Characterization of Gromov-type geodesics
F MÊmoli, Z Wan - arXiv preprint arXiv:2105.05369, 2021 - arxiv.org
F MÊmoli, Z Wan
arXiv preprint arXiv:2105.05369, 2021•arxiv.orgThe collection $\mathcal {M} $ of all isometry classes of compact metric spaces endowed
with the Gromov-Hausdorff distance $ d_\mathcal {GH} $ is known to be a geodesic space.
However, there is no known structural characterization of geodesics in $\mathcal {M} $. In
this paper we provide two such characterizations. We first prove that every Gromov-
Hausdorff geodesic is in fact a geodesic in the Hausdorff hyperspace of some compact
metric space, which we call a Hausdorff geodesic. Inspired by this characterization, we …
with the Gromov-Hausdorff distance $ d_\mathcal {GH} $ is known to be a geodesic space.
However, there is no known structural characterization of geodesics in $\mathcal {M} $. In
this paper we provide two such characterizations. We first prove that every Gromov-
Hausdorff geodesic is in fact a geodesic in the Hausdorff hyperspace of some compact
metric space, which we call a Hausdorff geodesic. Inspired by this characterization, we …
The collection of all isometry classes of compact metric spaces endowed with the Gromov-Hausdorff distance is known to be a geodesic space. However, there is no known structural characterization of geodesics in . In this paper we provide two such characterizations. We first prove that every Gromov-Hausdorff geodesic is in fact a geodesic in the Hausdorff hyperspace of some compact metric space, which we call a Hausdorff geodesic. Inspired by this characterization, we further elucidate a structural connection between Hausdorff geodesics and Wasserstein geodesics: every Hausdorff geodesic is equivalent to a so-called Hausdorff displacement interpolation. This equivalence allows us to establish that every Gromov-Hausdorff geodesic is dynamic, a notion which we develop in analogy with dynamic optimal couplings in the theory of optimal transport. Besides geodesics in , we also study geodesics on the collection of isomorphism classes of compact metric measure spaces. Sturm constructed a family of Gromov-type distances on , which we denote (for ), and proved that is also a geodesic space. We are interested in geodesics which are (essentially) Wasserstein geodesics. We prove the set of such geodesics is dense in the set of all geodesics and identify a rich class of such geodesics.
arxiv.org