Ambarzumian theorem for quantum graphs with magnetic potential
DOI:
https://doi.org/10.7146/math.scand.a-157030Abstract
A Schrödinger operator on a metric graph is isospectral to the Laplacian if and only if the potential is zero. This result is extended to the case of magnetic Schrödinger operators. We show that if a magnetic Schrödinger operator is isospectral to the Laplacian then the magnetic potential can be eliminated. Even the case of delta couplings at the vertices is considered.
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