Felix Henneke

Freie Universität Berlin | FUB · Institute of Mathematics

We present a method to construct an efficient approximation to the bare exchange and screened direct interaction kernels of the Bethe-Salpeter Hamiltonian for periodic solid state systems via the interpolative separable density fitting technique. We show that the cost of constructing the approximate Bethe-Salpeter Hamiltonian scales nearly optimall...

A new class of cost functionals for optimal control of quantum systems which produces controls which are sparse in frequency and smooth in time is proposed. This is achieved by penalizing a suitable time-frequency representation of the control field, rather than the control field itself, and by employing norms which are of L¹ or measure form with r...

The fast reaction limit of a volume-surface reaction-diffusion system is rigorously investigated. The system is motivated by proteins localisation in stem cell division. By using Ball's energy equation method, we show that as the reaction rate constant goes to infinity, the solution of the original system converges to the solution of a heat equatio...

A new class of cost functionals for optimal control of quantum systems which produces controls which are sparse in frequency and smooth in time is proposed. This is achieved by penalizing a suitable time-frequency representation of the control field, rather than the control field itself, and by employing norms which are of $L^1$ or measure form wit...

We propose a generalized Suzuki–Trotter (GST) type method for the so-lution of an optimal control problem for quantum molecular systems. The control of such systems gives rise to a minimization problem with constraints given by a system of coupled Schrödinger equations. The bottleneck of the corresponding minimization methods is the solution of tim...