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Confining quantum particles with a purely magnetic field

Yves Colin de Verdière, Françoise Truc (2010)

Annales de l’institut Fourier

We consider a Schrödinger operator with a magnetic field (and no electric field) on a domain in the Euclidean space with a compact boundary. We give sufficient conditions on the behaviour of the magnetic field near the boundary which guarantees essential self-adjointness of this operator. From the physical point of view, it means that the quantum particle is confined in the domain by the magnetic field. We construct examples in the case where the boundary is smooth as well as for polytopes; These...

Continuum spectrum for the linearized extremal eigenvalue problem with boundary reactions

Futoshi Takahashi (2014)

Mathematica Bohemica

We study the semilinear problem with the boundary reaction - Δ u + u = 0 in Ω , u ν = λ f ( u ) on Ω , where Ω N , N 2 , is a smooth bounded domain, f : [ 0 , ) ( 0 , ) is a smooth, strictly positive, convex, increasing function which is superlinear at , and λ > 0 is a parameter. It is known that there exists an extremal parameter λ * > 0 such that a classical minimal solution exists for λ < λ * , and there is no solution for λ > λ * . Moreover, there is a unique weak solution u * corresponding to the parameter λ = λ * . In this paper, we continue to study the spectral properties of u * and show...

Domain perturbations, capacity and shift of eigenvalues

André Noll (1999)

Journées équations aux dérivées partielles

After introducing the notion of capacity in a general Hilbert space setting we look at the spectral bound of an arbitrary self-adjoint and semi-bounded operator H . If H is subjected to a domain perturbation the spectrum is shifted to the right. We show that the magnitude of this shift can be estimated in terms of the capacity. We improve the upper bound on the shift which was given in Capacity in abstract Hilbert spaces and applications to higher order differential operators (Comm. P. D. E., 24:759–775,...

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