Q-Math Seminar
A. Ibort (UC3M-ICMAT)
Random perturbations of flows and solutions of the Navier-Stokes equation
Thursday the 8th of October, 2026, 14:00, Room 2.2.D08
We show that solutions of the Navier-Stokes equation for an incompressible fluid can be obtained by averaging stochastic perturbations of solutions of Euler's equation. The average of a Brownian perturbation of a steady solution of the Euler equation defines, for small time, a time-dependent diffeomorphism whose generating vector field satisfies a generalized Navier-Stokes equation. The deviation of this generalized equation from the standard Navier-Stokes equation is controlled by a viscous residual whose leading term involves a transport--diffusion term. We identify a natural class of steady, parallel Euler flows for which this residual vanishes and the perturbed flow satisfies the exact Navier-Stokes equation. These results are placed in the context of recent developments including the stochastic Lagrangian representation of Constantin-Iyer, the SALT formulation of Holm, and regularization-by-noise results of Flandoli and collaborators.Link for online session: http://meet.google.com/vpk-ijfj-nov
F. Lledó (UC3M-ICMAT)
Superselection theory of the Quantum Double with boundaries
Thursday the 1st of October, 2026, 14:00, Room 2.2.D08
In this talk I will present the superselection structure of the quantum double model (a natural generalization of Kitaev's celebrated toric code) on the lattice $Z^2$. I will also show how boundaries modify this structure (based on some ongoing work with Joan Claramunt (UPC) and Laura Sáenz (UC3M-ICMAT)).