Cotygodniowe seminarium badawcze
2022-11-03, godz. 12:30, 5070
Samer Dweik (MIM UW)
On the regularity of the transport density in the import/export transport problem
The mass transport problem dates back to a work from 1781 by Gaspard Monge (Mémoire sur la théorie des déblais et des remblais) where he formulated a natural question in economics which deals with the optimal way of moving points from one mass distribution to another in some ...
2022-10-27, godz. 12:30, 5070
Prof. Igor Pazanin (Department of Mathematics, Faculty of Science, University of Zagreb, Croatia)
The effective boundary condition on a porous wall
The aim of this talk is to present the derivation of the new effective boundary condition for the fluid flow in a domain with porous boundary. Starting from the Stokes system in a domain with an array of small holes on the boundary and using the homogenization and the boundary layers, we...
2022-10-20, godz. 12:30, 5070
Remy Rodiac (Université Paris-Saclay)
On the convergence of critical points of the Ambrosio-Tortorelli functional
In order to describe the behavior of an elastic material undergoing fracture, we can use a variational model and the so-called Mumford-Shah energy defined on a subspace of SBV functions. One difficulty is that the critical points of this energy are difficult to approximate by numerical methods. One ...
2022-10-13, godz. 12:30, 5070
Mateusz Dembny (doktorant SDNŚiS)
On optimal Harnack bounds for a fractional heat equation
Considering the linear heat equation, the celebrated Li-Yau inequality states that for positive solutions we have $\Delta \log u \geq - \frac{n}{2t}$. By integrating this inequality along a straight space-time interval between two points, we may deduce the sharp Harnack estimate. In recent ye...
2022-10-06, godz. 12:30, 5070
Grzegorz Łukaszewicz (MIM UW)
The method of physical analogy
The talk follows my previous one entitled "An analogy between electromagnetism and hydrodynamics" and focuses on some basic features of analogies between mathematical models of physical phenomena, such as partial coincidences, uniqueness of correspondence, classification ...
2022-06-09, godz. 12:30, Zoom
Sadokat Malikova (SDNŚiP)
Approximation of rigid obstacle by highly viscous fluid
This talk is devoted to the problem concerning the approximation of a rigid obstacle for flows governed by the stationary Navier-Stokes equations in the two-dimensional case. The idea is to consider a highly viscous fluid in the place of the obstacle. Formally, as the fluid viscosit...
2022-06-02, godz. 12:30, Zoom
Maja Szlenk (SDNŚiS)
On the equations modelling certain non-Newtonian compressible fluids
The talk is devoted to the problem of existence of weak solutions to the compressible Stokes system with variable viscosity coefficients. Depending on the form of the stress tensor, different tools are required to deal with the obtained system. I will compare some types of equations modelling non-Ne...
2022-05-26, godz. 12:30, Zoom (see below)
Łukasz Chomienia (SDNŚiP UW)
Higher regularity of weak solutions on low-dimensional structures
The talk is devoted to a regularity of weak solutions of elliptic PDEs on irregular, lowdimensional subsets of the Euclidean space. Due to the singular nature of considered structures and technicalities related to functional spaces, it is not possible to apply standard regularity theorems in a st...
2022-05-05, godz. 12:30, Zoom (link below the abstract)
Arttu Karppinen (MIM UW )
Stability of solutions to elliptic PDEs under Musielak-Orlicz growth
We investigate stability of solutions to elliptic nonlinear partial differential equations -div(A_i(x,Du))=0 when the growth rate of the differential operator A_i varies. A model example would be to consider solutions of p_i-Laplace equations with p_i converging to some p. Our framework considers Mu...
2022-04-28, godz. 12:30, Zoom (szczegóły niżej)
John Shaw (Department of Geosciences, University of Arkansas)
Necessary conditions for the stability of simple loops
Many self-formed flow networks in nature are loopy, and these loops can occur because of adaptation to fluctuating hydrologic boundary conditions. However, the relationship between fluctuations and loop stability has not been thoroughly tested at the scale of a single loop. We use linear stabi...