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In this paper, we give a new completion for quasi-uniform spaces which generalizes the completion theories of Doitchinov [8] and Stoltenberg [20]. The presented completion theory is very well-behaved and extends the completion theory of…

General Topology · Mathematics 2020-09-02 Athanasios Andrikopoulos , Ioannis Gounaridis

In this article, we prove a weak type $(p,p)$ maximal inequality, $1<p<\infty$, for weighted averages of a positive Dunford-Schwarz operator $T$ acting on a noncommutative $L_p$-space associated to a semifinite von Neumann algebra…

Operator Algebras · Mathematics 2026-02-18 Morgan O'Brien

It is not usual to characterize an operator valued series via completeness of multiplier spaces. In this study, by using a series of bounded linear operators, we introduce the space $M^\infty_{R}\big(\sum_k T_k\big)$ of Riesz summability…

Functional Analysis · Mathematics 2021-02-18 Mahmut Karakuş , Ramazan Kama

We completely characterize smoothness of bounded linear operators between infinite dimensional real normed linear spaces, probably for the very first time, by applying the concepts of Birkhoff-James orthogonality and semi-inner-products in…

Functional Analysis · Mathematics 2024-08-13 Debmalya Sain , Kallol Paul , Arpita Mal , Anubhab Ray

We prove a Liouville type classification theorem in half-spaces for infinite boundary value problems related to fully nonlinear, uniformly elliptic operators. We then apply the result in order to obtain gradient boundary blow up rates for…

Analysis of PDEs · Mathematics 2019-11-07 Isabeau Birindelli , Francoise Demengel , Fabiana Leoni

The nonlinear geometry of operator spaces has recently started to be investigated. Many notions of nonlinear embeddability have been introduced so far, but, as noticed before by other authors, it was not clear whether they could be…

Functional Analysis · Mathematics 2022-11-23 Bruno de Mendonça Braga , Timur Oikhberg

We extend the classical Fuglede commutativity theorem to the full scale of symmetrically normed operator ideals. Our main result provides a complete characterization: a symmetric ideal or symmetric operator space of $\tau$-measurable…

Functional Analysis · Mathematics 2025-12-17 Denis Potapov , Fedor Sukochev , Anna Tomskova , Dmitriy Zanin

We derive sufficient conditions for the surjectivity of the Cauchy-Riemann operator $\overline{\partial}$ between spaces of weighted smooth Fr\'echet-valued functions. This is done by establishing an analog of H\"ormander's theorem on the…

Functional Analysis · Mathematics 2022-10-27 Karsten Kruse

A metric space M is homogeneous if every isometry between finite subsets extends to a surjective isometry defined on the whole space. We show that if M is an ultrametric space, it suffices that isometries defined on singletons extend, i.e…

General Topology · Mathematics 2016-11-30 C. Delhomme , C. Laflamme , M. Pouzet , N. Sauer

We propose a new strong Riemannian metric on the manifold of (parametrized) embedded curves of regularity $H^s$, $s\in(3/2,2)$. We highlight its close relationship to the (generalized) tangent-point energies and employ it to show that this…

Differential Geometry · Mathematics 2025-12-17 Elias Döhrer , Philipp Reiter , Henrik Schumacher

Let $\mathcal{M}$ be a semifinite von Neumann algebra with a faithful, normal, semifinite trace $\tau$ and $E$ be a strongly symmetric Banach function space on $[0,\tau(1))$. We show that an operator $x$ in the unit sphere of…

Functional Analysis · Mathematics 2015-02-16 Małgorzata M. Czerwińska , Anna Kamińska

We give a systematic study on the Hardy spaces of functions with values in the non-commutative $L^p$-spaces associated with a semifinite von Neumann algebra ${\cal}M.$ This is motivated by the works on matrix valued Harmonic Analysis…

Classical Analysis and ODEs · Mathematics 2007-06-13 Tao Mei

Given a smooth compact Riemannian manifold $M$ and a Hamiltonian $H$ on the cotangent space $T^*M$, strictly convex and superlinear in the momentum variables, we prove uniqueness of certain ergodic invariant Lagrangian graphs within a given…

Dynamical Systems · Mathematics 2010-12-13 Albert Fathi , Alessandro Giuliani , Alfonso Sorrentino

Let 1 \le p < q \le 2 and let M be any von Neumann algebra. We use recent techniques from free harmonic analysis to construct a completely isomorphic embedding of Lq(M) (equipped with its natural operator space structure) into Lp(A) for…

Operator Algebras · Mathematics 2007-05-23 Marius Junge , Javier Parcet

We consider a family of non-compact manifolds $X_\eps$ (``graph-like manifolds'') approaching a metric graph $X_0$ and establish convergence results of the related natural operators, namely the (Neumann) Laplacian $\laplacian {X_\eps}$ and…

Mathematical Physics · Physics 2009-11-11 Olaf Post

Let (M,J) be an almost complex manifold. We show that the infinite-dimensional space Tau of totally real submanifolds in M carries a natural connection. This induces a canonical notion of geodesics in Tau and a corresponding definition of…

Differential Geometry · Mathematics 2019-04-01 Jason D. Lotay , Tommaso Pacini

Let $\{T(t)\}_{t\geq 0}$ be a $C_0$-semigroup of bounded linear operators on the Banach space ${X}$ into itself and let $A$ be their infinitesimal generator. In this paper, we show that if $T(t)$ is uniformly ergodic, then $A$ does not have…

Functional Analysis · Mathematics 2021-01-21 Abdelaziz Tajmouati , Fatih Barki

In this paper we consider partial metric spaces in the sense of O'Neill. We introduce the notions of strong partial metric spaces and Cauchy functions. We prove a fixed point theorem for such spaces and functions that improves Matthews'…

General Topology · Mathematics 2015-08-18 Samer Assaf , Koushik Pal

The Maurey-Rosenthal theorem states that each bounded and linear operator T from a quasi normed space E into some L_p(\nu) which satisfies a certain vector-valued inequality even allows a weighted norm inequality. Continuing the work of…

Functional Analysis · Mathematics 2016-09-07 Andreas Defant

We generalize the Omori-Yau almost maximum principle of the Laplace-Beltrami operator on a complete Riemannian manifold $M$ to a second-order linear semi-elliptic operator $L$ with bounded coefficients and no zeroth order term. Using this…

Differential Geometry · Mathematics 2013-06-19 Kyusik Hong , Chanyoung Sung