English

Entropy and stability of hyperbolic manifolds

Differential Geometry 2025-08-29 v5

Abstract

Let (M,g0)(M,g_0) be a closed oriented hyperbolic manifold of dimension at least 33. By the volume entropy inequality of G. Besson, G. Courtois and S. Gallot, for any Riemannian metric gg on MM with same volume as g0g_0, its volume entropy h(g)h(g) satisfies h(g)n1h(g)\geq n-1 with equality only when gg is isometric to g0g_0. We show that the hyperbolic metric g0g_0 is stable in the following sense: if gig_i is a sequence of Riemaniann metrics on MM of same volume as g0g_0 and if h(gi)h(g_i) converges to n1n-1, then there are smooth subsets ZiMZ_i\subset M such that both Vol(Zi,gi)\mathrm{Vol}(Z_i,g_i) and Area(Zi,gi)\mathrm{Area}(\partial Z_i,g_i) tend to 00, and (MZi,gi)(M\setminus Z_i,g_i) converges to (M,g0)(M,g_0) in the measured Gromov-Hausdorff topology. The proof relies on showing that any spherical Plateau solution for MM is intrinsically isomorphic to (M,(n1)24ng0)(M,\frac{(n-1)^2}{4n} g_0).

Keywords

Cite

@article{arxiv.2302.07422,
  title  = {Entropy and stability of hyperbolic manifolds},
  author = {Antoine Song},
  journal= {arXiv preprint arXiv:2302.07422},
  year   = {2025}
}

Comments

arXiv admin note: text overlap with arXiv:2202.10636 v2: minor corrections. v3: main theorem corrected, examples added in Subsection 3.4. v4: stability in the Gromov-Prokhorov topology is stated as an open question, Subsection 3.4 is removed after discussions with Dongming (Merrick) Hua, Remark 3.9 introduces a notion of intermediate areas for manifolds. v5 To appear in GAFA