Seminar: Gradient flows as PDEs (WS12/13)

Time: Wednesday 14-16
Room: Endenicher Allee 60, 2.040

Description
Topics

Schedule and Topics

10.10.12 André

• Gradientflows in $\mathbb{R}^n$ : Characterization of stationary points, linearization around critical points, convergence by convexity, implicit Euler time-discrete scheme and variational formulation
• Basic Riemannian Geometry: differentiation on manifolds
• First part of Otto theorem: convergence of (finite-dimensional) gradient flows of convex energies to stationary points on a Riemannian manifold

17.10.12 André

• Some more Riemannian Geometry: Riemannian connection/fundamental theorem of Riemannian geometry, geodesics, length/energy of curves, geodesics as energy minimizers, formula for Hessian
• Introduction to Fokker Planck equation: characterization of equilibrium solution, example Ornstein-Uhlenbeck process, behaviour in non-convex potential

24.10.12 Leonardo

• Classic results porous medium equation: Self-similar solutions by rescaling, stationary solutions
• Two gradient flow formulations for porous medium equation: $$L^2$$ and entropic gradient flow

31.10.12 Simon

• Wasserstein metric
• Time discrete variational formulation of Fokker Planck equation
• Existence of time-discrete solutions: Remarks on weak L¹-convergence** **

07.11.12 Angelo

• Physical derivation of PME: characterzation of unique minimizer and derivation of gradient functional (Darcy’s law, osmotic pressure)
• Asymptotic formulation: energy functional in rescaled equation
• Energy-entropy estimate: characterzation of unique minimizer and derivation of gradient functional
• Convergence in induced distance

12.11.12 (8:30) Stefan

• Construction of isometric submersion of flat manifold of diffeomorphisms on $\mathbb{R}^n$ onto manifold of densities $\mathcal{M}$
• Pullback of curves and geodesics under the submersion

28.11.12 Simon

• Convergence of time-discrete scheme to Fokker-Planck equation

26.11.12 (16:00) Leonardo

• Some results from Optimal Transport: Gradient and Hessian of convex functions via Alexandrov’s Theorem
• Identification of Wasserstein distance as induced distance
• Computation of the Hessians: displacement convexity and lower bounds

05.12.12 Dies Academicus

12.12.12. Angelo

• Towards rigorous results: smooth setting

19.12.12 Stefan

• Porous medium equation on manifolds
• Contraction in Wasserstein space by Eulerian calculus

09.01.13 Simon

• A non-local non-linear Fokker-Planck equation
• Example of Dynamic in special regimes
• setting of a constraint gradient flow

14.01.13 (16:00) Stefan

• Incompressible Euler equation and Arnolds interpretation
• Breniers relaxation and relation to Wasserstein distance

 16.01.13 Angelo

• Slow motions of gradient flows: Allen-Cahn equation

21.01.13 (16:00) Leonardo

• Rate of convergence for Fokker-Planck equation via transport inequalities (logarithmic Sobolev inequality, HWI-inequality)