed in Hilbert spaces [7].
Paper's Title:
Hyponormal and KQuasiHyponormal Operators On SemiHilbertian Spaces
Author(s):
Ould Ahmed Mahmoud Sid Ahmed and Abdelkader Benali
Mathematics Department,
College of Science,
Aljouf University,
Aljouf 2014,
Saudi Arabia.
Email:
sididahmed@ju.edu.sa
Mathematics Department, Faculty of
Science,
Hassiba Benbouali, University of Chlef,
B.P. 151 Hay Essalem, Chlef 02000,
Algeria.
Email:
benali4848@gmail.com
Abstract:
Let H be a Hilbert space and let A be a positive bounded operator on H. The semiinner product < uv>_{A}:=<Auv>, u,v ∈ H induces a seminorm  ._{A} on H. This makes H into a semiHilbertian space. In this paper we introduce the notions of hyponormalities and kquasihyponormalities for operators on semi Hilbertian space (H,._{A}), based on the works that studied normal, isometry, unitary and partial isometries operators in these spaces. Also, we generalize some results which are already known for hyponormal and quasihyponormal operators. An operator T ∈ B_{A} (H) is said to be (A, k)quasihyponormal if
Paper's Title:
ψ(m,q)Isometric Mappings on Metric Spaces
Author(s):
Sid Ahmed Ould Beinane, Sidi Hamidou Jah and Sid Ahmed Ould Ahmed Mahmoud
Mathematical Analysis and Applications,
Mathematics Department, College of Science,
Jouf University,
Sakaka P.O.Box 2014,
Saudi Arabia.
Email: beinane06@gmail.com
Department of Mathematics, College of
Science Qassim University,
P.O. Box 6640, Buraydah 51452,
Saudi Arabia.
Email: jahsiidi@yahoo.fr
Mathematical Analysis and Applications,
Mathematics Department, College of Science, Jouf University,
Sakaka P.O.Box 2014,
Saudi Arabia.
Email: sidahmed@ju.edu.sa,
sidahmed.sidha@gmail.com
Abstract:
The concept of (m,p)isometric operators on Banach space was extended to
(m,q)isometric mappings on general metric spaces in [6].
This paper is devoted to define the concept of
ψ(m, q)isometric, which is the
extension of A(m, p)isometric operators on Banach spaces introduced in [10].
Let T,ψ: (E,d) > (E, d) be two mappings.
For some positive integer m and q ∈ (0,∞).
T is said to be an ψ(m,q)isometry,
if for all y,z ∈ E,
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