NLS approximation for a scalar FPUT system on a 2D square lattice with a cubic nonlinearity

Ioannis Giannoulis, Bernd Schmidt, Guido Schneider

We consider a scalar Fermi-Pasta-Ulam-Tsingou (FPUT) system on a square 2D lattice with a cubic nonlinearity. For such systems the NLS equation can be derived to describe the evolu…