Almost global smooth solutions of the 3D quasilinear Klein-Gordon equations on the product space ${\mathbb{R}}^2\times \mathbb{T}$

Jun Li, Fei Tao, Huicheng Yin

In the paper, for the 3D quasilinear Klein-Gordon equation with the small initial data posed on the product space ${\mathbb{R}}^2\times \mathbb{T}$, we focus on the lower bound of…