Magnitude of metric measure spaces and integrals over geodesics
Differential Geometry
2026-05-25 v1 Metric Geometry
Abstract
We propose a definition of magnitude for a length space with a Borel measure, which involves integrals over the set of geodesics. This quantity agrees with the magnitude of finite metric spaces, up to re-scaling the metric to ensure the convergence, when we use the counting measure on them. We also prove a version of the homogeneous magnitude theorem, by showing that the new definition agrees with the volume when we use the weight measure on a compact homogeneous Riemannian manifold. We compute various examples, which suggest that this quantity can capture information of non-uniqueness of geodesics, such as the injectivity radius, corresponding to the generating degrees of the magnitude homology.
Keywords
Cite
@article{arxiv.2605.23485,
title = {Magnitude of metric measure spaces and integrals over geodesics},
author = {Yoshinori Hashimoto},
journal= {arXiv preprint arXiv:2605.23485},
year = {2026}
}
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43 pages