On the Gross-Keating invariant of a quadratic form over a non-archimedean local field

Let $B$ be a half-integral symmetric matrix of size $n$ defined over ${\mathbb{Q}}_p$. The Gross-Keating invariant of $B$ was defined by Gross and Keating, and has important applications to arithmetic geometry. But the nature of the Gross-Keating invariant was not understood very well for $n\ge 4$. In this paper, we establish basic properties of the Gross-Keating invariant of a half-integral symmetric matrix of general size over an arbitrary non-archimedean local field of characteristic zero.