Oberseminar "Dynamische Systeme" (WiSe 2016/2017; Oktober-März)

Das Oberseminar findet üblicherweise dienstags 14:00-15:30 Uhr im Raum A3.339 statt.   

Nächster Vortrag:

Dienstag, 07. Februar 2017;  16:15 - 17:45 in D2.314

Achtung!!! Bitte die geänderte Vortragszeit und Ort beachten.

Vortragender: Karin Mora

Titel: Koopman operator based time series analysis of electroencephalography (EEG) data

Abstract: The Koopman operator and its numerical approximation via dynamic mode decomposition (DMD) will be reviewed.

We will discuss how DMD can be applied to analyse large scale data such as electroencephalographic (EEG) data, which are time series of neural activity recorded by 10s of electrodes over several minutes. We will demonstrate how DMD can capture the spatio-temporal dynamics of EEG data and discuss how these results can be interpreted to unterstand neural dynamics.

Dienstag, 8. November 2016;  14:00 - 15:30 in A3.339

Vortragender: Thomasz Luks (Uni-Paderborn)

Titel: On the generator of a killed Feller process

Abstract: The aim of the talk is to characterize the generator of the semigroup associated with a Feller process killed upon leaving a regular bounded domain in Euclidean space. The presented methods work under the assumption that the semigroup of the free process is strong Feller. We will also discuss applications to fractional Cauchy problems on bounded domains.

Dienstag, 15. November 2016;  14:00 - 15:30 in A3.339

Vortragender: Joachim Hilgert (Uni-Paderborn)

Titel: Geodätische und Weylkammer Flüsse - klassisch und quantisiert

Dienstag, 22. November 2016;  14:00 - 15:30 in A3.339

Voraussichtlich kein Seminarvortrag

Dienstag, 29. November 2016;  14:00 - 15:30 in A3.339

Vortragender: Barbara Gentz (Uni Bielefeld)

Titel: Synchronization in coupled stochastic systems

Abstract: I will give an overview of various aspects of metastability in reversible and irreversible stochastic systems. These studies are motivated by questions regarding the effect of noise on synchronization in systems of coupled identical as well as non-identical dynamical systems.

Joint work with Nils Berglund (Universit\’e d’Orl\'eans, France) , Bastien Fernandez (Universit\'e Paris Diderot, France) and with Seung-Yeal Ha (Seoul National University, South Korea), Dongnam Ko (Seoul National University, South Korea) and Christian Wiesel (University of Bielefeld, Germany).

Dienstag, 06. Dezember 2016;  14:00 - 15:30 in A3.339

Vortragender: Maik Gröger (Uni Jena)

Titel: Topological invariants in the zero entropy regime

Abstract: We will start by reviewing the basic definition and properties of topological entropy for discrete dynamical systems. Afterwards, we introduce two complexity notions in the zero entropy regime: mean equicontinuity and amorphic complexity. As it turns out, there is a close relationship in the minimal setting and we present some results highlighting their interplay. Further, as one application, we demonstrate how amorphic complexity can help to detect non-smooth saddle-node bifurcations in quasiperiodically forced systems. If time permits, we will elaborate on a geometric point of view towards amorphic complexity for low-complexity subshifts. This is work in progress with Gabriel Fuhrmann, Tobias Jäger and Dominik Kwietniak.

Dienstag, 13. Dezember 2016;  14:00 - 15:30 in A3.339

Vortragender: Sonja Barkhofen (Uni Paderborn - AG Integrated Quantum Optics)

Titel: Quantum walks in time

Abstract: In this talk we will discuss what a quantum walk is and how it can be experimentally realized using time multiplexing techniques.

Dienstag, 10. Januar 2017;  14:00 - 15:30 in A3.339

Vortragender: Helge Glöckner (Uni Paderborn)

Titel: Konvergenz von Bahnen gegen kompakte Mengen und Anwendungen im Bereich lokal kompakter Gruppen

Abstract: In jedem uniformen Raum X ist es möglich, über Konvergenz von Folgen (und Netzen) gegen eine Teilmenge K von X zu sprechen. Im allgemeinbildenden ersten Teil des Vortrags werden dieser Begriff und einige ihn betreffende nützliche Aussagen erläutert (insb. über die Konvergenz von Bahnen f^n(x) gegen eine kompakte Menge K).

Im zweiten Teil des Vortrags ist f ein Endomorphismus einer lokal kompakten topologischen Gruppe G. Im Falle, dass G total unzusammenhängend ist, kann das dynamische System (G,f) mit Methoden der 1994 von George A. Willis angestoßenen Strukturtheorie total unzusammenhängender Gruppen untersucht werden. Als Spezialfall von Konvergenz gegen Teilmengen wird u.a. ein Resultat über Konvergenz gegen f-invariante abgeschlossene Untergruppen vorgestellt.

(Gemeinsame Forschung mit T.P. Bywaters und S. Tornier)

Dienstag, 17. Januar 2017;  14:00 - 15:30 in A3.339

Vortragender: Michael Winkler (Uni Paderborn)

Titel: Wachstumsphänomene in logistischen Chemotaxissystemen

Dienstag, 24. Januar 2017;  14:00 - 15:30 in A3.339

Vortragender: Daniel Lenz (Uni Jena)

Titel: Aperiodic order and pure point diffraction

Dienstag, 31. Januar 2017;  14:00 - 15:30 in A3.339

Vortragender: Adrian Zeissler (Uni Paderborn)

Titel:  On the Computation of Attractors for Delay Differential Equations and Partial Differential Equations

Abstract: In this talk we will introduce a numerical method which
allows to approximate (low dimensional) invariant sets for
infinite dimensional dynamical systems. We will focus on the computation of attractors
for delay differential equations and partial differential equations.
The numerical approach is inherently set oriented - that is,
the invariant sets are computed by a sequence of nested,
increasingly refined approximations -, and does not rely on long term
simulations of the underlying system.

Dienstag, 07. Februar 2017;  16:15 - 17:45 in D2.314

Achtung!!! Bitte die geänderte Vortragszeit und Ort beachten.

Vortragender: Karin Mora

Titel: Koopman operator based time series analysis of electroencephalography (EEG) data

Abstract: The Koopman operator and its numerical approximation via dynamic mode decomposition (DMD) will be reviewed.

We will discuss how DMD can be applied to analyse large scale data such as electroencephalographic (EEG) data, which are time series of neural activity recorded by 10s of electrodes over several minutes. We will demonstrate how DMD can capture the spatio-temporal dynamics of EEG data and discuss how these results can be interpreted to unterstand neural dynamics.