Results 41 to 50 of about 1,504,261 (185)
New multiplicativity results for qubit maps
, 2006 Let $\Phi$ be a trace-preserving, positivity-preserving (but not necessarily completely positive) linear map on the algebra of complex $2 \times 2$ matrices, and let $\Omega$ be any finite-dimensional completely positive map. For $p=2$ and $p \geq 4$, we
Amosov G. G. +4 more
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Population-only decay map for n-qubit n-partite inseparability detection [PDF]
, 2006 We introduce a new positive linear map for a single qubit. This map is a decay only in populations of a single-qubit density operator. It is shown that an n-fold product of this map may be used for a detection of n-partite inseparability of an n-qubit ...
Akira SaiToh +4 more
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A Grüss inequality for n-positive linear maps
Linear Algebra and its Applications, 2010 Let $\mathscr{A}$ be a unital $C^*$-algebra and let $ : \mathscr{A} \to {\mathbb B}({\mathscr H})$ be a unital $n$-positive linear map between $C^*$-algebras for some $n \geq 3$. We show that $$\| (AB)- (A) (B)\| \leq (A,||\cdot||)\, (B,||\cdot||)$$ for all operators $A, B \in \mathscr{A}$, where $ (C,\|\cdot\|)$ denotes the operator norm ...
Moslehian, Mohammad Sal, Rajić, Rajna
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Weighted arithmetic–geometric operator mean inequalities
Journal of Inequalities and Applications, 2018 In this paper, we refine and generalize some weighted arithmetic–geometric operator mean inequalities due to Lin (Stud. Math. 215:187–194, 2013) and Zhang (Banach J. Math. Anal. 9:166–172, 2015) as follows: Let A and B be positive operators.
Jianming Xue
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Positive Maps and Separable Matrices
, 2016 A linear map between real symmetric matrix spaces is positive if all positive semidefinite matrices are mapped to positive semidefinite ones. A real symmetric matrix is separable if it can be written as a summation of Kronecker products of positive ...
Nie, Jiawang, Zhang, Xinzhen
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Conditional Expectations for Unbounded Operator Algebras
International Journal of Mathematics and Mathematical Sciences, 2007 Two conditional expectations in unbounded operator algebras (O∗-algebras) are discussed. One is a vector conditional expectation defined by a linear map of an O∗-algebra into the Hilbert space on which the O∗-algebra acts.
Atsushi Inoue +2 more
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Characterization of the order relation on the set of completely n-positive linear maps between C*-algebras [PDF]
Surveys in Mathematics and its Applications, 2007 In this paper we characterize the order relation on the set of all nondegenerate completely n-positive linear maps between C*-algebras in terms of a self-dual Hilbert module induced by each completely n-positive linear map.
Maria Joita +2 more
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Operator upper bounds for Davis-Choi-Jensen's difference in Hilbert spaces [PDF]
Mathematica MoravicaIn this paper we obtain several operator inequalities providing upper bounds for the Davis-Choi-Jensen's Difference Ph (f (A)) - f (Ph (A)) for any convex function f : I → R, any selfadjoint operator A in H with the spectrum Sp (A) ⊂ I and any linear ...
Dragomir Silvestru Sever
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Entanglement Witnesses Arising from Exposed Positive Linear Maps [PDF]
Open Systems & Information Dynamics, 2011 We consider entanglement witnesses arising from positive linear maps which generate exposed extremal rays. We show that every entangled state can be detected by one of these witnesses, and this witness detects a unique set of entangled states among those. Therefore, they provide a minimal set of witnesses to detect any kind of entanglement in a sense.
Ha, Kil-Chan, Kye, Seung-Hyeok
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Visualizing extremal positive maps in unital and trace preserving form
, 2015 We define an entanglement witness in a composite quantum system as an observable having nonnegative expectation value in every separable state. Then a state is entangled if and only if it has a negative expectation value of some entanglement witness ...
Hansen, Leif Ove, Myrheim, Jan
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