English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The ingoing Vaidya metric is introduced as a model for a non-rotatinguncharged black hole emitting Hawking radiation. This metric is expected tocapture the physics of the spacetime for radial coordinates up to a smallmultiple $(>1)$ of the Schwarzschild radius. For larger radii, it will give anexcellent approximation to the spacetime geometry in the case of astrophysicalblack holes $(M\ge M_{\astrosun})$, except at extremely large distances fromthe horizon (exceeding the cosmic particle horizon). In the classroom, themodel may serve as a first exploration of non-stationary gravitational fields.Several interesting predictions are developed. First, particles dropped earlyenough before complete evaporation of the black hole cross its horizon aseasily as with an eternal black hole. Second, the Schwarzschild radius takes onthe properties of an apparent horizon, and the true event horizon of the blackhole is \emph{inside} of it, because light can escape from the shrinkingapparent horizon. Third, a particle released from rest close enough to theapparent horizon is strongly repelled and may escape to infinity. Aninterpretation is given, demonstrating that such a particle would be able tocompete, for a short time, in a race with a photon.

The Vaidya metric: expected and unexpected traits of evaporating black holes