Nov 3, 2009 
Prof. Dr. Sergei Pilyugin
(St.Petersburg University) 
Structural stability of diffeomorphisms and shadowing properties 
We will discuss several new results concerning relations between
structural stability, Ωstability, and
some shadowing properties of diffeomorphisms of smooth closed manifolds.
 Variational shadowing property is equivalent to structural stability.
 Lipschitz shadowing property is equivalent to structural stability.
 Lipschitz periodic shadowing property is equivalent to Ωstability.
Some of these results are joint with A. Osipov and S. Tikhomirov.

Nov 10, 2009 
Dr. Laurette Tuckermann (PMMH, ESPCI Paris) 
Turbulentlaminar patterns in plane Couette flow 
The greatest mystery in fluid dynamics is probably transition to turbulence.
The simplest shear flow, plane Couette flow  the flow between parallel
plates moving at different velocities  is linearly stable for all Reynolds
numbers, but nevertheless undergoes sudden transition to 3D turbulence at
Re near 325. At just these Reynolds numbers, it was recently discovered
experimentally at CEASaclay that the flow takes the form of a steady
and regular pattern of wide oblique turbulent and laminar bands.
We have been able to reproduce these remarkable flows in numerical simulations
of the NavierStokes equations. Simulations display a rich variety of variants
of these patterns, including spatiotemporal intermittency, branching and
travelling states, and localized states analogous to spots. Quantitative
analysis of the Reynoldsaveraged equations reveals that both the mean flow
and the turbulent force are centrosymmetric and can be described by only three
trigonometric functions, leading to a model of 6 ODEs. We find that the
transition is best described as a bifurcation in the probability distribution
function of the power spectrum.

SFB 647 
Nov 17, 2009 
Julia Ehrt (WIAS / FU Berlin) 
Promotionsvortrag / Dissertation Defense Mathmatics of Cell Motility 
15:15,
Free Unversity Berlin, Room 140, Arnimallee 7 (rear building), 14195 Berlin 
The talk will investigate mathematical and modelling aspects of cell motility.
After giving a brief overview on the biochemical processes of cell motility in general
I will focus on crawling cells.
The different processes involved in crawling cells have posed challenging problems in terms of
their physical and chemical background. In addition crawling cells pose a rich field in terms of
mathematical modelling.
Several aspects of the physical and chemical background and the difficulties in modeling these will be
adressed in the talk.
In the last part I will present a very recent model investigated by Gholami, Falcke and Frey (2008)
in which interesting mathematical questions arise.
I will explain the model and investigate its mathematical background.

Nov 24, 2009 
Dr. Nikolay Zhuravlev (Peoples' Friendship University of Russia) 
Methoden zur qualitativen Untersuchung periodischer Lösungen von
Funktionaldifferentialgleichungen 
Die Eigenwerte des MonodromieOperators beschreiben das Verhalten der
Trajektorien in der Naehe einer periodischen Loesung. Im Gegensatz zu
gewoehnlichen Differentialgleichungen fuehren
Funktionaldifferentialgleichungen jedoch auf Operatoren zwischen
unendlichdimensionalen Raeumen. Es ist daher viel schwieriger, die
Eigenwerte des MonodromieOperators zu bestimmen.
Im Vortrag werde ich ueber Methoden zur Bestimmung dieser Eigenwerte
berichten.

Dec 1, 2009 
SFB 647 
Dec 8, 2009 
Dr. Georgy Kitavtsev (WIAS Berlin) 
Reduced ODE models describing coarsening dynamics of slipping droplets 
In this talk the topic of reduced ODE models corresponding to a family of onedimensional
lubrication equations derived by M"unch et al. '06 is addressed.
This family describes the dewetting process of nanoscopic thin liquid ?lms on hydrophobized
polymer substrates due to the presence of several intermolecular forces and takes
account of different ranges of sliplengths at the polymer substrate interface. Reduced
ODE models derived from underlying lubrication equations allow for an efficient analytical
and numerical investigation of the latest stage of the dewetting process: coarsening
dynamics of the remaining droplets. We present a new geometric approach which can
be used for an alternative derivation and justi?cation of above reduced ODE models
and is based on a centermanifold reduction recently applied by Mielke and Zelik '08
to a certain class of semilinear parabolic equations. One of the main problems for
a rigorous justi?cation of this approach is investigation of the spectrum of a lubrication
equation linearized at the stationary solution, which describes physically a single
droplet. The corresponding eigenvalue problem turns out to be a singularly perturbed
one with respect to a small parameter ε tending to zero. For this problem we show existence
of an εdependent spectral gap between a unique exponentially small eigenvalue
and the rest of the spectrum.

Dec 15, 2009 
SFB 647 
Jan 12, 2010 
SFB 647 
Jan 26, 2010 
Prof.Dr. Sergei Shapiro
(Freie Universität Berlin, FR Geophysik) 
Fluidinduced seismicity and porepressure diffusion in rocks 
Dr. Marc Timme
(MPI Dynamics&Selforganization, Göttingen) 
SpatioTemporal Patterns in the Brain: Neural Networks with Nonlinear Dendrites 
Feb 2, 2010 
Prof. Dr. Flavio Abdenur (PUC, Rio de Janeiro) 
Geometric mechanisms for robust transitivity 
14:15,
Free Unversity Berlin, Room 140, Arnimallee 7 (rear building), 14195 Berlin 
The existence of robustly transitive but nonAnosov
diffeomorphisms has been known ever since Shub's construction in the
early seventies. In the past 15 years or so, new examples have been
given, many of which rely on the blender studied by Diaz and Bonatti. In
addition, for the first time general necessary properties of such
systems have been obtained: "robust transitivity implies suchandsuch a
condition". In this talk I will briefly survey the literature and then
discuss some ongoing work that goes in the opposite direction: we ask
which conditions are sufficient for  and hopefully in some sense
characterize  the phenomenon of robust transitivity. This involves
ongoing joint work with S. Crovisier.

SFB 647 
Feb 9, 2010 
Dr. Przemyslaw Perlikowski
(Technical University of Lodz) 
Dynamics in a ring of delayed coupled StuartLandau oscillators 
Results presented in the talk consider the ring of unidirectionally
delayed coupled StuartLandau oscillators. Firstly, we show
investigations of steady state stability, we present its properties with
respect to delay in coupling and number of oscillators in the ring. To
cope with small and large delay in the coupling we applied analytical
techniques, while for intermediate delay we use Lambert function. Then, we
present the influence of time delay and size of the ring on appearance of
periodic solutions. We find coexisting stable periodic solutions (here,
rotating waves), which correspond to Eckhaus instability. Presented
results are ongoing joint work with S. Yanchuk.
