Upcoming Events
- Wednesday, 08.05.2024, 17:15 (WIAS-ESH)
- Berliner Kolloquium Wahrscheinlichkeitstheorie
Hendrik Weber:
A priori bounds for the nonlinear Parabolic Anderson Model
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Host
Humboldt-Universität zu Berlin
Technische Universität Berlin
WIAS Berlin
- Wednesday, 08.05.2024, 16:15 (WIAS-ESH)
- Berliner Kolloquium Wahrscheinlichkeitstheorie
Máté Gerencsér, TU Vienna:
Regularisation by rough multiplicative noise
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Abstract
Differential equations driven by multiplicative fractional Brownian motions are considered. We will focus on the regime 1/3 < H < 1/2, where on one hand the irregularity of the noise requires rough path theory to interpret the equation, on the other hand the regularisation effects are stronger than Brownian and one even expects that distributional drifts to be admissible. We discuss how these positive and negative sides of the noise can be reconciled. Based on joint works with K. Dareiotis and C. Ling
Host
Humboldt-Universität zu Berlin
Technische Universität Berlin
WIAS Berlin
- Wednesday, 08.05.2024, 14:15 (WIAS-ESH)
- Berliner Oberseminar „Nichtlineare partielle Differentialgleichungen” (Langenbach-Seminar)
Prof. Dr. Markus Schmidtchen, Technische Universität Dresden:
Gradient flow solutions for porous medium equations with nonlocal Lévy-type pressure
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Abstract
We study a porous medium-type equation whose pressure is given by a nonlocal Lévy-operator associated to a symmetric jump Lévy kernel. The class of nonlocal operators under consideration appears as a generalisation of the classical fractional Laplace operator. For the a class of Lévy-operators, we construct weak solutions using minimising movements. (Joint work with G. Foghem and D. Padilla.)
Host
Humboldt-Universität zu Berlin
WIAS Berlin
- Wednesday, 08.05.2024, 11:30 (WIAS-405-406)
- Seminar Interacting Random Systems
Tejas Iyer, WIAS Berlin:
Persistent hubs in generalised preferential attachment trees and certain branching processes
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, 4. Etage, Raum: 405/406
Abstract
In a tree growing in discrete time-steps, a node is called a persistent hub if it becomes, and remains, the fixed node of maximal degree during the evolution of the process. For a large class of generalised preferential attachment trees, we provide necessary and sufficient criteria for the emergence of a persistent hub, building on previous work by Dereich and Mörters; Galashin, and Banerjee and Bhamidi. During the talk, we will explore part of the proof, delving into the connection with continuous time branching processes.
Further Informations
Seminar Interacting Random Systems (Hybrid Event)
Host
WIAS Berlin
- Tuesday, 07.05.2024, 14:30 (WIAS-Library)
- Joint Research Seminar on Nonsmooth Variational Problems and Operator Equations / Mathematical Optimization
Martin Brokate, Technische Universität München:
Rate independent evolutions: some basics, some progress
more ... Location
Weierstraß-Institut, Hausvogteiplatz 5-7, 10117 Berlin, R411
Abstract
We discuss some elementary rate independent evolutions, in particular the stop and the play, and offer remarks on the historical development. We also elaborate on issues concerning related optimal control problems.
Further Informations
Joint Research Seminar on Nonsmooth Variational Problems and Operator Equations
Host
WIAS Berlin
- Tuesday, 07.05.2024, 14:00 (WIAS-ESH)
- Seminar Numerische Mathematik
Timo Streckenbach:
Alternative approach to model lattice mismatch of semiconductor nanostructures
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Abstract
About using MFC (multi freedom constraints) to connect nanostructures with different lattice constants in FEM strain simulation.
Host
WIAS Berlin
- Tuesday, 07.05.2024, 13:30 (WIAS-ESH)
- Seminar Numerische Mathematik
Dr. Dilara Abdel:
Modeling and simulation of vacancy-assisted charge transport in innovative semiconductor devices
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Abstract
In response to the climate crisis, there is a need for technological innovations to reduce the escalating CO$_2$ emissions. Two promising semiconductor technologies in this regard, perovskite-based solar cells and memristive devices based on two-dimensional layered transition metal dichalcogenide (TMDC), can potentially contribute to the expansion of renewable energy sources and the development of energy-efficient computing hardware. Within perovskite and TMDC materials, ions dislocate from their ideal position in the semiconductor crystal and leave void spaces. So far, the precise influence of these vacancies and their dynamics on device performance remain underexplored.
Therefore, this talk is dedicated to comprehensively examining the impact of vacancy-assisted charge transport in innovative semiconductor devices through a theoretical approach by modeling and simulating systems of partial differential equations. We start by deriving drift-diffusion equations using thermodynamic principles. Furthermore, we formulate drift-diffusion models to describe charge transport in perovskite solar cells and TMDC memristors. We discretize the transport equations via the finite volume method and establish the existence of discrete solutions. Our study concludes with simulations conducted with an open source software tool developed in the programming language Julia. These simulations explore the influence of volume exclusion effects on charge transport in perovskite solar cells and compare our simulation results with experimental measurements found in literature for TMDC-based memristive devices.
Host
WIAS Berlin
