4 papers
Well-posedness and instability of free electron quantum tomography
Florian Oberender
Recent advancements in photon induced near-field electron microscopy (PINEM) enable the preparation, coherent manipulation and characterization of free-electron quantum states. The…
Quantum relative entropy regularization for quantum state tomography
Florian Oberender, Thorsten Hohage
The density matrix is a positive semidefinite operator of trace 1 characterizing the state of a quantum system. We consider the inverse problem to reconstruct such density matrices…
On spurious fixed points in iterative maximum likelihood reconstruction for quantum tomography
Florian Oberender
Maximum likelihood iteration is one of the most commonly used reconstruction algorithms in quantum tomography. The main appeal of the method is that it is easy to implement and tha…
On the instabilities of naive FEM discretizations for PDEs with sign-changing coefficients
Martin Halla, Florian Oberender
We consider a scalar diffusion equation with a sign-changing coefficient in its principle part. The well-posedness of such problems has already been studied extensively provided th…