Timeline for Is every strongly causal spacetime purely electric?
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
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| Jan 21 at 6:56 | history | edited | Daniele Tampieri | CC BY-SA 4.0 |
Minor formatting
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| Jan 12 at 16:41 | comment | added | Igor Khavkine | @BastamTajik The condition on the Weyl tensor is homogeneous in $u$, so it is equivalent to state it for all timelike $u$ (or causal $u$ in the weaker version). In turn, it is equivalent to state the weaker condition for only those causal $u$ that have $\|u\|=1$ w.r.t some Riemannian metric, which is now conveniently a compact set. You'll find that the choice of the Riemannian metric can be arbitrary, only the compactness of its unit sphere is used (so that its intersection with the closed light cone is also compact). | |
| Jan 12 at 16:26 | comment | added | Bastam Tajik | It's generally acceptable. But I cannot understand the passage that tries to prove that the non-vanishing subset is open. Specially where you choose an auxiliary Riemannian metric. Shouldn't it be a Lorenzian metric? Since the set of $u^a$ for which the norm is unit, is gonna be quite different. | |
| Jan 12 at 15:23 | vote | accept | Bastam Tajik | ||
| Jan 12 at 11:24 | history | answered | Igor Khavkine | CC BY-SA 4.0 |