Results 31 to 40 of about 1,370 (227)

Characterization of Eigenvalues in Spectral Gap for Singular Differential Operators

Abstract and Applied Analysis, 2012
The spectral properties for n order differential operators are considered. When given a spectral gap (a,b) of the minimal operator T0 with deficiency index r, arbitrary m points βi  (i=1,2,…,m) in (a,b), and a positive integer function p such that ∑i=1mp(
Zhaowen Zheng, Wenju Zhang
doaj   +1 more source

Spectra of Elliptic Operators on Quantum Graphs with Small Edges

Mathematics, 2021
We consider a general second order self-adjoint elliptic operator on an arbitrary metric graph, to which a small graph is glued. This small graph is obtained via rescaling a given fixed graph γ by a small positive parameter ε.
Denis I. Borisov
doaj   +1 more source

On self-adjoint operators in Krein spaces constructed by Clifford algebra Cl_{2} [PDF]

Opuscula Mathematica, 2012
Let \(J\) and \(R\) be anti-commuting fundamental symmetries in a Hilbert space \(\mathfrak{H}\). The operators \(J\) and \(R\) can be interpreted as basis (generating) elements of the complex Clifford algebra \(Cl_2(J,R):=\text{span}\{I,J,R,iJR\}\).
Sergii Kuzhel, Olexiy Patsyuck
doaj   +1 more source

Quantum Models à la Gabor for the Space-Time Metric

Entropy, 2022
As an extension of Gabor signal processing, the covariant Weyl-Heisenberg integral quantization is implemented to transform functions on the eight-dimensional phase space x,k into Hilbertian operators.
Gilles Cohen-Tannoudji, Jean-Pierre Gazeau, Célestin Habonimana, Juma Shabani   +3 more
doaj   +1 more source

Green's Function and Convergence of Fourier Series for Elliptic Differential Operators with Potential from Kato Space

Abstract and Applied Analysis, 2010
We consider the Friedrichs self-adjoint extension for a differential operator A of the form A=A0+q(x)⋅, which is defined on a bounded domain Ω⊂ℝn, n≥1 (for n=1 we assume that Ω=(a,b) is a finite interval). Here A0=A0(x,D) is a formally self-adjoint and a
Valery Serov
doaj   +1 more source

Simplicity and Spectrum of Singular Hamiltonian Systems of Arbitrary Order

Abstract and Applied Analysis, 2013
The paper is concerned with singular Hamiltonian systems of arbitrary order with arbitrary equal defect indices. It is proved that the minimal operator generated by the Hamiltonian system is simple.
Huaqing Sun
doaj   +1 more source

Quasi boundary triples and semi-bounded self-adjoint extensions [PDF]

Proceedings of the Royal Society of Edinburgh: Section A Mathematics, 2017
In this note semi-bounded self-adjoint extensions of symmetric operators are investigated with the help of the abstract notion of quasi boundary triples and their Weyl functions. The main purpose is to provide new sufficient conditions on the parameters in the boundary space to induce self-adjoint realizations, and to relate the decay of the Weyl ...
Behrndt, Jussi, Langer, Matthias, Lotoreichik, Vladimir, Rohleder, Jonathan   +3 more
openaire   +3 more sources

Bridging Optical and Mechanical Metamaterial/Metasurface Realms Toward Integrated Meta‐Systems

Advanced Optical Materials, EarlyView.
This perspective describes the rise of metamaterials in the field of materials science, specifically with optical and mechanical functionality. Fundamentals of both optical and mechanical metamaterials are discussed with a review of state‐of‐the‐art metamaterial science.
Justin Brackenridge, Jaejun Lee, Vladimir V. Tsukruk   +2 more
wiley   +1 more source

Self-adjoint and non-self-adjoint extensions of symmetric q-Sturm-Liouville operators

Filomat, 2023
Aspace of boundary values is constructed for minimal symmetric regular and singular q-Sturm- Liouville operators in limit-point and limit-circle cases. A description of all maximal dissipative, maximal accumulative, self-adjoint, and other extensions of such symmetric q-Sturm-Liouville operators is given in terms of boundary conditions.
Isayev, Hamlet A., Allahverdiev, Bilender P.   +1 more
openaire   +2 more sources

Advanced control of non‐isothermal axial dispersion tubular reactors with recycle‐induced state delay

The Canadian Journal of Chemical Engineering, EarlyView.
Abstract We develop a delay‐aware estimation and control framework for a non‐isothermal axial dispersion tubular reactor modelled as a coupled parabolic‐hyperbolic PDE system with recycle‐induced state delay. The infinite‐dimensional dynamics are preserved without spatial discretization by representing the delay as a transport PDE and adopting a late ...
Behrad Moadeli, Stevan Dubljevic
wiley   +1 more source