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In this paper we focus on different -- global, semi-local and local -- versions of Hoffman type inequalities expressed in a variational form. In a first stage our analysis is developed for generic multifunctions between metric spaces and we…

Optimization and Control · Mathematics 2022-03-22 Jesús Camacho , María Josefa Cánovas , Juan Parra

We pursue the study of a model convex functional with orthotropic structure and nonstandard growth conditions, this time focusing on the sub-quadratic case. We prove that bounded local minimizers are locally Lipschitz. No restriction on the…

Analysis of PDEs · Mathematics 2022-11-15 Pierre Bousquet , Lorenzo Brasco , Chiara Leone

We characterize metric spaces whose Lipschitz free space is isometric to $\ell_1$. In particular, the Lipschitz free space over an ultrametric space is not isometric to $\ell_1(\Gamma)$ for any set $\Gamma$. We give a lower bound for the…

Functional Analysis · Mathematics 2016-09-13 Aude Dalet , Pedro L. Kaufmann , Antonín Procházka

We demonstrate that the matrix quantum group $SL_q(2)$ gives rise to nontrivial matrix product operator representations of the Lie group $SL(2)$, providing an explicit characterization of the nontrivial global $SU(2)$ symmetry of the XXZ…

Statistical Mechanics · Physics 2022-02-15 Romain Couvreur , Laurens Lootens , Frank Verstraete

This is a systematic study of isometries between noncommutative symmetric spaces. Let $\mathcal{M}$ be a semifinite von Neumann algebra (or an atomic von Neumann algebra with all atoms having the same trace) acting on a separable Hilbert…

Operator Algebras · Mathematics 2025-12-25 Kai Fang , Tianbao Guo , Jinghao Huang , Fedor Sukochev

We study the quantitative properties of Lipschitz mappings from Euclidean spaces into metric spaces. We prove that it is always possible to decompose the domain of such a mapping into pieces on which the mapping "behaves like a projection…

Metric Geometry · Mathematics 2020-05-14 Guy C. David , Raanan Schul

We show that on bounded Lipschitz pseudoconvex domains that admit good weight functions the $\overline{\partial}$-Neumann operators $N_q, \overline{\partial}^* N_{q}$, and $\overline{\partial} N_{q}$ are bounded on $L^p$ spaces for some…

Complex Variables · Mathematics 2018-01-22 Phillip S. Harrington , Yunus E. Zeytuncu

Given a Lipschitz map $f$ from a cube into a metric space, we find several equivalent conditions for $f$ to have a Lipschitz factorization through a metric tree. As an application we prove a recent conjecture of David and Schul. The…

Metric Geometry · Mathematics 2022-03-21 Behnam Esmayli , Piotr Hajłasz

We give an equivalent expression for the $K$-functional associated to the pair of operator spaces $(R,C)$ formed by the rows and columns respectively. This yields a description of the real interpolation spaces for the pair $(M_n(R),…

Operator Algebras · Mathematics 2014-12-23 Gilles Pisier

In our previous paper [SIMAX 31 n.3 1491-1506(2010)], we studied the condition metric in the space of maximal rank matrices. Here, we show that this condition metric induces a Lipschitz-Riemann structure on that space. After investigating…

Differential Geometry · Mathematics 2012-05-09 Carlos Beltrán , Jean-Pierre Dedieu , Gregorio Malajovich , Mike Shub

Motivated by noncommutative geometry and quantum physics, the concept of `metric operator field' is introduced. Roughly speaking, a metric operator field is a vector field on a set with values in self tensor product of a bundle of…

Operator Algebras · Mathematics 2019-07-31 Maysam Maysami Sadr

In this work we study the theoretical Lipschitz stability and propose a low-rank-assisted numerical method for the inverse medium scattering beyond the Born region. The proposed low-rank structure is based on the disk prolate spheroidal…

Numerical Analysis · Mathematics 2026-04-09 Shixu Meng

A powerful tool for studying geometrical problems in Hilbert space is developed. In particular, we study the quantum pure state tomography problem in finite dimensions from the point of view of dynamical systems and bifurcations theory.…

Quantum Physics · Physics 2015-12-02 D. Goyeneche , A. C. de la Torre

This paper deals with the possibility of transforming a weakly measurable function in a Hilbert space into a continuous frame by a metric operator, i.e., a strictly positive self-adjoint operator. A necessary condition is that the domain of…

Functional Analysis · Mathematics 2020-02-27 J-P. Antoine , R. Corso , C. Trapani

We give extensions of results on nonnegative matrix semigroups which deduce finiteness or boundedness of such semigroups from the corresponding local properties, e.g., from finiteness or boundedness of values of certain linear functionals…

Functional Analysis · Mathematics 2013-07-01 Roman Drnovšek , Heydar Radjavi

We study variational inequalities which are governed by a strongly monotone and Lipschitz continuous operator $F$ over a closed and convex set $S$. We assume that $S=C\cap A^{-1}(Q)$ is the nonempty solution set of a (multiple-set) split…

Optimization and Control · Mathematics 2019-08-21 Andrzej Cegielski , Aviv Gibali , Simeon Reich , Rafał Zalas

We study the Lipschitz continuity of pluriharmonic Bloch mappings in the unit ball $\mathbb{B}^n$ with respect to the Bergman metric. We apply this to obtain a sufficient condition such that the composition operator on the pluriharmonic…

Complex Variables · Mathematics 2025-09-03 Jie Huang , Suman Das , Antti Rasila

A Quasi Toeplitz (QT) matrix is a semi-infinite matrix of the kind $A=T(a)+E$ where $T(a)=(a_{j-i})_{i,j\in\mathbb Z^+}$, $E=(e_{i,j})_{i,j\in\mathbb Z^+}$ is compact and the norms $\lVert a\rVert_{\mathcal W} = \sum_{i\in\mathbb Z}|a_i|$…

Numerical Analysis · Mathematics 2018-06-14 Dario A. Bini , Stefano Massei , Leonardo Robol

This manuscript focuses on the $\mathcal{H}_\infty$ observer design for a class of nonlinear discrete systems under the presence of measurement noise or external disturbances. Two new Linear Matrix Inequality (LMI) conditions are developed…

Systems and Control · Electrical Eng. & Systems 2024-07-12 Shivaraj Mohite

Generalizing a recent result on lineability of sets of non-injective linear operators, we prove, for quite general linear spaces $A$ of maps from an arbitraty set to a sequence space, that, for every $0 \neq f \in A$, the subset of $A$ of…

Functional Analysis · Mathematics 2024-04-16 Mikaela Aires , Geraldo Botelho
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