Results 291 to 300 of about 15,157,860 (339)

Existence of Wannier-Stark localization

Physical Review B, 1987
The eigenstates of an electron in an arbitrarily long periodic chain under the influence of an applied electric field are determined. The interaction of the electron with the electric field is divided into two components. The first component has the lattice periodicity and is incorporated into the system's periodic potential.
, Emin, , Hart
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Local Existence and Regularity

University Lecture Series, 2021

semanticscholar   +2 more sources

Comment on ‘‘Existence of Wannier-Stark localization’’

Physical Review B, 1991
It is shown that a recent paper by Emin and Hart [Phys. Rev. B 36, 7353 (1987)], in which a multiband periodic system in an electric field is studied, contains a mathematical error causing the final result and therefore the main conclusion that Wannier-Stark localization still survives in a multiband analysis to be incorrect.
, Leo, , MacKinnon
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Local existence and blow up of solutions to a logarithmic nonlinear wave equation with delay

Applicable Analysis, 2018
This paper is concerned with a problem of a logarithmic nonlinear wave equation with delay. The local existence result has been established using the semigroup theory. In addition, for negative initial energy, a finite-time blow-up result is proved.
Mohammad M. Kafini, S. Messaoudi
semanticscholar   +1 more source

On the existence of f-local subgroups in a group

Siberian Mathematical Journal, 2006
Summary: We prove the existence of infinite subgroups with nontrivial locally finite radicals and of locally finite subgroups in the groups with almost finite almost solvable elements of prime orders and in the groups with generally finite elements.
Sozutov, A. I., Yanchenko, M. V.
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Local existence

2013
Abstract In Chapter 19, we prove local existence of solutions to the initial value problem. The equations we consider are the ones that appear when expressing the Einstein–Vlasov equations with respect to local coordinates (after fixing the gauge). We also derive a continuation criterion.
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Reply to ‘‘Comment on ‘Existence of Wannier-Stark localization’ ’’

Physical Review B, 1990
The argument of Emin and Hart is not that the staircase potential does not couple Bloch states of different energy bands; it does. Rather, the net effect of such interband terms on Wannier-Stark localization is argued to vanish. A new proof of a relationship disputed by Page and Brown is presented.
, Emin, , Hart
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A sharp counterexample to local existence of low regularity solutions to Einstein's equations in wave coordinates

, 2016
We are concerned with how regular initial data have to be to ensure local existence for Einstein's equations in wave coordinates. Klainerman-Rodnianski and Smith-Tataru showed that there in general is local existence for data in Sobolev spaces H^s with ...
B. Ettinger, Hans Lindblad
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Comment on ‘‘Existence of Wannier-Stark localization’’

Physical Review B, 1990
In a recent paper Emin and Hart separated the potential of a constant electric field into two terms: a periodic sawtooth and a staircase. They argued that the sawtooth could be combined with the periodic crystal potential and that the staircase would not induce tunneling between the energy bands of the combined potential. We first show that this would,
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The existence off-local subgroups in a group

Algebra and Logic, 1997
Summary: An infinite subgroup with nontrivial finite radical is called \(f\)-local. We study the structure of subgroups of an infinite fan (set) which contain an element of prime order not embeddable in an \(f\)-local subgroup. It is proven that \(f\)-local and infinite Abelian subgroups exist in groups under certain finiteness conditions.
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