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Related papers: Anti-norms on finite von Neumann algebras

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Some subadditivity results involving symmetric (unitarily invariant) norms are obtained. For instance, if $g(t)=\sum_{k=0}^m a_kt^k$ is a polynomial of degree $m$ with non-negative coefficients, then, for all positive operators $A,\,B$ and…

Functional Analysis · Mathematics 2011-02-08 Jean-Christophe Bourin , Fumio Hiai

We establish new metric characterizations for the norm (respectively, ultraweak) closure of the convex hull of a bounded set in an arbitrary $C^*$-algebra (respectively, von Neumann algebra), and provide applications of these results to the…

Operator Algebras · Mathematics 2024-05-29 Mikaël Pichot , Erik Séguin

Some rearrangement inequalities for symmetric norms on matrices are given as well as related results for operator convex functions.

Functional Analysis · Mathematics 2007-05-23 Jean-Christophe Bourin

Jensen inequalities for positive linear maps of Choi and Hansen-Pedersen type are established for a large class of operator/matrix means. These results are also extensions of the Minkowski determinantal inequality. To this end we develop…

Functional Analysis · Mathematics 2011-09-15 Jean-Christophe Bourin , Fumio Hiai

We introduce a notion of ``hereditarily antisymmetric'' operator algebras and prove a structure theorem for them in finite dimensions. We also characterize those operator algebras in finite dimensions which can be made upper triangular and…

Operator Algebras · Mathematics 2021-07-01 Nik Weaver

It is shown that the *-algebra of all (closed densely defined linear) operators affiliated with a finite type I von Neumann algebra admits a unique center-valued trace, which turns out to be, in a sense, normal. It is also demonstrated that…

Operator Algebras · Mathematics 2017-05-26 Piotr Niemiec , Adam Wegert

We characterize in terms of inequalities the possible generalized singular numbers of a product AB of operators A and B having given generalized singular numbers, in an arbitrary finite von Neumann algebra. We also solve the analogous…

Operator Algebras · Mathematics 2016-01-26 Hari Bercovici , Benoit Collins , Ken Dykema , Wing Suet Li

We look at explicit ways to bring one or two antiunitary symmetries into a standard form via unitary conjugation. We carefully reproduce Wigner's proof in two special cases, where the antiunitary operators square to $+I$, or to $-I$.…

Mathematical Physics · Physics 2025-08-22 Terry A. Loring

A new class of operators, larger than $C$-symmetric operators and different than normal one, named $C$--normal operators is introduced. Basic properties are given. Characterizations of this operators in finite dimensional spaces using a…

Functional Analysis · Mathematics 2020-01-01 Marek Ptak , Katarzyna Simik , Anna Wicher

Well-known subadditivity results for positive operators (of Brown-Kosaki and Rotfeld/Ando-Zhan types) are extended to Hermitian and normal ones. Applications to Cartesian decomposition and block-matrices are given.

Functional Analysis · Mathematics 2009-06-09 jean-Christophe Bourin

In this article we show that positive surjective isometries between symmetric spaces associated with semi-finite von Neumann algebras are projection disjointness preserving if they are finiteness preserving. This is subsequently used to…

Operator Algebras · Mathematics 2019-07-16 Pierre de Jager , Jurie Conradie

Changes of some unitarily invariant norms and anti-norms under the operation of partial trace are examined. The norms considered form a two-parametric family, including both the Ky Fan and Schatten norms as particular cases. The obtained…

Quantum Physics · Physics 2012-11-02 Alexey E. Rastegin

An antinorm is a concave nonnegative homogeneous functional on a convex cone. It is shown that if the cone is polyhedral, then every antinorm has a unique continuous extension from the interior of the cone. The main facts of the duality…

Metric Geometry · Mathematics 2021-09-27 Vladimir Yu. Protasov

This paper formulates Young-type inequalities for singular values (or $s$-numbers) and traces in the context of von Neumann algebras. In particular, it shown that if $\t(\cdot)$ is a faithful semifinite normal trace on a semifinite von…

Operator Algebras · Mathematics 2007-05-23 Douglas R. Farenick , S. Mahmoud Manjegani

Asymmetric vector norms are generalizations of asymmetric norms, where the subadditivity inequality is understood in ordered vector space sense. This relation imposes strong conditions on the ordering itself. This note studies on these…

Functional Analysis · Mathematics 2020-05-22 A. B. Németh , S. Z. Németh

We study a specific family of symmetric norms on the algebra $\mathcal B(\mathcal H)$ of operators on a separable infinite-dimensional Hilbert space. With respect to each symmetric norm in this family the identity operator fails to attain…

Functional Analysis · Mathematics 2020-09-24 Satish K. Pandey

We introduce the von Neumann entropy regularization of Unbalanced Non-commutative Optimal Transport, specifically Non-commutative Optimal Transport between semi-definite positive matrices (not necessarily with trace one). We prove the…

Optimization and Control · Mathematics 2024-02-28 Augusto Gerolin , Nataliia Monina

Let $A$ be a positive definite operator on a Hilbert space $H$, and $|||.|||$ be a unitarily invariant norm on $B(H)$. We show that if $f$ is an operator monotone function on $(0,\infty)$ and $n\in \mathbb{N}$, then $|||D^n…

Functional Analysis · Mathematics 2021-05-13 Amir Ghasem Ghazanfari

Different notions for order convergence have been considered by various authors. Associated to every notion of order convergence corresponds a topology, defined by taking as the closed sets those subsets of the poset satisfying that no net…

Functional Analysis · Mathematics 2020-12-29 Kevin Abela , Emmanuel Chetcuti , Hans Weber

We give an overview of the question: which positive elements in an operator algebra can be written as a linear combination of projections with positive coefficients. A special case of independent interest is the question of which positive…

Operator Algebras · Mathematics 2012-01-24 V. Kaftal , P. W. Ng , S. Zhang
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