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WKB expansion for systems of Schrödinger operators with crossing eigenvalues

Pettersson, Pelle LU (1997) In Asymptotic Analysis 14(1). p.1-48
Abstract

Let M be a compact, connected C∞ manifold with a C∞ Riemannian metric or let M=Rn with Euclidean metric. Let g denote the metric. On M consider the 2×2 system of Schrödinger operators

[TeX:] \[P=-h^{2}\Delta +V+h^{2}\mathcal{W},\qquadV=\left(\begin{array}[cc]v_{1}&0\\0&v_{2}\end{array}\right)\]where v1,v2∈C∞(M) are non-negative, and W is a C∞, first order formally selfadjoint differential operator with real coefficients. We study the eigenfunctions of P corresponding to the lowest eigenvalues in the semi-classical limit h→0. They are concentrated near a minimal geodesic γ with... (More)

Let M be a compact, connected C∞ manifold with a C∞ Riemannian metric or let M=Rn with Euclidean metric. Let g denote the metric. On M consider the 2×2 system of Schrödinger operators

[TeX:] \[P=-h^{2}\Delta +V+h^{2}\mathcal{W},\qquadV=\left(\begin{array}[cc]v_{1}&0\\0&v_{2}\end{array}\right)\]where v1,v2∈C∞(M) are non-negative, and W is a C∞, first order formally selfadjoint differential operator with real coefficients. We study the eigenfunctions of P corresponding to the lowest eigenvalues in the semi-classical limit h→0. They are concentrated near a minimal geodesic γ with respect to the Agmon metric vg, v = min(v1, v2), connecting two non-degenerate zeros of v (wells). This metric is Lipschitz continuous but not C2 at [TeX:] $\varGamma =\{x\in M;\ v_{1}(x)=v_{2}(x)\}$. When the derivative of v1 - v2 along γ does not vanish on [TeX:] $\gamma \cap \varGamma $ and the intersection is transversal we obtain WKB expansions of the eigenfunctions. At [TeX:] $\gamma \cap \varGamma $ they are expressed in terms of derivatives Yk,ε=∂kYε/∂εk of suitable parabolic cylinder functions Yε. As an application of the WKB constructions we compute the splitting due to tunnelling of the lowest eigenvalues of P under a strong symmetry condition. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Asymptotic Analysis
volume
14
issue
1
pages
1 - 48
publisher
I O S Press
external identifiers
  • scopus:1642357501
ISSN
0921-7134
DOI
10.3233/ASY-1997-14101
language
English
LU publication?
yes
id
a4c6ca4e-5758-41ce-bf11-06000c0a0d1f
date added to LUP
2022-04-07 12:56:50
date last changed
2023-05-02 04:02:27
@article{a4c6ca4e-5758-41ce-bf11-06000c0a0d1f,
  abstract     = {{<p class="first" style="box-sizing: border-box; margin: 0em 0px; color: rgb(65, 65, 65); font-family: &quot;PT Serif&quot;, serif; font-size: 16px;">Let M be a compact, connected C∞ manifold with a C∞ Riemannian metric or let M=Rn with Euclidean metric. Let g denote the metric. On M consider the 2×2 system of Schrödinger operators</p>[TeX:] \[P=-h^{2}\Delta +V+h^{2}\mathcal{W},\qquadV=\left(\begin{array}[cc]v_{1}&amp;0\\0&amp;v_{2}\end{array}\right)\]where v1,v2∈C∞(M) are non-negative, and W is a C∞, first order formally selfadjoint differential operator with real coefficients. We study the eigenfunctions of P corresponding to the lowest eigenvalues in the semi-classical limit h→0. They are concentrated near a minimal geodesic γ with respect to the Agmon metric vg, v = min(v1, v2), connecting two non-degenerate zeros of v (wells). This metric is Lipschitz continuous but not C2 at [TeX:] $\varGamma =\{x\in M;\ v_{1}(x)=v_{2}(x)\}$. When the derivative of v1 - v2 along γ does not vanish on [TeX:] $\gamma \cap \varGamma $ and the intersection is transversal we obtain WKB expansions of the eigenfunctions. At [TeX:] $\gamma \cap \varGamma $ they are expressed in terms of derivatives Yk,ε=∂kYε/∂εk of suitable parabolic cylinder functions Yε. As an application of the WKB constructions we compute the splitting due to tunnelling of the lowest eigenvalues of P under a strong symmetry condition.}},
  author       = {{Pettersson, Pelle}},
  issn         = {{0921-7134}},
  language     = {{eng}},
  number       = {{1}},
  pages        = {{1--48}},
  publisher    = {{I O S Press}},
  series       = {{Asymptotic Analysis}},
  title        = {{WKB expansion for systems of Schrödinger operators with crossing eigenvalues}},
  url          = {{http://dx.doi.org/10.3233/ASY-1997-14101}},
  doi          = {{10.3233/ASY-1997-14101}},
  volume       = {{14}},
  year         = {{1997}},
}