# Quantum Black Holes in the Sky?

Quantum Black Holes in the Sky?

## A model-independent search for gravitational-wave echoes

Wednesday Nov 08, 2017
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Exotic compact objects (e.g. boson stars, dark matter stars, gravastars), and certain quantum modifications to black holes (e.g. firewalls) are speculated to give out echoes'' or bursts of radiation appearing at regular time intervals due to a perturbation by any infalling matter or field. In particular, these echoes are also expected to appear soon after their formation.

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## Improvements on the methods for searching echoes

Wednesday Nov 08, 2017
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The recent detections of merging black holes allow for observational tests of the nature of these objects, such as searching for the GW echo signals proposed in some models. Tentative evidence for these was presented, found in an analysis based upon methods for GW data analysis as demonstrated on the Ligo Open Science Center. We present the results of characterising these method's behaviour when applied to the specific form of the echo signals, and address problems and improvements based on our findings.

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## Echoes from the Abyss: Tentative Evidence for Planck-Scale Structure at Black Hole Horizons

Wednesday Nov 08, 2017
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In classical General Relativity (GR), an observer falling into an astrophysical black hole is not expected to experience anything dramatic as she crosses the event horizon. However, tentative resolutions to problems in quantum gravity, such as the cosmological constant problem, or the black hole information paradox, invoke significant departures from classicality in the vicinity of the horizon. It was recently pointed out that such near-horizon structures can lead to late-time echoes in the black hole merger gravitational wave signals that are otherwise indistinguishable from GR.

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## Quantifying the evidence for black holes with GW and EM probes

Wednesday Nov 08, 2017
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## LECTURES ON-DEMAND

### Jocelyn Bell Burnell: University of Oxford

Speaker: Jocelyn Bell Burnell