# Cubic NLW/NLKG on R2

• LWP for $s \geq 1/4$ by Strichartz estimates (see e.g. LbSo1995)
• GWP for $s \geq 1/2$ for defocussing NLKG Bo1999 and for defocussing NLW Fo-p
• For $s \geq 1$ this is clear from energy conservation (for both NLKG and NLW).