Veranstaltungen

Mittwoch, 15.01.2025, 10:00 Uhr (WIAS-ESH)

Forschungsseminar Mathematische Statistik
Xiaorui Zuo, National University of Singapore , Singapur:
Cryptos have rough volatility and correlated jumps
mehr ... Veranstaltungsort
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Weitere Informationen
Dieser Vortrag findet hybrid statt. Die Teilnahme per Zoom ist über den (neuen!) Link: https://hu-berlin.zoom-x.de/j/62476510180?pwd=1bws9DORlDM2Iub3ANrb7zzDNANvsJ.1

Veranstalter
Humboldt-Universität zu Berlin
Universität Potsdam
WIAS Berlin

Mittwoch, 04.12.2024, 11:30 Uhr (WIAS-405-406)

Seminar Interacting Random Systems
Günter Last, Karlsruher Institut für Technologie:
tba
mehr ... Veranstaltungsort
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, 4. Etage, Raum: 405/406

Veranstalter
WIAS Berlin

Donnerstag, 28.11.2024, 14:00 Uhr (WIAS-HVP-3.13)

Seminar Numerische Mathematik
Dr. Lucas Omar Muller, University of Trento, Italien:
Towards real-life computional haemodynamics
mehr ... Veranstaltungsort
Weierstraß-Institut, Hausvogteiplatz 11A, 10117 Berlin, 3. Etage, Raum: 3.13

Abstrakt
Understanding the fundamental forces driving human physiology relies on a deep understanding of the circulation. During our daily life, the cardiovascular system is exposed to a wide range of biomechanical environments. This complexity requires a systemic approach to integrate phenomena across various temporal and spatial scales. Most of the research efforts in this do- main have focused on simplified cardiovascular scenarios such as the resting state, the supine position, and occasionally disease conditions. However, the cardiovascular system experiences large deviations from such prototypical conditions, which are, in many cases, highly beneficial to sustaining a healthy life. The impact of fundamental factors such as respiration, control mech- anisms, gravity, diverse physiological states (e.g., exercise or sleep conditions), and the integration of organ-specific physiology and disease into blood flow models has only been partially addressed. This talk aims to explore ongoing work in the field of computational hemodynamics at the systemic scale exploiting an anatomically detailed arterio-venous network 1D model [1] and highlighting modelling and numerical challenges related to simulations that intend to incorporate three aspects that are inextri- cably coupled to the circulation in our routine life: (i) the effect of respiration, (ii) the effect of orthostatic stress, and (iii) the presence of massive microvascular networks.

Weitere Informationen
Numerics Seminar

Veranstalter
WIAS Berlin

Mittwoch, 20.11.2024, 11:30 Uhr (WIAS-405-406)

Seminar Interacting Random Systems
Júlia Komjáthy, TU Delft:
tba
mehr ... Veranstaltungsort
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, 4. Etage, Raum: 405/406

Veranstalter
WIAS Berlin

Dienstag, 19.11.2024, 13:30 Uhr (WIAS-406)

Seminar Materialmodellierung
Angeliki Koutsimpela, Universität Augsburg:
Mean-field limits for interacting particle systems
mehr ... Veranstaltungsort
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, 4. Etage, Weierstraß-Hörsaal (Raum: 406)

Veranstalter
WIAS Berlin

Donnerstag, 14.11.2024, 10:00 Uhr (WIAS-Library)

Joint Research Seminar on Nonsmooth Variational Problems and Operator Equations / Mathematical Optimization
Dr. Amal Alphonse, WIAS Berlin:
Free boundary problems as limits of a bulk-surface model for receptor-ligand interactions on evolving domains
mehr ... Veranstaltungsort
Weierstraß-Institut, Hausvogteiplatz 5-7, 10117 Berlin, R411

Abstrakt
We derive various free boundary problems as reaction or singular limits of a coupled bulk-surface reaction-diffusion system on an evolving domain. These limiting free boundary problems may be formulated as Stefan-type problems on an evolving hypersurface. These results, which are new even in the setting where there is no domain evolution, are of particular relevance to an application in cell biology. In this talk, I will discuss the modelling, sketch the analysis, show some numerical simulations and finish with some open questions. Based on a joint work with Charlie Elliott, Chandrasekhar Venkataraman and Diogo Caetano.

Weitere Informationen
Joint Research Seminar on Nonsmooth Variational Problems and Operator Equations

Veranstalter
WIAS Berlin

Mittwoch, 13.11.2024, 15:15 Uhr (WIAS-405-406)

Berliner Oberseminar „Nichtlineare partielle Differentialgleichungen” (Langenbach-Seminar)
Lukas Abel, Humboldt-Universität zu Berlin:
A scaling law for a model of epitaxial growth with dislocations
mehr ... Veranstaltungsort
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, 4. Etage, Raum: 405/406

Abstrakt
Epitaxy is a special form of crystal growth and of great importance in modern technology. We consider a crystalline film on a (rigid) substrate. The misfit between the crystal structures of the film and the substrate can lead to dislocations and can have an influence on the morphology of the film. Dislocations are topological defects of the crystallographic lattice. In this talk we will study a variational model from the literature. It is based on linearized elasticity and additionally takes into account the surface energy of the film's free surface as well as the dislocation nucleation energy. In particular we will discuss a new scaling law for the infimum of the energy. This includes a new construction for the upper bound and a new variant of a ball-construction combined with thorough local estimates for the lower bound. The results indicate that in certain parameter regimes, the formation of dislocations is expected. Reference: Preprint arXiv no. 2403.13646, https://arxiv.org/abs/2403.13646

Weitere Informationen
Oberseminar “Nichtlineare Partielle Differentialgleichungen” (Langenbach Seminar)

Veranstalter
Humboldt-Universität zu Berlin
WIAS Berlin

13. November 2024 (Erwin-Schroedinger-Zentrum)

Workshop/Konferenz: Foundations of Modern Nonparametric Statistics
mehr ... Veranstaltungsort
Erwin-Schrödinger Zentrum Adlershof , Rudower Chaussee 26, 12489 Berlin.

Veranstalter
Humboldt-Universität zu Berlin
Universität Potsdam
WIAS Berlin

Donnerstag, 07.11.2024, 15:00 Uhr (WIAS-405-406)

Seminar Materialmodellierung
Dr. Tomáš Bodnár, Czech Technical University in Prague, Tschechische Republik:
On the use of viscoelastic fluids flows models in hemolysis prediction
mehr ... Veranstaltungsort
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, 4. Etage, Raum: 405/406

Abstrakt
The mathematical modeling and numerical simulations of blood flows is a very challenging problem due to complex rheological properties of blood. The blood can be considered as a suspension of red blood cells in blood plasma, resulting in a shear-thinning and viscoelastic behavior of the whole blood. It is well known that high levels of stress in blood flows, typically found in ventricular assist devices for example, can lead to blood damage - the hemolysis. Under high stress the red blood cells can be damaged or ruptured, which can lead to serious medical consequences. This is why a considerable effort has been dedicated by numerous researchers to prediction of the blood damage, based on the detailed knowledge of the flow field. There exists a number of models for hemolysis, but non of them is generally accepted as a definitive, convenient and reliable tool for prediction of hemolysis. The aim of the presented talk is to point out the importance of inclusion of non-Newtonian rheology of blood in the hemolysis predictions. The similarity between some of the promising stretch based tensorial models of hemolysis and the non-linear viscoelastic rheology models offers the possibility to estimate the hemolysis directly from the local stretch tensor. This possibility will be presented and discussed in detail.

Weitere Informationen
Seminar Materialmodellierung

Veranstalter
WIAS Berlin

Mittwoch, 06.11.2024, 11:30 Uhr (WIAS-405-406)

Seminar Interacting Random Systems
Jonas Köppl, WIAS Berlin:
Spontaneous time-symmetry breaking in interacting particle systems
mehr ... Veranstaltungsort
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, 4. Etage, Raum: 405/406

Abstrakt
We study the behaviour of interacting particle systems on the integer lattice $mathbbZ^d$ with a focus on symmetries of their stationary measures. In particular, we are interested in spontaneous symmetry breaking, i.e., situations where there are stationary measures that satisfy less symmetries than the transition rates themselves. Classical examples include the Glauber dynamics for the Ising model, where the global spin-flip symmetry is broken in dimensions $dgeq 2$ and the translation-symmetry is broken in dimension $dgeq3$. In this talk, we discuss the possibility of a spontaneous breaking of the time-symmetry, i.e., whether an interacting particle system with time-homogeneous rates can admit time-periodic behaviour. While this can easily be ruled out in finite volume, the situation is much more delicate in the thermodynamic limit. We provide a no-go theorem under the additional assumption of reversibility and exhibit examples of non-degenerate interacting particle systems which do indeed exhibit spontaneous time-symmetry breaking.

Veranstalter
WIAS Berlin