| Oct 17, 2013 |
Isabelle Schneider and Matthias Bosewitz
(Free University Berlin) |
Time-delayed feedback control design beyond the odd-number limitation |
|
We present a recent paper by K. Pyragas and V. Novicenko where they
discuss necessary conditions for successful Pyragas control.
The publication continues Hooton and Amann's work on a new odd-number
limitation for autonomous dynamical systems.
The main tool is the comparison of proportional with time-delayed feedback
control.
|
| Oct 24, 2013 |
Jia-Yuan Dai
(Free University Berlin) |
Existence of spiral ansatz for the complex Ginzburg-Landau equation |
|
The purpose of this talk is to find a suitable spiral ansatz for
the complex Ginzburg-Landau equation (CGLe) and solve for it.
Firstly a proof for existence of a spiral ansatz based on the work
of N. Kopell and L. Howard (1981) and J. Greenberg (1982) is
presented, and then a spiral ansatz on a sphere, which reduces the
CGLe into a non-autonomous ODE system with singularities at
north/south poles, is posed and discussed.
|
| Oct 31, 2013 |
Bernhard Brehm
(Free University Berlin) |
Shadowing based analysis of Bianchi 9 vacuum dynamics |
|
Since I have over the years given several talks about Bianchi in
the internal seminar, I should provide some context for this talk.
I claimed several ``trivial'' qualitative results on Bianchi,
which ``ought to be folklore'' and which provide much needed
context and motivation for the hard analysis style estimates which
I am pursuing.
These qualitative results turned out to be not quite as trivial as
I had claimed and seem to be not covered in the previous
literature. Combined with the usual mission creep found in any
study, this let the qualitative shadowing based analysis of
Bianchi dynamics grow to its own project, the first fruit of which
I am going to present.
|
| Nov 7, 2013 |
Phillipo Lappicy
(Free University Berlin) |
Einstein equations and the black hole problem |
|
In this talk I'll present an overview of the Einstein equations
and provide ideas to show its well-posedness. Lastly, I'll state
the black hole initial data problem and how to tackle it.
|
| Nov 21, 2013 |
Antonio Politi
(University of Aberdeen, UK) |
Coarsening processes in Discrete Nonlinear Schroedinger-type models |
|
The Discrete Nonlinear Schroedinger equation (DNLSE) is a
paradigmatic model used to describe both Bose-Einstein condensates
and propagation in waveguides. The DNLSE behaviour is discussed
from the point of view of statistical mechanics, with a particular
emphasis given to the convergence to the equilibrium state in the
regime of the so-called negative (absolute) temperatures. The
observed coarsening is studied with the help of simplified models
of exclusion-process type.
|
| Nov 21, 2013 |
Stefan Liebscher
(Free University Berlin) |
Geometries of the projective plane |
|
The projective space provides a unified approach to different types of geometries.
This can be a great help to our intuition when dealing with problems in
(differential) geometry beyond tensor algebra. In this talk with computer experiments
I will introduce some of the features of the projective plane and discuss
connections to geodesic flows and parallel transport.
|
| Dec 5, 2013 |
Juliette Hell
(Free University Berlin) |
Bistability for MAPkinase dual futile cycle |
|
This is a joint work with Alan Rendall.
MAPkinase plays an
important role in cell signaling. It is a proteine that undergoes
a cascade of phosphorylations. One level of this cascade consists
of the dual futile cycle. We prove bistability in the dual futile
cycle via cusp-bifurcation both for the
Michaelis-Menten-via-mass-action model (MMMA), where enzymes are
explicitly included, and the Michaelis-Menten model (MM, which is
a singular limit of the MMMA where enzymes are simplified away).
This is the first step in order to prove relaxation-oscillations
in the complete cascade.
|
| Dec 12, 2013 |
Atsushi Mochizuki, Bernold Fiedler
(RIKEN, Tokyo; Free University Berlin) |
Rate sensitivity analysis of chemical reaction networks: a public discussion |
|
|
| Jan 30, 2014 |
Mark Curran, Konstantin Bubolz, Anna Karnauhova
(Free University Berlin) |
Ongoing research |
|
|
| Jan 30, 2014 |
Nikita Begun
(Saint-Petersburg State University, Russia) |
Perturbations of attractors |
|
|
| Feb 13, 2014 |
Nikita Begun
(Saint-Petersburg State University, Russia) |
One-dimensional chaos in a system with dry friction |
|
We introduce a new analytical method which allows one to find
chaotic dynamics in non-smooth dynamical systems. A simple
mechanical system consisting of a mass and a dry friction element
is considered as an example. We prove the existence of an infinite
set of periodic points of arbitrarily large periods.
|
| Feb 13, 2014 |
Hannes Stuke
(FU Berlin) |
PDE solutions beyond the blow-up |
|
In this talk I attempt to prove two theorems concerning the
possibility of analytic continuation of PDE solutions after
blow-up:
1. There exists a small neighborhood of the real time axis such
that the solution is analytic up to the blow-up.
2. Under relatively moderate assumptions on the blow-up, it is
possible to analytically continue beyond the blow-up.
If there is still time left, I will outline further results and
research directions arising from an interplay of Hardy space
theory and semigroups.
|
Last change: Feb. 12, 2014
