Causality and Conjugate Points in General Plane Waves

J. L. Flores, M. Sánchez

Let $M=M_0\times {\mathbb{R}}^2$ be a pp--wave type spacetime endowed with the metric $<\cdot ,\cdot {>}_z=<\cdot ,\cdot {>}_x+2dudv+H(x,u)d{u}^2$, where $(M_0,<\cdot ,\cdot {>}_x)$ is any R…