Results 31 to 40 of about 458,761 (298)

Pinchings and positive linear maps

Journal of Functional Analysis, 2016
We employ the pinching theorem, ensuring that some operators A admit any sequence of contractions as an operator diagonal of A, to deduce/improve two recent theorems of Kennedy-Skoufranis and Loreaux-Weiss for conditional expectations onto a masa in the algebra of operators on a Hilbert space. We also get a few results for sums in a unitary orbit.
Bourin, Jean-Christophe, Lee, Eun-Young
openaire   +3 more sources

On the Debate Concerning the Proper Characterisation of Quantum Dynamical Evolution [PDF]

, 2012
There has been a long-standing and sometimes passionate debate between physicists over whether a dynamical framework for quantum systems should incorporate not completely positive (NCP) maps in addition to completely positive (CP) maps.
Cuffaro, Michael E., Michael E. Cuffaro, Myrvold, Wayne C., Wayne C. Myrvold   +3 more
core   +1 more source

Some refinements of operator reverse AM-GM mean inequalities

Journal of Inequalities and Applications, 2017
In this paper, we prove the operator inequalities as follows: Let A , B $A,B$ be positive operators on a Hilbert space with 0 < m ≤ A , B ≤ M $0 < m \le A,B \le M$ and M m ≤ 2.314 $\sqrt{\frac{M}{m}} \le2.314$ .
Jianming Xue
doaj   +1 more source

On the Russo-Dye Theorem for positive linear maps [PDF]

Linear Algebra and its Applications, 2019
We revisit a classical result, the Russo-Dye Theorem, stating that every positive linear map attains its norm at the identity.
Bourin, Jean-Christophe, Lee, Eun-Young
openaire   +4 more sources

Some reverse mean inequalities for operators and matrices

Journal of Inequalities and Applications, 2019
In this paper, we present some new reverse arithmetic–geometric mean inequalities for operators and matrices due to Lin (Stud. Math. 215:187–194, 2013).
Chaojun Yang, Yaxin Gao, Fangyan Lu
doaj   +1 more source

A Grüss inequality for n-positive linear maps

Linear Algebra and its Applications, 2010
7 pages; to appear in Linear Algebra Appl. (LAA)
Moslehian, Mohammad Sal, Rajić, Rajna
openaire   +4 more sources

Some Fixed Point Properties of Self-Maps Constructed by Switched Sets of Primary Self-Maps on Normed Linear Spaces

Fixed Point Theory and Applications, 2010
This paper is devoted to the investigation of the existence of fixed points in a normed linear space X endowed with a norm ‖⋅‖ for self-maps f from T×X to X which are constructed from a given class of so-called primary self ...
M. De la Sen
doaj   +2 more sources

Investigation of distinctive physico-chemical soil correlations for Kirkuk city using spatial analysis technique incorporated with statistical modeling

International Journal of Geo-Engineering, 2021
In the sense of challenging economic situation, it is difficult to perform laboratory tests in a whole intended area to define the soil characteristics for whatever task or situation within an entire city.
Aram Mohammed Raheem, Najat Qader Omar
doaj   +1 more source

A Class of Linear Positive Maps in Matrix Algebras [PDF]

Open Systems & Information Dynamics, 2003
A class of linear positive, trace preserving maps in Mn is given in terms of affine maps in ℝn2−1 which map the closed unit ball into itself.
openaire   +2 more sources

Positive linear maps on normal matrices [PDF]

International Journal of Mathematics, 2018
For a positive linear map [Formula: see text] and a normal matrix [Formula: see text], we show that [Formula: see text] is bounded by some simple linear combinations in the unitary orbit of [Formula: see text]. Several elegant sharp inequalities are derived, for instance for the Schur product of two normal matrices [Formula: see text], [Formula: see ...
Jean-Christophe Bourin, Eun-Young Lee
openaire   +3 more sources