Publications (40)
Transmission eigenvalues for elliptic operators
Michael Hitrik, Katsiaryna Krupchyk, Petri Ola +1
A reduction of the transmission eigenvalue problem for multiplicative sign-definite perturbations of elliptic operators with constant coefficients to an eigenvalue problem for a no…
Weighted symbol spaces, magnetic translations, and pseudodifferential operators
Michael Hitrik, Reid Johnson
We study pseudodifferential operators associated to microlocally defined normed symbol spaces of limited regularity, introduced by J. Sjöstrand. Boundedness of such operators on m…
Transmission eigenvalues for operators with constant coefficients
Michael Hitrik, Katsiaryna Krupchyk, Petri Ola +1
In this paper we study the interior transmission problem and transmission eigenvalues for multiplicative perturbations of linear partial differential operator of order with…
Supersymmetric structures for second order differential operators
Frederic Herau, Michael Hitrik, Johannes Sjoestrand
Necessary and sufficient conditions are obtained for a real semiclassical partial differential operator of order two to possess a supersymmetric structure. For the operator coming…
Eigenvalues and subelliptic estimates for non-selfadjoint semiclassical operators with double characteristics
Michael Hitrik, Karel Pravda-Starov
For a class of non-selfadjoint --pseudodifferential operators with double characteristics, we give a precise description of the spectrum and establish accurate semiclassical res…
Diophantine tori and spectral asymptotics for non-selfadjoint operators
Michael Hitrik, Johannes Sjoestrand, San Vu Ngoc
We study spectral asymptotics for small non-selfadjoint perturbations of selfadjoint -pseudodifferential operators in dimension 2, assuming that the classical flow of the unpert…