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arXiv · 1404.1845

Karlhede's invariant and the black hole firewall proposal

J. W. Moffat·V. T. Toth
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Abstract

The Karlhede invariant is formed from the contraction of the covariant derivative of the Riemann tensor. It is a coordinate invariant that vanishes at the Schwarzschild event horizon $r=2m$. The vanishing of the invariant allows an observer to construct a local measuring device and use it to detect an event horizon while falling into a black hole. Recent proposals postulate the existence of a "firewall" at the event horizon that may incinerate an infalling observer. These proposals face an apparent paradox if a freely falling observer detects nothing special in the vicinity of the horizon. The behavior of Karlhede's invariant raises the possibility that the event horizon is a real physical membrane with measurable properties that are detectable by a freely falling observer.

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J. W. Moffat, V. T. Toth. 2014-04-08. Karlhede's invariant and the black hole firewall proposal. https://arxiv.org/abs/1404.1845

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