Finslerian lightconvex boundaries: applications to causal simplicity and the space of cone geodesics $\mathcal{N}$

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Herrera, Jónatan, Sánchez, Miguel
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911255118217216
author Herrera, Jónatan
Sánchez, Miguel
author_facet Herrera, Jónatan
Sánchez, Miguel
contents Our outcome is structured in the following sequence: (1) a general result for indefinite Finslerian manifolds with boundary $(M,L)$ showing the equivalence between local and infinitesimal (time, light or space) convexities for the boundary $\partial M$, (2) for any cone structure $(M,\mathcal{C})$ which is globally hyperbolic with timelike boundary, the equivalence among: (a) the boundary $\partial M$ is lightconvex, (b) the interior $\mathring{M}$ is causally simple and (c) the space of the cone (null) geodesics $\mathcal{N}$ of $(\mathring{M},\mathcal{C})$ is Hausdorff, (3) in this case, the manifold structure of $\mathcal{N}$ is obtained explicitly in terms of elements in $\partial M$ and a smooth Cauchy hypersurface $S$, (4) the known results and examples about Hausdorfness of $\mathcal{N}$ are revisited and extended, leading to the notion of {\em causally simple spacetime with $T_2$-lightspace} as a step in the causal ladder below global hyperbolicity. The results are significant for relativistic (Lorentz) spacetimes and the writing allows one either to be introduced in Finslerian technicalities or to skip them. In particular, asymptotically AdS spacetimes become examples where the $C^{1,1}$ conformal extensions at infinity yield totally lightgeodesic boundaries, and all the results above apply.
format Preprint
id arxiv_https___arxiv_org_abs_2506_09032
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Finslerian lightconvex boundaries: applications to causal simplicity and the space of cone geodesics $\mathcal{N}$
Herrera, Jónatan
Sánchez, Miguel
Differential Geometry
General Relativity and Quantum Cosmology
53C60, 53C50, 53C22
Our outcome is structured in the following sequence: (1) a general result for indefinite Finslerian manifolds with boundary $(M,L)$ showing the equivalence between local and infinitesimal (time, light or space) convexities for the boundary $\partial M$, (2) for any cone structure $(M,\mathcal{C})$ which is globally hyperbolic with timelike boundary, the equivalence among: (a) the boundary $\partial M$ is lightconvex, (b) the interior $\mathring{M}$ is causally simple and (c) the space of the cone (null) geodesics $\mathcal{N}$ of $(\mathring{M},\mathcal{C})$ is Hausdorff, (3) in this case, the manifold structure of $\mathcal{N}$ is obtained explicitly in terms of elements in $\partial M$ and a smooth Cauchy hypersurface $S$, (4) the known results and examples about Hausdorfness of $\mathcal{N}$ are revisited and extended, leading to the notion of {\em causally simple spacetime with $T_2$-lightspace} as a step in the causal ladder below global hyperbolicity. The results are significant for relativistic (Lorentz) spacetimes and the writing allows one either to be introduced in Finslerian technicalities or to skip them. In particular, asymptotically AdS spacetimes become examples where the $C^{1,1}$ conformal extensions at infinity yield totally lightgeodesic boundaries, and all the results above apply.
title Finslerian lightconvex boundaries: applications to causal simplicity and the space of cone geodesics $\mathcal{N}$
topic Differential Geometry
General Relativity and Quantum Cosmology
53C60, 53C50, 53C22
url https://arxiv.org/abs/2506.09032