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arXiv · 0803.2552

On the nature of ill-posedness of the forward-backward heat equation

Marina Chugunova·Illya M. Karabash·Sergei G. Pyatkov
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Abstract

We study the Cauchy problem with periodic initial data for the forward-backward heat equation defined by the J-self-adjoint linear operator L depending on a small parameter. The problem has been originated from the lubrication approximation of a viscous fluid film on the inner surface of the rotating cylinder. For a certain range of the parameter we rigorously prove the conjecture, based on the numerical evidence, that the set of eigenvectors of the operator $L$ does not form a Riesz basis in $\L^2 (-\pi,\pi)$. Our method can be applied to a wide range of the evolutional problems given by $PT-$symmetric operators.

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Marina Chugunova, Illya M. Karabash, Sergei G. Pyatkov. 2008-03-18. On the nature of ill-posedness of the forward-backward heat equation. https://doi.org/10.1007/s00020-009-1720-z

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