# Are Causality Violations Undesirable?

@article{Monroe2008AreCV, title={Are Causality Violations Undesirable?}, author={Hunter Monroe}, journal={Foundations of Physics}, year={2008}, volume={38}, pages={1065-1069} }

Causality violations are typically seen as unrealistic and undesirable features of a physical model. The following points out three reasons why causality violations, which Bonnor and Steadman identified even in solutions to the Einstein equation referring to ordinary laboratory situations, are not necessarily undesirable. First, a space-time in which every causal curve can be extended into a closed causal curve is singularity free—a necessary property of a globally applicable physical theory…

## 5 Citations

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## References

SHOWING 1-10 OF 22 REFERENCES

COMMENTS, REPLIES AND NOTES: Globally hyperbolic spacetimes can be defined as 'causal' instead of 'strongly causal'

- Philosophy, Mathematics
- 2006

The classical definition of {\em global hyperbolicity} for a spacetime $(M,g)$ comprises two conditions: (A) compactness of the diamonds $J^+(p)\cap J^-(q)$, and (B) strong causality. Here we show…

Topology change in classical general relativity

- Mathematics, Physics
- 1994

This paper clarifies some aspects of Lorentzian topology change, and it extends to a wider class of spacetimes previous results of Geroch and Tipler that show that topology change is only to be had…

The end of the time machine

- Philosophy
- 2001

It is proved that any extendible spacetime U has a maximal extension containing no closed causal curves outside the chronological past of U, and it is interpreted as impossibility (in classical general relativity) of the time machines.

The Large Scale Structure of Space-Time

- Physics
- 1973

The theory of the causal structure of a general space-time is developed, and is used to study black holes and to prove a number of theorems establishing the inevitability of singualarities under certain conditions.

No time machines in classical general relativity

- Philosophy
- 2002

Irrespective of local conditions imposed on the metric, any extendible spacetime U has a maximal extension containing no closed causal curves outside the chronological past of U. We prove this fact…

Topological censorship.

- PhysicsPhysical review letters
- 1993

It is shown that the topology of physically reasonable isolated systems is shrouded from distant observers, or in other words there is a topological censorship principle.

CLOSED TIMELIKE CURVES IN CLASSICAL RELATIVITY

- Physics
- 2002

Spacetimes of general relativity containing closed timelike curves (CTC) are usually dismissed as non-physical. However, it is now known that CTC may appear in spacetimes modelling simple laboratory…

Exact solutions of the Einstein-Maxwell equations with closed timelike curves

- Physics
- 2005

We examine two electrovac spacetimes, the Kerr-Newman solution and another due to Perjes, which represent single charged, rotating, magnetic objects. Both contain regions with closed timelike curves…