Franz Georg Fuchs

Reservoir computing on quantum computers has recently emerged as a potential resource for time series prediction, owing to its inherent complex dynamics. To advance Quantum Reservoir Computing (QRC) research, we have developed the Python package QuantumReservoirPy, which facilitates QRC using quantum circuits as reservoirs. The package is designed to be easy to use, while staying completely customizable. The resulting interface, similar to that of reservoirpy (Trouvain et al., 2020), simplifies the development of quantum reservoirs, and provides logical methods of comparison between reservoir architectures.

The quantum approximate optimization algorithm/quantum alternating operator ansatz (QAOA) is a heuristic to find approximate solutions of combinatorial optimization problems. Most of the literature is limited to quadratic problems without constraints. However, many practically relevant optimization problems do have (hard) constraints that need to be fulfilled. In this article, we present a framework for constructing mixing operators that restrict the evolution to a subspace of the full Hilbert space given by these constraints. We generalize the “XY”-mixer designed to preserve the subspace of “one-hot” states to the general case of subspaces given by a number of computational basis states. We expose the underlying mathematical structure which reveals more of how mixers work and how one can minimize their cost in terms of the number of CX gates, particularly when Trotterization is taken into account. Our analysis also leads to valid Trotterizations for an “XY”-mixer with fewer CX gates than is known to date. In view of practical implementations, we also describe algorithms for efficient decomposition into basis gates. Several examples of more general cases are presented and analyzed.

König, Fürsten und Reich im 15. Jahrhundert, hg. von Franz Fuchs, Paul-Joachim Heinig und Jörg Schwarz (Forschungen zur Kaiser- und Papstgeschichte des Mittelalters, Beihefte zu J. F. Böhmer, Regesta Imperii, Band 29). Köln, Weimar, Wien: Böhlau Verlag 2009. VIII und 396 S. ISBN 978-3-412-20473-0. € 49,90

Barbara Gonzaga: Die Briefe / Le Lettere (1455–1508), bearb. von / a cura di Christina Antenhofer, Axel Behne, Daniela Ferrari, Jürgen Herold und Peter Rückert, Übersetzung von / traduzione di Valentina Nucera, Stuttgart: Kohlhammer 2013. 492 S. mit 51 Abb. ISBN 978-3-17-023381-2. Geb. € 49,–

Würzburger Ratsprotokolle 1432–1454, hg. von Franz Fuchs und Ulrich Wagner, bearb. von Antonia Bieber unter Mitwirkung von Anna Maria Fersch und Katharina Räth (Fontes Herbipolenses, Editionen und Studien aus dem Stadtarchiv Würzburg, Bd. 9), Würzburg: Ferdinand Schöningh 2014. 543 S. mit 13 farb. Abb. und 1 Karte. ISBN 978-3-87717-715-0. € 49,–

Wake vortices (WVs) generated by aircraft are a source of risk to the following aircraft. The probability of WV related accidents increases in the vicinity of airport runways due to the shorter time of recovery after a WV encounter. Hence, solutions that can reduce the risk of WV encounters are needed to ensure increased flight safety. In this work we propose an interesting approach to model such wake vortices in real time using a hybrid Eulerian- Lagrangian approach. We derive an appropriate mathematical model, and show a comparison of the different types of solvers. We will conclude with a real life application of the methodology by simulating how wake vortices left behind by an aircraft at the Vffirnes airport in Norway get transported and decay under the influence of a background wind and turbulence field. Although the work demonstrates the application in an aviation context the same approach can be used in a wind energy context.