Inner Lipschitz Geometry of Complex Surface Germs with Non-Isolated Singularities: A Complete Classification

Let $(X,0)$ be a germ of a reduced and irreducible complex surface embedded in $({\mathbb{C}}^k,0)$. In this paper, we give a complete invariant of the inner Lipschitz geometry of complex surface germs, extending the result of Birbrair–Neumann–Pichon \cite{BNP} to the non-isolated case. This invariant is expressed in terms of numerical invariants associated with the coordinate functions $f_1,\dots ,f_k$ of the normalization map $n:(\bar{X},0)\to (X,0)\subset ({\mathbb{C}}^k,0)$, together with the combinatorics of a suitable good resolution of $(\bar{X},0)$.