4 papers · 1 filter
Möbius-Type Structures in Non-Orientable Singular Semi-Riemannian Manifolds
Nathalie E. Rieger
Our objective is to illuminate the global structure of non-orientable manifolds with signature-changing metrics, with particular emphasis on global topological obstructions. Using…
A Transformation Theorem for Transverse Signature-Type Changing Semi-Riemannian Manifolds
W. Hasse, N. E. Rieger
In the early eighties Hartle and Hawking put forth that signature-type change may be conceptually interesting, paving the way to the so-called 'no boundary' proposal for the initia…
Pseudo-timelike loops in signature changing semi-Riemannian manifolds with a transverse radical
N. E. Rieger, W. Hasse
In 1983, Hartle and Hawking proposed the no-boundary proposal, suggesting that the universe has no beginning in the sense of a spacetime singularity or boundary. Nevertheless, ther…
Embedding Signature-Changing Manifolds: A Braneworld and Kaluza-Klein Perspective
N. E. Rieger
We investigate a class of semi-Riemannian manifolds characterized by smooth metric signature changes with a transverse radical. This class includes spacetimes relevant to cosmologi…