Causal monotonicity, omniscient foliations and the shape of space

Abstract

What is the shape of space in a spacetime? One way of addressing this issue is to consider edgeless spacelike submanifolds of the spacetime. An alternative is to foliate the spacetime by timelike curves and consider the quotient obtained by identifying points on the same timelike curve. In this article we investigate each of these notions and obtain conditions such that it yields a meaningful shape of space. We also consider the relationship between these two notions and find conditions for the quotient space to be diffeomorphic to any edgeless spacelike hypersurface. In particular, we find conditions in which merely local behavior (being spacelike) combined with the correct behavior on the homotopy level guarantees that a putative shape of space really is precisely that.

19 pages, AMSTeX

References in corpus (1)

• Ricci Fall-off in Static, Globally Hyperbolic, Non-singular Spacetimes

Cited by in corpus (6)

• Causal structures and causal boundaries
• General study and basic properties of causal symmetries
• Further properties of causal relationship: causal structure stability, new criteria for isocausality and counterexamples
• Causal symmetries
• Omniscient foliations and the geometry of cosmological spacetimes
• Remarks on causal decrease, omniscient foliations and null lines in spacetimes