Informal Seminar

- Past Events


27.01.25	MathRepo: Data for and from your Research At this event MathRepo, the repository for mathematical software run by the institute, will be introduced. Interesting mathematical research data for your own research within the repository will be presented by the contributors. We will look at MathRepo’s structure and functionalities and you will learn how your own data can become part of the repository by being guided through the steps of uploading material. You are welcome to bring your own laptop. If you prepare by following the "Initial Setup"-instructions here, you may find it easier to follow along when we show you how to create a page. This event is organized by Alessio Borzì.

27.01.25

MathRepo: Data for and from your Research

At this event MathRepo, the repository for mathematical software run by the institute, will be introduced. Interesting mathematical research data for your own research within the repository will be presented by the contributors. We will look at MathRepo’s structure and functionalities and you will learn how your own data can become part of the repository by being guided through the steps of uploading material. You are welcome to bring your own laptop. If you prepare by following the "Initial Setup"-instructions here, you may find it easier to follow along when we show you how to create a page. This event is organized by Alessio Borzì.


23.07.21	Connor Mooney (University of California, Irvine) : Singular structures in exterior solutions to the Monge-Ampere equation

23.07.21

Connor Mooney (University of California, Irvine) : Singular structures in exterior solutions to the Monge-Ampere equation


08.05.15	Charles Doering (University of Michigan, Ann Arbor) : Maximal vorticity amplification and enstrophy production in the 3D Navier-Stokes equations It is not known if solutions to the 3D Navier-Stokes equations for incompressible Newtonian fluids flowing in a finite periodic box can become singular in finite time. Indeed, this open issue is the subject of one of the $1M Clay Prize problems. It is known that solutions remains smooth as long as the enstrophy, i.e., the mean-square vorticity in the flow filed, is finite. The instantaneous generation rate of enstrophy is given by a functional that can be bounded in terms of the enstrophy itself using elementary functional estimates. That classical analysis establishes short-time regularity of solutions starting with arbitrarily large (but finite) enstrophy but does not rule out the possibility of singularities subsequently appearing in the flow in finite time. In this work we formulate and solve the variational problem for the maximal growth rate of enstrophy and display flows that saturate the functional analytic estimates and amplify vorticity at the greatest possible rate. Implications for questions of regularity or singularity in solutions of the 3D Navier-Stokes equations are discussed. This joint work with Lu Lu was published in Indiana University Mathematics Journal Vol. 57, pp. 2693-2727 (2008).

08.05.15

Charles Doering (University of Michigan, Ann Arbor) : Maximal vorticity amplification and enstrophy production in the 3D Navier-Stokes equations

It is not known if solutions to the 3D Navier-Stokes equations for incompressible Newtonian fluids flowing in a finite periodic box can become singular in finite time. Indeed, this open issue is the subject of one of the $1M Clay Prize problems. It is known that solutions remains smooth as long as the enstrophy, i.e., the mean-square vorticity in the flow filed, is finite. The instantaneous generation rate of enstrophy is given by a functional that can be bounded in terms of the enstrophy itself using elementary functional estimates. That classical analysis establishes short-time regularity of solutions starting with arbitrarily large (but finite) enstrophy but does not rule out the possibility of singularities subsequently appearing in the flow in finite time. In this work we formulate and solve the variational problem for the maximal growth rate of enstrophy and display flows that saturate the functional analytic estimates and amplify vorticity at the greatest possible rate. Implications for questions of regularity or singularity in solutions of the 3D Navier-Stokes equations are discussed. This joint work with Lu Lu was published in Indiana University Mathematics Journal Vol. 57, pp. 2693-2727 (2008).


05.03.13	Martina Hofmanova (ENS de Cachan) : A kinetic approach to stochastic conservation laws Many basic equations in physiscs can be written in the form of conservation law. However, as it is common in the field of PDEs and SPDEs, classical or strong solutions do not exist in general and, on the other hand, weak solutions are not unique. The notion of kinetic formulation and kinetic solution turns out to be a very convenient tool to overcome these difficulties. In this talk, I will present a well-posedness result for degenerate parabolic stochastic conservation laws and, in the case of hyperbolic stochastic conservation laws, discuss the hydrodynamic limit of an approximation in the sense of Bhatnagar-Gross-Krook.

05.03.13

Martina Hofmanova (ENS de Cachan) : A kinetic approach to stochastic conservation laws

Many basic equations in physiscs can be written in the form of conservation law. However, as it is common in the field of PDEs and SPDEs, classical or strong solutions do not exist in general and, on the other hand, weak solutions are not unique. The notion of kinetic formulation and kinetic solution turns out to be a very convenient tool to overcome these difficulties. In this talk, I will present a well-posedness result for degenerate parabolic stochastic conservation laws and, in the case of hyperbolic stochastic conservation laws, discuss the hydrodynamic limit of an approximation in the sense of Bhatnagar-Gross-Krook.


01.10.12	Overview of Lectures of the Winter Term 2012/2013 In order to enable all students to choose the lectures of our institute which fits their interest all lecturers will give a short overview of their courses.

01.10.12

Overview of Lectures of the Winter Term 2012/2013

In order to enable all students to choose the lectures of our institute which fits their interest all lecturers will give a short overview of their courses.


29.10.10	Takashi Suzuki (Osaka University) : Simultaneous blowup and collapse mass separation in a competitive system of chemotaxis

29.10.10

Takashi Suzuki (Osaka University) : Simultaneous blowup and collapse mass separation in a competitive system of chemotaxis


13.03.03	Karsten Kruse (MPI PKS Dresden) : Dynamical and mechanical properties of the cytoskeleton
13.03.03	Lev Truskinovsky (Ecole Polytechnique) : Stability of skeletal muscles on a "descending limb"

13.03.03

Karsten Kruse (MPI PKS Dresden) : Dynamical and mechanical properties of the cytoskeleton

13.03.03

Lev Truskinovsky (Ecole Polytechnique) : Stability of skeletal muscles on a "descending limb"


04.02.02	Jürgen Jost (MPI MiS, Leipzig) : A brief introduction to supersymmetry

04.02.02

Jürgen Jost (MPI MiS, Leipzig) : A brief introduction to supersymmetry

Informal Seminar

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