Global solutions to quasilinear wave-Klein-Gordon systems in two space dimensions

In this paper we prove global existence and global behavior of solutions to quasilinear wave-Klein-Gordon systems in ${\mathbb{R}}^{1+2}$ with quadratic nonlinearities satisfying the null condition. We consider small, regular and compactly supported initial data, and prove global existence, pointwise decay estimates and linear scattering for the solutions.