Planes in quadratic 4-space and associated shapes of lattices

Menny Aka, Konstantin Andritsch, Andreas Wieser

Let $Q=-x_1^2-x_2^2-x_3^2+x_4^2$ be the standard signature $(1,3)$ quadratic form. To each non-degenerate rational plane $L$ in the four-dimensional quadratic space $(\mathbb{Q}^4,…