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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The geometry of black hole spacetimes can be probed with exquisite precisionin the gravitational-wave window, and possibly also in the optical regime. Westudy the accretion of bright spots -- objects which emit strongly in theoptical or in gravitational waves -- by non-spinning black holes. The emissionas the object falls down the hole is dominated by photons or gravitons orbitingthe light ring, causing the total luminosity to decrease exponentially as${\cal L}_o\sim e^{-t/(3\sqrt{3}\,M)}$. Late-time radiation is blueshifted, dueto its having been emitted during the infall, trapped at the light ring andsubsequently re-emitted. These universal properties are a clear signature ofthe existence of light rings in the spacetime, and not particularly sensitiveto near horizon details.

The light ring and the appearance of matter accreted by black holes