Update README.md

Author: andrewrosemberg

README.md

@@ -35,9 +35,9 @@ This student-led course explores modern techniques for controlling — and learn
 | 8  | 10/10/2025   | **External seminar 2** TBD (speaker to be confirmed) | Topology **optimization** | |
 | 9  | 10/17/2025   | **External seminar 3 — François Pacaud** | GPU-accelerated optimal control | |
 |10  | 10/24/2025   | Lecture | Physics-Informed Neural Networks (PINNs): formulation & pitfalls | |
-|11  | 10/31/2025   | **External seminar 4** TBD (speaker to be confirmed) | Neural Differential Equations: PINNs + classical solvers | |
+|11  | 10/31/2025   | **External seminar 4** - Chris Rackauckas | Neural Differential Equations: PINNs + classical solvers | |
 |12  | 11/07/2025   | Lecture | Neural operators (FNO, Galerkin Transformer); large-scale surrogates | |
-|13  | 11/14/2025   | **External seminar 5** TBD (speaker to be confirmed) | Scalable PINNs / neural operators; CFD & weather applications | |
+|13  | 11/14/2025   | **External seminar 5** - Charlelie Laurent | Scalable PINNs / neural operators; CFD & weather applications | |
 |14  | 11/21/2025   | Lecture | Robust control & min-max DDP (incl. PDE cases); chance constraints; Data-driven control & RL-in-the-loop | |
 
 ## Reference Material