Semiclassical derivation of the Vlasov–Maxwell equation
Establish the rigorous semiclassical limit from the non-relativistic Maxwell–Schrödinger equation to the non-relativistic Vlasov–Maxwell equation as Planck’s constant tends to zero, without restricting to the monokinetic Euler–Maxwell case or introducing a regularization.
References
The rigorous derivation leading from Maxwell Schrodinger eq to Vlasov Maxwell in the limit as $\hbar \rightarrow 0$ is well recognized as an outstanding open problem.
— From the Maxwell-Schrödinger equation to the Euler-Maxwell equation in the semiclassical limit
(2610.11199 - Porat, 8 Oct 2026) in Section 1, “Background”