scholarly journals Local Approximation of Observables and Commutator Bounds

2012 ◽  
pp. 143-149 ◽  
Author(s):  
Bruno Nachtergaele ◽  
Volkher B. Scholz ◽  
Reinhard F. Werner
Keyword(s):  
Local Approximation

DEVELOPMENTS OF THE LOCAL APPROXIMATION FOR DISORDERED SYSTEMS

1972 ◽  
Vol 33 (C3) ◽  
pp. C3-135-C3-143 ◽  
Author(s):  
W. KOHN ◽  
J. OLSON
Keyword(s):  
Disordered Systems ◽  
Local Approximation

Weighted inequalities and applications to best local approximation in Luxemburg norm

2004 ◽  
Vol 20 (3) ◽  
pp. 265-280 ◽  
Author(s):  
H. H. Cuenya ◽  
M. D. Lorenzo ◽  
C. N. Rodriguez
Keyword(s):  
Local Approximation ◽  
Weighted Inequalities ◽  
Luxemburg Norm ◽  
Best Local Approximation

scholarly journals On the local approximation of mean densities of random closed sets

Bernoulli ◽  
2014 ◽  
Vol 20 (1) ◽  
pp. 1-27 ◽  
Author(s):  
Elena Villa
Keyword(s):  
Local Approximation ◽  
Closed Sets ◽  
Random Closed Sets

Jeffery-Hamel boundary-layer flows over curved beds

1988 ◽  
Vol 186 ◽  
pp. 583-597 ◽  
Author(s):  
P. M. Eagles
Keyword(s):  
Boundary Layer ◽  
Flow Field ◽  
Film Flow ◽  
Local Approximation ◽  
Main Stream ◽  
Streamwise Direction ◽  
Boundary Layer Flows ◽  
Boundary Layer Equations ◽  
First Approximation ◽  
Local Value

We find certain exact solutions of Jeffery-Hamel type for the boundary-layer equations for film flow over certain beds. If β is the angle of the bed with the horizontal and S is the arclength these beds have equation sin β = (const.)S−3, and allow a description of flows on concave and convex beds. The velocity profiles are markedly different from the semi-Poiseuille flow on a plane bed.We also find a class of beds in which the Jeffery-Hamel flows appear as a first approximation throughout the flow field, which is infinite in streamwise extent. Since the parameter γ specifying the Jeffery-Hamel flow varies in the streamwise direction this allows a description of flows over curved beds which are slowly varying, as described in the theory, in such a way that the local approximation is that Jeffery-Hamel flow with the local value of γ. This allows the description of flows with separation and reattachment of the main stream in some cases.

scholarly journals A computational approach for investigating Coulomb interaction using Wigner–Poisson coupling

2021 ◽  
Author(s):  
Majid Benam ◽  
Mauro Ballicchia ◽  
Josef Weinbub ◽  
Siegfried Selberherr ◽  
Mihail Nedjalkov
Keyword(s):  
Coulomb Interaction ◽  
Spectral Decomposition ◽  
Electron System ◽  
Local Approximation ◽  
Computational Effort ◽  
Computational Approach ◽  
Electron Interaction ◽  
Quantum Particles ◽  
Interacting Electrons ◽  
Poisson Coupling

AbstractEntangled quantum particles, in which operating on one particle instantaneously influences the state of the entangled particle, are attractive options for carrying quantum information at the nanoscale. However, fully-describing entanglement in traditional time-dependent quantum transport simulation approaches requires significant computational effort, bordering on being prohibitive. Considering electrons, one approach to analyzing their entanglement is through modeling the Coulomb interaction via the Wigner formalism. In this work, we reduce the computational complexity of the time evolution of two interacting electrons by resorting to reasonable approximations. In particular, we replace the Wigner potential of the electron–electron interaction by a local electrostatic field, which is introduced through the spectral decomposition of the potential. It is demonstrated that for some particular configurations of an electron–electron system, the introduced approximations are feasible. Purity, identified as the maximal coherence for a quantum state, is also analyzed and its corresponding analysis demonstrates that the entanglement due to the Coulomb interaction is well accounted for by the introduced local approximation.

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