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Related papers: Projection operators in the Weihrauch lattice

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We consider $C$-compact orthogonally additive operators in vector lattices. After providing some examples of $C$-compact orthogonally additive operators on a vector lattice with values in a Banach space we show that the set of those…

Functional Analysis · Mathematics 2019-12-11 Marat Pliev , Martin R. Weber

We generalize the notion of an intertwining operator to N-graded weak modules over a vertex operator algebra and study their properties. We show a formula for the dimensions of these intertwining operators in terms of modules over the Zhu…

Quantum Algebra · Mathematics 2017-09-21 Kenichiro Tanabe

Plemelj projection operators are introduced for spaces of square integrable functions defined over the boundaries of a class of compact real n-dimensional manifolds lying in C^n. These manifolds posses many properties similar to domains in…

Complex Variables · Mathematics 2007-05-23 John Ryan

We establish sharp pointwise estimates for the ground states of some singular fractional Schr\"odinger operators on relatively compact Euclidean subsets. The considered operators are of the type $(-\Delta)^{\alpha/2}|_\Omega-V$, where $V\in…

Spectral Theory · Mathematics 2018-08-13 Mohamed Ali Beldi

The problem of immersing a simply connected surface with a prescribed shape operator is discussed. From classical and more recent work, it is known that, aside from some special degenerate cases, such as when the shape operator can be…

Differential Geometry · Mathematics 2007-05-23 Robert L. Bryant

In this paper we develop a general concept of Lax operators on algebraic curves introduced in [1]. We observe that the space of Lax operators is closed with respect to their usual multiplication as matrix-valued functions. We construct the…

Representation Theory · Mathematics 2011-02-11 Igor M. Krichever , Oleg K. Sheinman

The Euclidean operator radius of two bounded linear operators in the Hilbert $C^*$-module over $\A$ is given some precise bounds. Their relationship to recent findings in the literature that offer precise upper and lower bounds on the…

Functional Analysis · Mathematics 2023-07-06 M. H. M. Rashid

We study ordinal-indexed, multi-layer iterations of bounded operator transforms and prove convergence to spectral/ergodic projections under functional-calculus hypotheses. For normal operators on Hilbert space and polynomial or holomorphic…

Functional Analysis · Mathematics 2025-08-11 Faruk Alpay , Taylan Alpay , Hamdi Alakkad

The subgradient projector is of considerable importance in convex optimization because it plays the key role in Polyak's seminal work - and the many papers it spawned - on subgradient projection algorithms for solving convex feasibility…

Optimization and Control · Mathematics 2014-03-28 Heinz H. Bauschke , Caifang Wang , Xianfu Wang , Jia Xu

In this paper we find all complex symmetric weighted composition operators with special conjugations. Then we give spectral properties of these complex symmetric weighted composition operators.

Functional Analysis · Mathematics 2018-04-10 Mahsa Fatehi

Quasi-isometric liftings similar to isometries, for the operators similar to contractions in Hilbert spaces, are investigated. The existence of such liftings is established, and their applications are explored for specific operator classes,…

Functional Analysis · Mathematics 2025-01-27 Laurian Suciu , Andra-Maria Stoica

We study Birkhoff-James orthogonality of compact (bounded) linear operators between Hilbert spaces and Banach spaces. Applying the notion of semi-inner-products in normed linear spaces and some related geometric ideas, we generalize and…

Functional Analysis · Mathematics 2018-10-12 Debmalya Sain , Kallol Paul , Arpita Mal

In this paper, we study the generalized differentiability of the metric projection operator onto the positive cone in Hilbert spaces. We first establish the formula for exactly computing the regular coderivative and the Mordukhovich…

Functional Analysis · Mathematics 2024-07-12 Le Van Hien , Nguyen Viet Quan

Quantum Iterated Function System on a complex projective space is defined by a family of linear operators on a complex Hilbert space. The operators define both the maps and their probabilities by one algebraic formula. Examples with…

Chaotic Dynamics · Physics 2009-11-10 Arkadiusz Jadczyk

In this paper, we describe some arithmetic properties of Lame operators with finite dihedral projective monodromy. We take advantage of the deep link with Grothendieck's theory of dessins d'enfants. We focus more particularly on the case of…

Number Theory · Mathematics 2007-05-23 Leonardo Zapponi

Orthogonal projections onto closed subspaces of $H^2(\mathbb{D}^n)$ of the form $\varphi H^2(\mathbb{D}^n)$ for inner functions $\varphi$ on $\mathbb{D}^n$ are referred to as inner projections, where $H^2(\mathbb{D}^n)$ denotes the Hardy…

Functional Analysis · Mathematics 2023-10-24 Ramlal Debnath , Deepak K. Pradhan , Jaydeb Sarkar

Projection operators are important in Analysis, Optimization and Algorithm. It is well known that these operators are firmly nonexpansive. In this paper, we provide an exact result that sharpens this well-known result. We develop the theory…

Functional Analysis · Mathematics 2025-07-23 Shuang Song

We study the numerical range of bounded linear operators on quaternionic Hilbert spaces and its relation with the S-spectrum. The class of complex operators on quaternionic Hilbert spaces is introduced and the upper bild of normal complex…

Functional Analysis · Mathematics 2022-10-12 Luís Carvalho , Cristina Diogo , Sérgio Mendes

In the paper we study the algebroid A of the groupoid of partially invertible elements over the lattice of orthogonal projections of a $W^*$-algebra. In particular the complex analytic manifold structure of these objects is investigated.…

Differential Geometry · Mathematics 2015-12-09 Anatol Odzijewicz , Grzegorz Jakimowicz , Aneta Sliżewska

In this paper, we investigate weighted composition, Volterra and Integral operators on second derivative Hardy spaces. Some equivalent conditions for boundedness of the operators will be given using the boundedness on the Hardy spaces. Also…

Functional Analysis · Mathematics 2022-10-13 Mostafa Hassanlou , Ebrahim Abbasi