Real-Time Dynamics at Large $N$

The large-$N$ limit of $O(N)$-symmetric bosonic field theories, or $U(N)$-symmetric fermionic field theories, is amenable to a saddle point approximation. As a result, there is a family of closely related algorithms for efficient lattice simulations in this limit, even in the presence of fermionic or real-time sign problems. These can be used to study quenches, or other observables for which