# Quantum Black Holes in the Sky: from Quantum Gravity to Astrophysics and Cosmology

### APA

Afshordi, N. (2018). Quantum Black Holes in the Sky: from Quantum Gravity to Astrophysics and Cosmology. Perimeter Institute. https://pirsa.org/18020112

### MLA

Afshordi, Niayesh. Quantum Black Holes in the Sky: from Quantum Gravity to Astrophysics and Cosmology. Perimeter Institute, Feb. 27, 2018, https://pirsa.org/18020112

### BibTex

@misc{ pirsa_18020112, doi = {10.48660/18020112}, url = {https://pirsa.org/18020112}, author = {Afshordi, Niayesh}, keywords = {Cosmology}, language = {en}, title = {Quantum Black Holes in the Sky: from Quantum Gravity to Astrophysics and Cosmology}, publisher = {Perimeter Institute}, year = {2018}, month = {feb}, note = {PIRSA:18020112 see, \url{https://pirsa.org}} }

Niayesh Afshordi University of Waterloo

## Abstract

In classical General Relativity (GR), an observer falling into an astrophysical black hole (BH) 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. I outline theoretical and phenomenological arguments for these departures. I will then discuss the tentative observational evidence for Planck-scale structure near BH horizons, seen as "echoes" in LIGO gravitational wave observations, which has now been found by three independent groups. Finally, I present preliminary analysis which strongly suggest formation of a highly spinning black hole within 0.5 second of GW170817 binary neutron star merger, based on prominent echoes in the LIGO strain data.