Mass from an Extrinsic Point of View
Alexandre de Sousa, Frederico Girão
TL;DR
The paper develops an extrinsic perspective on the Gauss-Bonnet-Chern mass $m_q$ by introducing asymptotically Euclidean immersions and proving a version of the Hsiung-Minkowski identities for noncompact submanifolds. It then expresses $m_q$ as a linear combination of intrinsic curvature data, specifically $(n-2q)\int S_{2q}\,dM$ and $(2q+1)\int \langle S_{2q+1}, \bar{Z}\rangle \, dM$, via an explicit mass formula $m_q = a(n,q)[(n-2q)\int S_{2q} + (2q+1)\int \langle S_{2q+1}, \bar{Z}\rangle]$, under asymptotic and integrability assumptions. The authors connect this to the Lovelock tensor $G_{(q)}$ and Newton transformations, providing a flux-type expression and a gradient-field refinement, and derive a geometric inequality that must hold if the PMT for the GBC mass is valid. They also propose conjectures on asymptotically Euclidean immersions and their implications for the PMT, highlighting a path to deducing PMT results from intrinsic-extrinsic relations. Overall, the work links extrinsic geometric data to global mass-type invariants, offering a framework to study positivity and rigidity in higher-order curvature settings.
Abstract
We express the $q$-th Gauss-Bonnet-Chern mass of an immersed submanifold of Euclidean space as a linear combination of two terms: the total $(2q)$-th mean curvature and the integral, over the entire manifold, of the inner product between the $(2q+1)$-th mean curvature vector and the position vector of the immersion. As a consequence, we obtain, for each $q$, a geometric inequality that holds whenever the positive mass theorem (for the $q$-th Gauss-Bonnet-Chern mass) holds.
