MaPhySto
The Danish National Research Foundation:
Network in Mathematical Physics and Stochastics

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Funded by The Danish National Research Foundation

Mathematical Physics Seminar

Abstract
Various results concerning the smoothness of gap boundaries for Harper type operators are extended to a large class of "twisted integral operatos" in $L^2(Z^2)$. The results hold true also for analogous classes of operators in $L^2(R^n)$ and imply the fact that the gap boundaries for magnetic Schrodinger and Dirac operators are, up to a logarithmic factor, Lipschitz continuous in the magnetic field strenght. The proofs are based on gauge covariance and magnetic perturbation theory

Contact person:Arne Jensen.