TY - JOUR A1 - Höfling, Felix A1 - Straube, Arthur T1 - Langevin equations and a geometric integration scheme for the overdamped limit of rotational Brownian motion of axisymmetric particles JF - Physical Review Research N2 - The translational motion of anisotropic or self-propelled colloidal particles is closely linked with the particle’s orientation and its rotational Brownian motion. In the overdamped limit, the stochastic evolution of the orientation vector follows a diffusion process on the unit sphere and is characterized by an orientation-dependent (“multiplicative”) noise. As a consequence, the corresponding Langevin equation attains different forms depending on whether Itō’s or Stratonovich’s stochastic calculus is used. We clarify that both forms are equivalent and derive them in a top-down approach from a geometric construction of Brownian motion on the unit sphere, based on infinitesimal random rotations. Our approach suggests further a geometric integration scheme for rotational Brownian motion, which preserves the normalization constraint of the orientation vector exactly. We show that a simple implementation of the scheme, using Gaussian random rotations, converges weakly at order 1 of the integration time step, and we outline an advanced variant of the scheme that is weakly exact for an arbitrarily large time step. Due to a favorable prefactor of the discretization error, already the Gaussian scheme allows for integration time steps that are one order of magnitude larger compared to a commonly used algorithm for rotational Brownian dynamics simulations based on projection on the constraining manifold. For torques originating from constant external fields, we prove by virtue of the Fokker-Planck equation that the constructed diffusion process satisfies detailed balance and converges to the correct equilibrium distribution. The analysis is restricted to time-homogeneous rotational Brownian motion (i.e., a single rotational diffusion constant), which is relevant for axisymmetric particles and also chemically anisotropic spheres, such as self-propelled Janus particles. Y1 - 2025 U6 - https://doi.org/10.1103/wzdn-29p4 VL - 7 SP - 043034 ER - TY - JOUR A1 - Schaible, Jonas A1 - Winarto, Hanifah A1 - Škorjanc, Viktor A1 - Yoo, Danbi A1 - Zimmermann, Lea A1 - Jäger, Klaus A1 - Sekulic, Ivan A1 - Schneider, Philipp‐Immanuel A1 - Burger, Sven A1 - Wessels, Andreas A1 - Bläsi, Benedikt A1 - Becker, Christiane T1 - Optimizing Aesthetic Appearance of Perovskite Solar Cells Using Color Filters JF - Solar RRL N2 - The significance of color aesthetics in photovoltaic (PV) modules gains importance, especially in design‐centric applications like building‐integrated PVs. Color filters based on distributed Bragg reflectors, consisting of alternating thin‐film layers of different refractive indices, can modify the appearance of standard silicon modules. This approach is also extended to optimize the color appearance of emerging PV technologies such as perovskite solar cells, which typically exhibit a less appealing gray–brownish appearance. In this contribution, perovskite solar‐cell stacks combined with MorphoColor color filters are presented. Angular‐resolved reflectance simulations based on wave optics and ray tracing with experimental data are validated, and the color appearance from various viewing angles is evaluated. Additionally, the impact of individual layers on color appearance and the maximum achievable short‐circuit current density in the perovskite solar cell is investigated. By applying Bayesian optimization, the color distance is minimized to the targeted appearance. Tailoring the bridging layers between the color filter and the perovskite solar cell is found to strongly influence the color impression due to the coherently combined color filter and perovskite solar cell. The presented color optimization concept allows to customize the aesthetics of emerging PV thin‐film technologies such as perovskite solar cells. Y1 - 2025 U6 - https://doi.org/10.1002/solr.202400627 VL - 9 SP - 2400627 PB - Wiley ER - TY - GEN A1 - Roche, Léo J. A1 - Betz, Fridtjof A1 - Yang, Yuhui A1 - Limame, Imad A1 - Shih, Ching-Wen A1 - Burger, Sven A1 - Reitzenstein, Stephan T1 - Inside Front Cover: Numerical Investigation of a Coupled Micropillar - Waveguide System for Integrated Quantum Photonic Circuits (Adv. Quantum Technol. 12/2024) T2 - Adv. Quantum Technol. Y1 - 2024 U6 - https://doi.org/10.1002/qute.202470036 VL - 7 SP - 2470036 ER - TY - CHAP A1 - Mukherjee, Deshabrato A1 - Burger, Sven A1 - Siefke, Thomas A1 - Gour, Jeetendra A1 - Bodermann, Bernd A1 - Petrik, Peter T1 - Modeling of dimensions and sensing properties of gold gratings by spectroscopic ellipsometry and finite element method T2 - EPJ Web of Conferences Y1 - 2024 U6 - https://doi.org/10.1051/epjconf/202430902016 VL - 309 SP - 02016 ER - TY - JOUR A1 - Djurdjevac Conrad, Natasa A1 - Tonello, Elisa A1 - Zonker, Johannes A1 - Siebert, Heike T1 - Detection of dynamic communities in temporal networks with sparse data JF - Applied Network Science N2 - Temporal networks are a powerful tool for studying the dynamic nature of a wide range of real-world complex systems, including social, biological and physical systems. In particular, detection of dynamic communities within these networks can help identify important cohesive structures and fundamental mechanisms driving systems behaviour. However, when working with real-world systems, available data is often limited and sparse, due to missing data on systems entities, their evolution and interactions, as well as uncertainty regarding temporal resolution. This can hinder accurate representation of the system over time and result in incomplete or biased community dynamics. In this paper, we compare established methods for community detection and, using synthetic data experiments and real-world case studies, we evaluate the impact of data sparsity on the quality of identified dynamic communities. Our results give valuable insights on the evolution of systems with sparse data, which are less studied in existing literature, but are frequently encountered in real-world applications. Y1 - 2025 U6 - https://doi.org/10.1007/s41109-024-00687-3 VL - 10 PB - Springer International Publishing ER - TY - JOUR A1 - Zimper, Sebastian A1 - Cornalba, Federico A1 - Djurdjevac Conrad, Natasa A1 - Djurdjevac, Ana T1 - On reduced inertial PDE models for Cucker-Smale flocking dynamics JF - Proceedings of the Royal Society A N2 - In particle systems, flocking refers to the phenomenon where particles’ individual velocities eventually align. The Cucker-Smale model is a well-known mathematical framework that describes this behaviour. Many continuous descriptions of the Cucker-Smale model use PDEs with both particle position and velocity as independent variables, thus providing a full description of the particles mean-field limit (MFL) dynamics. In this paper, we introduce a novel reduced inertial PDE model consisting of two equations that depend solely on particle position. In contrast to other reduced models, ours is not derived from the MFL, but directly includes the model reduction at the level of the empirical densities, thus allowing for a straightforward connection to the underlying particle dynamics. We present a thorough analytical investigation of our reduced model, showing that: firstly, our reduced PDE satisfies a natural and interpretable continuous definition of flocking; secondly, in specific cases, we can fully quantify the discrepancy between PDE solution and particle system. Our theoretical results are supported by numerical simulations. Y1 - 2025 U6 - https://doi.org/https://doi.org/10.1098/rspa.2024.0675 VL - 481 PB - Royal Society ER - TY - JOUR A1 - Fischbach, Jan David A1 - Betz, Fridtjof A1 - Asadova, Nigar A1 - Tassan, Pietro A1 - Urbonas, Darius A1 - Stöferle, Thilo A1 - Mahrt, Rainer F. A1 - Burger, Sven A1 - Rockstuhl, Carsten A1 - Binkowski, Felix A1 - Sturges, Thomas Jebb T1 - A framework to compute resonances arising from multiple scattering JF - Adv. Theory Simul. Y1 - 2025 U6 - https://doi.org/10.1002/adts.202400989 VL - 8 SP - 2400989 ER - TY - JOUR A1 - Jäger, Klaus A1 - Tejada, Alvarjo A1 - Berwig, Sebastian A1 - Hammerschmidt, Martin A1 - Tockhorn, Philipp A1 - Albrecht, Steve A1 - Becker, Christiane T1 - Optical Simulations of Nanotextured All-Perovskite Tandem Solar Cells JF - Adv. Theory Simul. Y1 - 2025 U6 - https://doi.org/10.1002/adts.202400724 VL - 8 SP - 2400724 ER - TY - CHAP A1 - Binkowski, Felix A1 - Betz, Fridtjof A1 - Hammerschmidt, Martin A1 - Zschiedrich, Lin A1 - Burger, Sven T1 - Poles and Zeros in Resonant Nano-Photonic Systems T2 - 2024 Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR) Y1 - 2024 U6 - https://doi.org/10.1109/CLEO-PR60912.2024.10676837 ER - TY - CHAP A1 - Jäger, Klaus A1 - Burger, Sven A1 - Aeberhard, Urs A1 - Llado, Esther Alarcon A1 - Bläsi, Benedikt A1 - Ehrler, Bruno A1 - Favre, Wilfried A1 - Fejfar, Antonín A1 - Gageot, Tristan A1 - Gordon, Ivan A1 - Helmers, Henning A1 - Höhn, Oliver A1 - Isabella, Olindo A1 - Jošt, Marko A1 - Ledinský, Martin A1 - Mandal, Jyotirmoy A1 - Manley, Phillip A1 - Munoz, Delfina A1 - Lizcano, Juan Camilo Ortiz A1 - Paetzold, Ulrich W. A1 - Raman, Aaswath P. A1 - Sai, Hitoshi A1 - Saive, Rebecca A1 - Schmid, Martina A1 - Yablonovitch, Eli A1 - Becker, Christiane T1 - A Roadmap on Optics for Terawatt Scale Photovoltaics T2 - Advanced Photonics Congress 2024 Y1 - 2024 U6 - https://doi.org/10.1364/SELED.2024.STu2G.5 SP - STu2G.5 PB - Optica Publishing Group ER - TY - JOUR A1 - Armas, Jay A1 - Merbis, Wout A1 - Meylahn, Janusz M A1 - Rafiee Rad, Soroush A1 - del Razo, Mauricio J T1 - Risk aversion can promote cooperation JF - Journal of Physics: Complexity N2 - Cooperative dynamics are central to our understanding of many phenomena in living and complex systems. However, we lack a universal mechanism to explain the emergence of cooperation. We present a novel framework for modelling social dilemma games with an arbitrary number of players by combining reaction networks, methods from quantum mechanics applied to stochastic complex systems, game theory and stochastic simulations of molecular reactions. Using this framework, we propose a novel and robust mechanism for cooperation based on risk aversion that leads to cooperative behaviour in population games. Rather than individuals seeking to maximise payouts in the long run, individuals seek to obtain a minimum set of resources with a given level of confidence and in a limited time span. We show that this mechanism can lead to the emergence of new equilibria in a range of social dilemma games. Y1 - 2025 U6 - https://doi.org/10.1088/2632-072X/adb234 VL - 6 IS - 1 ER - TY - JOUR A1 - Asadova, Nigar A1 - Achouri, Karim A1 - Arjas, Kristian A1 - Ajuguié, Baptiste A1 - Aydin, Roland A1 - Baron, Alexandre A1 - Beutel, Dominik A1 - Bodermann, Bernd A1 - Boussaoud, Kaoutar A1 - Burger, Sven A1 - Choi, Minseok A1 - Czajkowski, Krzysztof A1 - Evlyukhin, Andrey B. A1 - Fazel-Najafabadi, Atefeh A1 - Fernandez-Corbaton, Ivan A1 - Garg, Puneet A1 - Globosits, David A1 - Hohenester, Ulrich A1 - Kim, Hongyoon A1 - Kim, Seokwoo A1 - Lalanne, Philippe A1 - Le Ru, Eric C. A1 - Meyer, Jörg A1 - Mun, Jungho A1 - Patelli, Lorenzo A1 - Pflug, Lukas A1 - Rockstuhl, Carsten A1 - Rho, Junsuk A1 - Rotter, Stefan A1 - Stout, Brian A1 - Törmä, Päivi A1 - Trigo, Jorge Olmos A1 - Tristram, Frank A1 - Tsitsas, Nikolaos L. A1 - Vallée, Renaud A1 - Vynck, Kevin A1 - Weiss, Thomas A1 - Wiecha, Peter A1 - Wriedt, Thomas A1 - Yannopapas, Vassilios A1 - Yurkin, Maxim A. A1 - Zouros, Grigorios P. T1 - T-matrix representation of optical scattering response: Suggestion for a data format JF - J. Quant. Spectrosc. Radiat. Transf. Y1 - 2025 U6 - https://doi.org/10.1016/j.jqsrt.2024.109310 VL - 333 SP - 109310 ER - TY - JOUR A1 - Roche, Léo J. A1 - Betz, Fridtjof A1 - Yang, Yuhui A1 - Limame, Imad A1 - Shih, Ching-Wen A1 - Burger, Sven A1 - Reitzenstein, Stephan T1 - Numerical Investigation of a Coupled Micropillar - Waveguide System for Integrated Quantum Photonic Circuits JF - Adv. Quantum Technol. Y1 - 2024 U6 - https://doi.org/10.1002/qute.202400195 VL - 7 SP - 2400195 ER - TY - JOUR A1 - Binkowski, Felix A1 - Burger, Sven A1 - Kewes, Günter T1 - A tiny Drude scatterer can accurately model a coherent emitter in nanophotonics JF - Nanophotonics Y1 - 2024 U6 - https://doi.org/10.1515/nanoph-2024-0170 VL - 13 SP - 4537 ER - TY - JOUR A1 - Berns, Manon A1 - Yildiz, Mirza A1 - Winkelmann, Stefanie A1 - Walter, Alexander T1 - Independently engaging protein tethers of different length enhance synaptic vesicle trafficking to the plasma membrane JF - The Journal of Physiology N2 - Synaptic vesicle (SV) trafficking toward the plasma membrane (PM) and subsequent SV maturation are essential for neurotransmitter release. These processes, including SV docking and priming, are coordinated by various proteins, such as SNAREs, Munc13, and Synaptotagmin (Syt), which connect—tether—the SV to the PM. Here, we investigated how tethers of varying lengths mediate SV docking using a simplified mathematical model. The heights of the three tether types—estimated from the structures of the SNARE complex, Munc13, and Syt—defined the SV-to-PM distance ranges for tether formation. Geometric considerations linked SV-to-PM distances to the probability and rate of tether formation. We assumed that SV tethering constrains SV motility and that multiple tethers associate by independent interactions. The model predicted that forming multiple tethers favors shorter SV-to-PM distances. Although tethers acted independently in the model, their geometrical properties often caused sequential assembly, from longer ones (Munc13/Syt), that accelerated SV movement towards the PM, to shorter ones (SNAREs) which stabilized PM-proximal SVs. Modifying tether lengths or numbers affected SV trafficking. The independent implementation of tethering proteins enabled their selective removal to mimic gene knockout situations. This showed that simulated SV-to-PM distance distributions qualitatively aligned with published EM studies upon removal of SNARE and Syt tethers, while Munc13 knockout data were best approximated when assuming additional disruption of SNARE tethers. Thus, while salient features of SV docking can be accounted for by independent tethering alone, our results suggest that functional tether interactions not yet featured in our model are crucial for biological function. Y1 - 2025 U6 - https://doi.org/10.1113/JP286651 VL - 603 IS - 20 SP - 6107 EP - 6134 ER - TY - GEN A1 - Binkowski, Felix A1 - Betz, Fridtjof A1 - Hammerschmidt, Martin A1 - Zschiedrich, Lin A1 - Burger, Sven T1 - Source code and simulation results: Resonance modes in microstructured photonic waveguides - Efficient and accurate computation based on AAA rational approximation T2 - Zenodo Y1 - 2024 U6 - https://doi.org/10.5281/zenodo.14202408 SP - doi: 10.5281/zenodo.14202408 ER - TY - JOUR A1 - Becks, Henrik A1 - Lippold, Lukas A1 - Winkler, Paul A1 - Rohrer, Maximilian A1 - Leusmann, Thorsten A1 - Anton, David A1 - Sprenger, Bjarne A1 - Kähler, Philipp A1 - Rudenko, Iryna A1 - Andrés Arcones, Daniel A1 - Koutsourelakis, Phaedon-Stelios A1 - Unger, Jörg F. A1 - Weiser, Martin A1 - Petryna, Yuri A1 - Schnellenbach-Held, Martina A1 - Lowke, Dirk A1 - Wessels, Henning A1 - Lenzen, Armin A1 - Zabel, Volkmar A1 - Könke, Carsten A1 - Claßen, Martin A1 - Hegger, Josef T1 - Neuartige Konzepte für die Zustandsüberwachung und -analyse von Brückenbauwerken – Einblicke in das Forschungsvorhaben SPP100+ JF - Bauingenieur N2 - Die Brückeninfrastruktur in Deutschland und Europa steht aufgrund steigender Verkehrslasten und alternder Bauwerke vor erheblichen Herausforderungen. Das DFG-Schwerpunktprogramm 2388 „Hundert plus – Verlängerung der Lebensdauer komplexer Baustrukturen durch intelligente Digitalisierung“ (SPP100+) strebt an, durch digitale Innovationen und prädiktive Instandhaltungsstrategien die Nutzungsdauer bestehender Brückenbauwerke zu verlängern. Der vorliegende Beitrag fokussiert sich auf das SPP100+ zugehörige Cluster „Monitoring und Simulation“, das sieben Teilprojekte umfasst. Die Projekte entwickeln fortschrittliche Methoden zur Überwachung und Zustandsbewertung von Brücken mittels Digitaler Zwillinge, hochauflösender Sensortechnik und numerischer Simulationen. Innovative Ansätze wie nichtlineare Modellanpassungen, stochastische Methoden und künstliche Intelligenz ermöglichen eine präzise und frühzeitige Identifizierung potenzieller Schäden. Die Kombination aus kontinuierlichem Bauwerksmonitoring und effizienter Datenauswertung ist entscheidend für die langfristige Sicherheit und Langlebigkeit bestehender Brücken und trägt darüber hinaus zur Ressourcenschonung bei. N2 - Bridges in Germany and across Europe face significant challenges due to increasing traffic loads and aging structures. The DFG Priority Programme 2388 “Hundred Plus – Extending the Lifetime of Complex Engineering Structures through Intelligent Digitalization” (SPP100+) aims to extend the lifespan of existing bridge structures through digital innovations and predictive maintenance strategies. This paper focuses on the SPP100+ affiliated cluster “Monitoring and Simulation,” which encompasses seven sub-projects. These projects develop advanced methods for monitoring and assessing the condition of bridge structures using digital twins, high-resolution sensor technology, and numerical simulations. Innovative approaches such as nonlinear model adjustments, stochastic methods, and artificial intelligence facilitate precise and early identification of potential damages. The combination of continuous structural monitoring and efficient data evaluation is crucial for the long-term reliability and durability of existing bridges and contributes to resource conservation. T2 - Novel Concepts for the Condition Monitoring and Analysis of Bridge Structures – Insights into the SPP100+ Research Project Y1 - 2024 U6 - https://doi.org/10.37544/0005-6650-2024-10-63 VL - 99 IS - 10 SP - 327 EP - 338 ER - TY - JOUR A1 - Göbel, Fritz A1 - Huynh, Ngoc Mai Monica A1 - Chegini, Fatemeh A1 - Pavarino, Luca A1 - Weiser, Martin A1 - Scacchi, Simone A1 - Anzt, Hartwig T1 - A BDDC Preconditioner for the Cardiac EMI Model in three Dimensions JF - SIAM J. Sci. Comput. N2 - We analyze a Balancing Domain Decomposition by Constraints (BDDC) preconditioner for the solution of three dimensional composite Discontinuous Galerkin discretizations of reaction-diffusion systems of ordinary and partial differential equations arising in cardiac cell-by-cell models like the Extracellular space, Membrane and Intracellular space (EMI) Model. These microscopic models are essential for the understanding of events in aging and structurally diseased hearts which macroscopic models relying on homogenized descriptions of the cardiac tissue, like Monodomain and Bidomain models, fail to adequately represent. The modeling of each individual cardiac cell results in discontinuous global solutions across cell boundaries, requiring the careful construction of dual and primal spaces for the BDDC preconditioner. We provide a scalable condition number bound for the precondition operator and validate the theoretical results with extensive numerical experiments. Y1 - 2025 ER - TY - JOUR A1 - Betz, Fridtjof A1 - Binkowski, Felix A1 - Fischbach, Jan David A1 - Feldman, Nick A1 - Zschiedrich, Lin A1 - Rockstuhl, Carsten A1 - Koenderink, A. Femius A1 - Burger, Sven T1 - Uncovering hidden resonances in non-Hermitian systems with scattering thresholds JF - Laser Photonics Rev. Y1 - 2025 U6 - https://doi.org/10.1002/lpor.202500811 VL - 19 SP - e00811 ER - TY - GEN A1 - Betz, Fridtjof A1 - Binkowski, Felix A1 - Fischbach, Jan David A1 - Feldman, Nick A1 - Rockstuhl, Carsten A1 - Koenderink, A. Femius A1 - Burger, Sven T1 - Source code and simulation results: Hidden resonances in non-Hermitian systems with scattering thresholds T2 - Zenodo Y1 - 2025 U6 - https://doi.org/10.5281/zenodo.14651612 SP - doi: 10.5281/zenodo.14651612 ER - TY - JOUR A1 - Mukherjee, Deshabrato A1 - Burger, Sven A1 - Siefke, Thomas A1 - Gour, Jeetendra A1 - Bodermann, Bernd A1 - Petrik, Peter T1 - Spectroscopic Ellipsometry of Plasmonic Gratings─Ideal Parameters for Sensing and Subpicometer Measurement Uncertainty JF - ACS Omega Y1 - 2025 U6 - https://doi.org/10.1021/acsomega.5c00951 VL - 10 IS - 14 SP - 14466 EP - 14473 ER -