Spatial degeneracy along weak geodesics in the space of Kähler potentials
Abstract
We study spatial Hessian degeneracy along weak Kähler geodesics. We construct examples in three settings: (1) On every compact Kähler manifold, the spatial form degenerates on a nonempty open set during an interior time interval, although both endpoints are smooth and strictly Kähler. (2) On ALE Kähler manifolds with a holomorphic quotient end and a decaying potential to the Euclidean metric, spatial degeneracy occurs on open regions arbitrarily far along an unbounded horn. (3) For cone and Poincaré endpoint metrics along a smooth divisor, normal spatial degeneracy occurs on open sets approaching the divisor. Both cone endpoints retain the prescribed angle. The first construction answers negatively the spatial-positivity question recorded in Darvas's survey. The ALE and divisor constructions show that weak geodesics need not preserve the asymptotic behavior of the endpoint metrics.
Related
- Branched Covers and Fiberwise Degeneration along Weak Kähler Geodesics
- Quasi-convexity of energy functions along Teichmüller geodesics
- Functional inequalities along Wasserstein geodesics
- Sharp Poincaré interpolation along Wasserstein geodesics
- Canonical Bochner-Kähler potentials via the Sasaki-Kähler correspondence
BibTeX
@misc{xiao2026spatial,
title = {{Spatial degeneracy along weak geodesics in the space of Kähler potentials}},
author = {Xia Xiao and Qi Yao},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.00744},
eprint = {2611.00744},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.00744},
}
RIS
TY - UNPB
TI - Spatial degeneracy along weak geodesics in the space of Kähler potentials
AU - Xia Xiao
AU - Qi Yao
PY - 2026
DA - 2026/11/01
PB - arXiv
DO - 10.48550/arxiv.2611.00744
UR - https://arxiv.org/abs/2611.00744
AB - We study spatial Hessian degeneracy along weak Kähler geodesics. We construct examples in three settings: (1) On every compact Kähler manifold, the spatial form degenerates on a nonempty open set during an interior time interval, although both endpoints are smooth and strictly Kähler. (2) On ALE Kähler manifolds with a holomorphic quotient end and a decaying potential to the Euclidean metric, spatial degeneracy occurs on open regions arbitrarily far along an unbounded horn. (3) For cone and Poincaré endpoint metrics along a smooth divisor, normal spatial degeneracy occurs on open sets approaching the divisor. Both cone endpoints retain the prescribed angle. The first construction answers negatively the spatial-positivity question recorded in Darvas's survey. The ALE and divisor constructions show that weak geodesics need not preserve the asymptotic behavior of the endpoint metrics.
ER -