Alessandro Moirano (LPAP, ULiège)
2025-10-16 13:00 - 14:00 (Europe/Brussels)
Title: Io, a natural probe for Jupiter’s atmosphere and magnetosphere – (Some of) Juno’s results on the moon-magnetosphere interaction.
Abstract:

Jupiter hosts persistent and bright auroras, which are driven by the precipitation of particles into its atmosphere, mostly electrons. The presence of Io orbiting in the inner Jovian magnetosphere produce a specific auroral emission on Jupiter, called “footprint”, whose details are determined by the atmosphere and the energy of the precipitating electrons. The latter, in turn, depends on the physical magnetospheric process(es) that accelerates the particles along the magnetic field and towards the planet. Therefore, the footprint – and the aurora in general – wraps information about the atmospheric structure and the energy spectrum of the precipitation. During this talk, we will discuss the recent analyses of the observations performed by Juno, which has been orbiting Jupiter and providing an unprecedented vantage point on its polar regions since 2016. To begin with, the position of the Io footprint is affected by the Io plasma torus, a dense and variable plasma cloud around Io’s orbit that is ultimately produced by the volcanic activity on the moon. We were able to constrain the spatial distribution of plasma near Io thanks to several years of observations with Juno. Moreover, during some of the closest-approach to Jupiter, Juno was able to observe the Io footprint near the planetary limb, which provided a unique opportunity to investigate the relation between the spectrum of the precipitating electrons and the vertical profile of the auroral emission. Lastly, by looking at the absorption in the far-ultraviolet recorded with the Ultraviolet Spectrograph onboard Juno, we aim at estimating the hydrocarbon abundances in the upper layers of Jupiter’s atmosphere.

The seminar mostly presents results driven by observations, interpreted in light of current theoretical models. Infrared, ultraviolet and radio observations, as well as in-situ particle measurements, are the backbone of the talk, although the moon-magnetosphere interaction welcome all types of expertise and observations.

This seminar will take place in Room S08 at the Faculty of Sciences.

Isao Ishikawa (Kyoto University)
2025-10-21 13:00 - 14:00
Title: Finite dimensional approximations of push-forwards on analytic functionals
Abstract:
In this talk, we will introduce JetEDMD, a new theoretical framework as a finite-dimensional approximation of the push-forward on the spaces of analytic functionals.
JetEDMD provides a reasonable modification of Extended Dynamic Mode Decomposition (EDMD) and elucidates new mathematical machinery by combining the structure of reproducing kernel Hilbert spaces with the jet spaces on the state space of the dynamical system.

As applications, I will present methods for the data-driven estimation of equilibrium points and the reconstruction of vector fields from discrete trajectory data with a rigorous convergence result. Finally, I will discuss some current mathematical challenges and future research directions within this framework.

Laura Gagliardi (University of Chicago)
2025-10-22 15:00 - 16:30
Title: Reticular frameworks after the Nobel prize: their application for catalysis and CO2 capture
Abstract:

Following reflection on the 2025 Nobel Prize in Chemistry awarded for advances in metal– organic frameworks (MOFs), this lecture explores how state-of-the-art quantum chemical and classical simulations are driving the discovery of reticular materials. Computation today is not only a tool to rationalize experiments, but increasingly a predictive engine for tailoring functional frameworks.
In the first part of the presentation, I will highlight our integrated computational and experimental study of catalytic MOFs, where post-synthetic modification introduced metal– sulfur active sites [1]. Quantum chemical calculations elucidated how sulfur incorporation modulates the electronic structure and catalytic reactivity of the frameworks. These insights provided a mechanistic understanding of hydrogenation catalysis and guided the design of MOFs with tunable properties.
The second part will focus on covalent organic frameworks (COFs). Thanks to their modular architectures and tunable functionalities, COFs offer a highly versatile platform for CO2 direct air capture. We performed a multiscale investigation of COF-999 and its amine- functionalized precursor COF-999-NH₂, integrating density functional theory, molecular dynamics, and grand canonical Monte Carlo simulations with experimental validation [2]. Our findings highlight subtle energy differences in laterally shifted stackings, intrinsic stacking heterogeneity, and pronounced layer buckling. We found that extensive amine– nitrile hydrogen bonding and persistent pore water lead to undesired polymerization that undermines CO₂ uptake. The predicted presence of water is confirmed by subsequent experiments. These insights point to a single, actionable design rule: exclude retained water by introducing hydrophobic pore environments to maximize CO2 capture efficiency.
[1] H. Xie, M. A. Khoshooei, M. Mandal, S. M. Vornholt, J. Hofmann, L. M. Tufaro, K. O. Kirlikovali, D. A. Grimes, S. Lee, S. Su, S. Reischauer, D. Sengupta, K. Fahy, K. Ma, X. Wang, F. Sha, W. Gong, Y. Che, J. G. Vitillo, J. S. Anderson, J. M. Notestein, K. W. Chapman, L. Gagliardi, and O. K. Farha, Introducing Metal–Sulfur Active Sites in Metal–Organic Frameworks Via Post-Synthetic Modification for Hydrogenation Catalysis, Nature Chemistry, 2025. DOI: 10.1038/s41557-025-01876-y
[2] H. Daglar, Z. Zhou, R. Zhu, P. Parihar, J. I. Siepmann, O. M. Yaghi, L. Gagliardi Discovery of Stacking Heterogeneity, Layer Buckling, and Residual Water in COF-999-NH₂ and Implications on CO2 Capture Submitted (2025)

This seminar will take place in Room S05 at the Faculty of Sciences.

Serge Nicaise (Université de Valenciennes)
2025-11-27 13:00 - 14:00
Title: Stability results of dissipative systems via the frequency domain approach
Abstract:

The frequency domain approach goes back to J. Prüss [Trans. Amer. Math. Soc. 284 (1984), 847-857] and F. L. Huang [Ann. Differential Equations 1 (1985), 43-56] that show that a C0 semigroup (etA)t≥0 of contractions in a Hilbert space H is exponentially stable if and only if the resolvent of A is uniformly bounded on the imaginary axis. Afterwards Z. Liu and B. Rao, [Z. Angew. Math. Phys. 56 (2005), 630-644], C. J. K. Batty and T. Duyckaerts [J. Evol. Equ. 8 (2008), 765-780], and A. Bátkai, K.-J. Engel, J. Prüss and R. Schnaubelt [Math. Nachr. 279 (2006), 1425-1440] have given some sufficient conditions on the behavior of the resolvent of A on the imaginary axis that guarantee an almost polynomial decay of the semigroup. Finally an optimal result about the polynomial decay was found by A. A. Borichev and Yu. V. Tomilov [Math. Ann. 347 (2010), 455-478]. This approach is a powerful tool for the study of the decay of the semigroup associated with concrete dissipative systems since it reduces to the study of the resolvent on the imaginary axis.
In my talk, I will first recall these two results and then illustrate them on two particular dissipative systems.

This seminar will take place in Room S08 at the Faculty of Sciences.

session pitch naXys
2026-01-29 13:00 - 14:00
“Coexistence and stability in ecological systems” (Frederik De Laender)
“Measuring and implementing sustainability in finance: The need for systemic approaches” (Sophie Béreau)
“Analysis of the control system mechanisms of robots” (Elio Tuci)
“Rare trajectories in quantum field theory and classical dynamics” (Yves Caudano)
“Emergent properties of complex systems. A tale of networks and nonlinearity” (Timoteo Carletti)
This seminar will take place in Room S09 at the Faculty of Sciences.

Diego Samuel Rodrigues (University of Campinas, SP, Brazil)
2026-02-11 13:00 - 14:00
Title: Parameter Estimation for Ordinary Differential Equation Models in Cancer Research
Abstract:
Inferring parameter values from data is a fundamental problem in quantitative oncology. This seminar offers a concise, example-driven overview of parameter estimation and experimental design for ordinary differential equation systems, bridging theoretical foundations with practical applications in cancer research.

This seminar will take place in Room S0 at the Faculty of Sciences.

Federica Garin (Université Grenoble Alpes)
2026-02-26 13:00 - 14:00
Title: Graphons and opinion dynamics on large graphs.
Abstract:
Graphons are the limits of large dense graphs. Graphons can also be used to define families of random graphs (the so-called W-random graphs), similar to Erdős-Rényi random graphs but with some inhomogeneity in the edge probabilities.
Graphons and W-random graphs, together with their signed counterparts, can be useful tools to study opinion dynamics on large-scale networks.
In this talk, I will review some recent work in this direction, where we explore some infinite-dimensional dynamics associated with the graphon, and we study how well they can approximate the corresponding dynamics associated with finite but large W-random graphs.

This seminar will take place in Room S08 at the Faculty of Sciences.

Harry Shaw (Xyngal Morph)
2026-04-27 13:00 - 14:00
Title: Overview of quantum chemistry investigations into classically studied materials with potentially useful quantum properties
Authors: Harry Shaw1, Deborah Preston1, Virginia Ayres2, Kyle Sherbert3, Naveed Naimipour4, Nick Savino6, Manon Bart5, Ryan Glasser6
(1) Xyngal Morph LLC, Bel Air, MD
(2) Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, USA
(3) Department of Computer Science, Holy Cross University, Notre Dame, IN, USA
(4) Engineering Faculty, Wilbur Wright College, Chicago, IL
(5) Namur Institute for Complex Systems, University of Namur, Namur, Belgium
(6) School of Science and Engineering, Tulane University, New Orleans, LA, USA
Abstract:
While at NASA Goddard Space Flight Center, several investigations were conducted to take materials that were well characterized in the classical domain to determine if they could be utilized in what can be called the “quantum domain”. Of special interest were radiation effects on GaN nanowires1, flying qubit investigations2, and tautomers which could be utilized in a variety of quantum circuits. The tautomer investigations were performed on cis- and trans-azobenzene and the proton tautomer croconic acid. Also of interest are the cyclopentadienyls Bis(cyclopentadienyl)cobalt(II) and Bis(cyclopentadienyl)iron with properties that could make them good candidates for spintronic applications3. In this talk we will discuss some aspects of these investigations including our use of Density Functional Theory (DFT) tools4.
NASA’s interest lies in how these materials could be used in systems for quantum communications, computing or other useful applications. Most of this research was conducted by graduate students and faculty associated with our NASA internships. Additional parallel research paths included development of optical angular momentum (OAM) capabilities, quantum entanglement, optical neural networks5, and quantum compressive sensing6.

Jacobs, B. W., V. M. Ayres, R. M. Ronningen, A. F. Zeller, E. H. Carey, M. A. Crimp, M. P. Petkov, S.L. Rutledge , J.B. Benavides, H.C. Shaw et al. “Heavy Ion Interactions with Nanotubes and Nanowires.” In APS March Meeting Abstracts, vol. 1, p. 1163. 2006.
Dong, H., Panda, G., Xie, K., Ayres, V., Shaw, H., Preston, D., & Deshpande, M. (2017). Flying qubit investigations for heterostructure-based qubit implementations. In 2017 IEEE 17th International Conference on Nanotechnology, NANO 2017 (pp. 636-640).
Leber, Roland. Growth and Characterisation of Metallocene Based Thin Films for Spintronic Applications. Diss. UCL (University College London), 2018.
https://www.scm.com/amsterdam-modeling-suite/adf
Bart M, Savino NJ, Regmi P, Cohen L, Safavi H, Shaw H, Lohani S, Searles TA, Kirby BT, Lee H, Glasser RT. Deep learning for enhanced free-space optical communications. Machine Learning: Science and Technology. 2022.
Sherbert, Kyle M., Naveed Naimipour, Haleh Safavi, Harry C. Shaw, and Mojtaba Soltanalian. “Quantum Compressive Sensing: Mathematical Machinery, Quantum Algorithms, and Quantum Circuitry.” Applied Sciences 12, no. 15 (2022): 7525.https://www.mdpi.com/2076-3417/12/15/7525

This seminar will take place in Room S09 at the Faculty of Sciences.

Koichiro Yawata (Institute of Science, Tokyo)
2026-05-07 13:00 - 14:00
Title: Reduced-Order Control of Coupled Phase Oscillator Populations and Hypergraph-Based Approaches to Combinatorial Optimization Problems

Abstract:
In this seminar, I will present two recent pieces of work from my research: one on reduced-order control of coupled oscillator populations and another on hypergraph-based approaches to combinatorial optimization.
1. Reduced-Order Control of Coupled Oscillator Populations via Frequency-Dependent Forcing
We propose a frequency-dependent forcing framework for heterogeneous populations of coupled phase oscillators. Using the Ott-Antonsen ansatz, we derive a low-dimensional description of the collective dynamics and study control methods for the macroscopic phase and synchronization level.
2. Hypergraph Neural Networks Accelerate MUS Enumeration
We propose a hypergraph-neural-network-based method for accelerating MUS enumeration in constraint satisfaction problems. By combining hypergraph modeling with reinforcement learning, the method reduces satisfiability checks and improves enumeration efficiency.
This seminar will take place in Room S08 at the Faculty of Sciences.

Sandrine Ngamga (Université de Dschang, Cameroun)
2026-05-28 13:00 - 14:00
Title: The chimera states in a network of Huygens pendulums examined with Gopal’s indices and recurrence analysis
Abstract:
Chimera states, defined by the coexistence of coherent and incoherent domains in coupled oscillator networks, arise in a wide variety of systems and play a key role in understanding symmetry breaking, partial synchronisation, and stability in extended dynamical networks. Their emergence has been widely reported in chemical, biological, and electronic systems, but remains far less explored in purely mechanical oscillators, despite their relevance for structural dynamics, robotic assemblies and mechanical metamaterials. In this work, we investigate the collective behaviour of a one-dimensional network of self-sustained Huygens pendulums and demonstrate the emergence of several chimera regimes. Besides classical chimera and multi- chimera patterns, we identify three additional forms : (i) a Quasi-Coherent Chimera, where a weakly perturbed coherent domain coexists with a highly agitated incoherent region; (ii) a Multi-Cluster Chimera, consisting of several coherent clusters separated by incoherent bands ; and (iii) a new EvenOdd Structured Chimera, in which coherent oscillators form two interlaced spatial clusters. This last state cannot be detected by the standard Gopal indicators : the Strength of Incoherence (S) and the Discontinuity Measure (DM) because their nearest-neighbour formulation suppresses the evenodd alternation. To overcome this limitation, we propose a modified version of Gopals indices, which successfully identifies the EvenOdd Structured Chimera. Independent validation using Recurrence Quantification Analysis (RQA) to confirm the coherent and incoherent organisation for all chimera types. These results show that mechanical oscillator networks can host an unexpectedly rich variety of chimera states, and that combining modified local indicators with recurrence-based diagnostics provides a robust framework for detecting both standard and highly structured chimera patterns.
This seminar will take place in Room S08 at the Faculty of Sciences.

Francesco Ferranti (Luleå University of Technology)
2026-06-08 13:00 - 14:00
Title: Artificial Intelligence-based Design, Multiscale Simulations, Advanced Characterization and Monitoring for Complex Physical Systems
Abstract:
Recent advances in artificial intelligence (AI) are opening new significant opportunities for the design, modeling, and operation of complex physical systems as next-generation electromagnetic and electronic systems in applications as communications, computing, sensing, and imaging. This seminar will present research results on AI techniques for electromagnetic design, with applications as metasurfaces, defective ground plane filters, and THz sensors. These techniques allow exploring a large variety of layouts and build models that can be used for efficient and accurate design tasks (e.g., optimization and uncertainty quantification tasks). Some results where physical insight and equivalent circuits representations are used instead of more general black-box descriptions will be shown. Connections with topics as system identification, surrogate modeling, and model order reductions, and physical properties of dynamical systems as causality, stability, and passivity will be illustrated.
The seminar will also present multiscale simulation and design methodologies, focusing on hybrid approaches that combine full-wave electromagnetic solvers with ray-tracing techniques. Such methods are particularly relevant for the design and analysis of metalenses and metasurface-enabled propagation environments, where accurate local electromagnetic modeling must be integrated with large-scale wave propagation analysis. Applications of metasurfaces in fluorescence endoscopy imaging and lab brain tissue validation will be shown.
Finally, the seminar will also discuss automated characterization and monitoring techniques for complex physical systems, including compressed-sensing-based fault identification in antenna arrays, embedded element pattern characterization methods, and adaptive behavioral modeling of power amplifiers from selectively acquired measurement data. AI approaches for electromagnetic spectrum anomaly detection and spectrum intelligence, and hardware-software codesign will also be briefly addressed.
This seminar will take place in Room S09 at the Faculty of Sciences.

Geza Mark (Centre for Energy Research, University of Budapest).
2026-07-02 13:00 - 14:00
Titre : Information, energy, and entropy — what is the price of knowledge?
Abstract :
Global energy consumption of artificial intelligence already has reached the total electricity consumption of a medium-sized country. Hence, it is timely to look at this question from the viewpoint of physics. First we ask whether there is a theoretical minimum of energy needed for information processing. Then, we investigate, how far are the AI systems from that limit and compare this to biological systems. Finally, we explore the theoretical possibilities for increasing energy efficiency and discuss which of these are technologically feasible in the near future.
This seminar will take place in Room CH11 at the Faculty of Sciences.

Serge Richard (Nagoya University)
2026-09-14 13:00 - 14:00
Title:
Abstract:
This seminar will take place in Room S08 at the Faculty of Sciences.

Nelly Litvak (Eindhoven University of Technology)
2026-10-01 13:00 - 14:00
