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Related papers: On a class of Model Hilbert Spaces

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This paper is a detailed study of finite-dimensional modules defined on bicomplex numbers. A number of results are proved on bicomplex square matrices, linear operators, orthogonal bases, self-adjoint operators and Hilbert spaces, including…

Functional Analysis · Mathematics 2011-08-10 Raphael Gervais Lavoie , Louis Marchildon , Dominic Rochon

We construct a class of representations of the Heisenberg algebra in terms of the complex shift operators subject to the proper continuous limit imposed by the correspondence principle. We find a suitable Hilbert space formulation of our…

High Energy Physics - Theory · Physics 2007-05-23 Andrzej Z. Gorski , Jacek Szmigielski

We introduce compactness classes of Hilbert space operators by grouping together all operators for which the associated singular values decay at a certain speed and establish upper bounds for the norm of the resolvent of operators belonging…

Spectral Theory · Mathematics 2020-05-29 Ayse Guven , Oscar F. Bandtlow

We construct a rigged Hilbert space for the square integrable functions on the line L^2(R) adding to the generators of the Weyl-Heisenberg algebra a new discrete operator, related to the degree of the Hermite polynomials. All together,…

Mathematical Physics · Physics 2015-02-18 Enrico Celeghini

We use a model operator approach and the spectral theorem for self-adjoint operators in a Hilbert space to derive the basic results of abstract left-definite theory in a straightforward manner. The theory is amply illustrated with a variety…

Spectral Theory · Mathematics 2024-08-06 Christoph Fischbacher , Fritz Gesztesy , Paul Hagelstein , Lance Littlejohn

In this study, the properties of an oscillating system composed of a pendulum connected to a seesaw and placed on a moving platform with a certain slope are analyzed. Using complex numbers to collect the information contained in the system…

Finite rank perturbations of a semi-bounded self-adjoint operator A are studied in the scale of Hilbert spaces associated with A. A concept of quasi-boundary value space is used to describe self-adjoint operator realizations of regular and…

Mathematical Physics · Physics 2012-03-06 S. Albeverio , S. Kuzhel , L. Nizhnik

We study expansions of Hilbert spaces with a bounded normal operator $T$. We axiomatize this theory in a natural language and identify all of its completions. We prove the definability of the adjoint $T^*$ and prove quantifier elimination…

Logic · Mathematics 2025-07-30 Alexander Berenstein , Nicolás Cuervo Ovalle , Isaac Goldbring

We discuss some basic properties of Lie group representations in rigged Hilbert spaces. In particular, we show that a differentiable representation in a rigged Hilbert space may be obtained as the projective limit of a family of continuous…

Mathematical Physics · Physics 2009-11-10 S. Wickramasekara , A. Bohm

In this paper, we shall consider the notion of bicomplex inner product and define bicomplex Hilbert space. We shall define $L^{2}[a,b]$ where the functions take bicomplex values. We shall prove the Theorem for a bounded self adjoint…

Functional Analysis · Mathematics 2024-02-27 Akshay Sakharam Rane

We consider a second order difference equation with operator-valued coefficients. More precisely, we study either compact or trace class perturbations of the discrete Laplacian in the Hilbert space of bi-infinite square-summable sequence…

Spectral Theory · Mathematics 2025-01-22 David Sher , Luis Silva , Boris Vertman , Monika Winklmeier

Traditional machine learning models, particularly neural networks, are rooted in finite-dimensional parameter spaces and nonlinear function approximations. This report explores an alternative formulation where learning tasks are expressed…

Machine Learning · Computer Science 2025-07-30 Andrew Kiruluta , Andreas Lemos , Priscilla Burity

Criteria are formulated both for the existence and for the non-existence of complex eigenvalues for a class of non self-adjoint operators in Hilbert space invarariant under a particular discrete symmetry. Applications to the PT-symmetric…

Mathematical Physics · Physics 2009-11-10 Emanuela Caliceti , Sandro Graffi , Johannes Sjoestrand

The scope of this text is to study a process that induces another proof of the Spectral Embedding Theorem: that any densely defined symmetric operator can be extended by a multiplication operator through an embedding of the Hilbert space…

Functional Analysis · Mathematics 2026-05-29 Fabrice Nonez

In this paper we consider a problem of the similarity of complex symmetric operators to perturbations of restrictions of normal operators. For a subclass of cyclic complex symmetric operators in a finite-dimensional Hilbert space we prove…

Functional Analysis · Mathematics 2021-06-29 Sergey M. Zagorodnyuk

Using the bicomplex numbers $\mathbb{T}$ which is a commutative ring with zero divisors defined by $\mathbb{T}=\{w_0 + w_1 i_1 + w_2 i_2 + w_3 j | w_0, w_1, w_2, w_3 \in \mathbb{R}\}$ where $i_{1}^{2} = -1, i_{2}^{2} = -1, j^2 = 1, i_1 i_2…

Quantum Physics · Physics 2013-07-10 Dominic Rochon , Sebastien Tremblay

The purpose of the paper is to introduce and study a new class of operators on semi-Hilbertian spaces i.e.; spaces generated by positive semidefinite sesquilinear forms. Let H be a Hilbert space and let A be a positive bounded operator on H…

General Mathematics · Mathematics 2019-12-09 Samir Al Mohammady , Sid Ahmed Ould Beinane , Sid Ahmed O. Ahmed Mahmoud

Motivated by importance of operator spaces contained in the set of all scalar multiples of isometries ($MI$-spaces) in a separable Hilbert space for $C^*$-algebras and E-semigroups we exhibit more properties of such spaces. For example, if…

Operator Algebras · Mathematics 2008-05-23 Waclaw Szymanski

The notion of B-convexity for operator spaces, which a priori depends on a set of parameters indexed by $\Sigma$, is defined. Some of the classical characterizations of this geometric notion for Banach spaces are studied in this new…

Operator Algebras · Mathematics 2007-05-23 Javier Parcet

This paper will initiate a study on the class of complex symmetric operators acting between two different Hilbert space. Among other things, we compute the closure of CSO with respect to the several topologies.

Functional Analysis · Mathematics 2016-02-15 Mona Nabiei