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Related papers: A note on real operator monotone functions

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Let $n \in \N$ and $M_n$ be the algebra of $n \times n$ matrices. We call a function $f$ matrix monotone of order $n$ or $n$-monotone in short whenever the inequality $f(a) \leq f(b)$ holds for every pair of selfadjoint matrices $a, b \in…

Operator Algebras · Mathematics 2008-05-15 Hiroyuki Osaka , Jun Tomiyama

We present some results on the monotonicity of some traces involving functions of self-adjoint operators with respect to the natural ordering of their associated quadratic forms. We also apply these results to complete a proof of the Wegner…

Functional Analysis · Mathematics 2016-09-14 J. -M. Combes , P. D. Hislop

In this paper, we characterize all closed linear operators in a separable Hilbert space which are unitarily equivalent to an integral bi-Carleman operator in $L_2(R)$ with bounded and arbitrarily smooth kernel on $R^2$. In addition, we give…

Spectral Theory · Mathematics 2007-05-23 Igor M. Novitskii

Our main theorem is in the generality of the axioms of Hilbert space, and the theory of unbounded operators. Consider two Hilbert spaces such that their intersection contains a fixed vector space D. It is of interest to make a precise…

Functional Analysis · Mathematics 2017-01-19 Palle Jorgensen , Erin Pearse , Feng Tian

Monotone operators are of central importance in modern optimization and nonlinear analysis. Their study has been revolutionized lately, due to the systematic use of the Fitzpatrick function. Pioneered by Penot and Svaiter, a topic of recent…

Functional Analysis · Mathematics 2008-02-12 Heinz H. Bauschke , Xianfu Wang , Liangjin Yao

In this article we study different aspects of Hermitian operators applying the concept of positive decompositions. On the one hand, we characterize the positivity of an Hermitian operator by means of a norm condition where the factors of…

Functional Analysis · Mathematics 2024-12-31 Guillermina Fongi , María Celeste Gonzalez

The theory of positive kernels and associated reproducing kernel Hilbert spaces, especially in the setting of holomorphic functions, has been an important tool for the last several decades in a number of areas of complex analysis and…

Operator Algebras · Mathematics 2016-02-03 Joseph A. Ball , Gregory Marx , Victor Vinnikov

We introduce a framework based on Rockafellar's perturbation theory to analyze and solve general nonsmooth convex minimization and monotone inclusion problems involving nonlinearly composed functions as well as linear compositions. Such…

Optimization and Control · Mathematics 2023-06-23 Luis M. Briceño-Arias , Patrick L. Combettes

We prove a nonsmooth implicit function theorem applicable to the zero set of the difference of convex functions. This theorem is explicit and global: it gives a formula representing this zero set as a difference of convex functions which…

Analysis of PDEs · Mathematics 2021-02-25 Jun Kitagawa , Robert McCann

We consider the space of convex functions defined in the Euclidean $n$-dimensional space, which are lower semi-continuous and tend to infinity at infinity. We study real-valued valuations defined on this space of functions, which are…

Metric Geometry · Mathematics 2015-08-04 L. Cavallina , A. Colesanti

Let B(H) be the algebra of all bounded linear operators on a Hilbert space H. The main goal of the paper is to find large classes of noncommutative domains in B(H) with prescribed universal operator models, acting on the full Fock space…

Functional Analysis · Mathematics 2024-04-16 Gelu Popescu

We study finitely cyclic self-adjoint operators in a Hilbert space, i.e. self-adjoint operators that posses such a finite subset in the domain that the orbits of all its elements with respect to the operator are linearly dense in the space.…

Spectral Theory · Mathematics 2022-12-29 Marcin Moszyński

A commuting $n$-tuple $(T_1, \ldots, T_n)$ of bounded linear operators on a Hilbert space $\clh$ associate a Hilbert module $\mathcal{H}$ over $\mathbb{C}[z_1, \ldots, z_n]$ in the following sense: \[\mathbb{C}[z_1, \ldots, z_n] \times…

Functional Analysis · Mathematics 2014-09-30 Jaydeb Sarkar

The characteristic function has been an important tool for studying completely non unitary contractions on Hilbert spaces. In this note, we consider completely non-coisometric contractive tuples of commuting operators on a Hilbert space…

Operator Algebras · Mathematics 2007-05-23 T. Bhattacharyya , J. Eschmeier , J. Sarkar

If a differential operator $D$ on a smooth Hermitian vector bundle $S$ over a compact manifold $M$ is symmetric, it is essentially self-adjoint and so admits the use of functional calculus. If $D$ is also elliptic, then the Hilbert space of…

K-Theory and Homology · Mathematics 2020-05-13 Anna Duwenig

We define a smooth functional calculus for a non-commuting tuple of (unbounded) operators $A_j$ on a Banach space with real spectra and resolvents with temperate growth, by means of an iterated Cauchy formula. The construction is also…

Spectral Theory · Mathematics 2007-05-23 Mats Andersson , Johannes Sjoestrand

Functional analysis, especially the theory of Hilbert spaces and of operators on these, form an important area in mathematics. We formalized the Isabelle/HOL library Complex_Bounded_Operators containing a large amount of theorems about…

Logic in Computer Science · Computer Science 2025-12-08 Dominique Unruh , José Manuel Rodríguez Caballero

Operator systems are the unital self-adjoint subspaces of the bounded operators on a Hilbert space. Complex operator systems are an important category containing the C*-algebras and von Neumann algebras, which is increasingly of interest in…

Operator Algebras · Mathematics 2025-10-07 David P. Blecher , Travis B. Russell

Let T and C be two Hilbert space operators. We prove that if T is near, in a certain sense, to an operator completely polynomially dominated with a finite bound by C, then T is similar to an operator which is completely polynomially…

Functional Analysis · Mathematics 2007-05-23 C. Badea

Using diagrammatic techniques, we provide explicit functional relations between the cumulant generating functions for the biunitarily invariant ensembles in the limit of large size of matrices. The formalism allows to map two distinct areas…

Mathematical Physics · Physics 2017-10-25 Maciej A. Nowak , Wojciech Tarnowski