Echoes from corpuscular black holes

Abstract

In the corpuscular picture of black hole there exists no geometric notion of horizon which, instead, only emerges in the semi-classical limit. Therefore, it is very natural to ask - what happens if we send a signal towards a corpuscular black hole? We show that quantum effects at the horizon scale imply the existence of a surface located at an effective radius $R=R_s(1+\epsilon )$ slightly larger than the Schwarzschild radius $R_s,$ where $\epsilon =1/N$ and $N$ is the number of gravitons composing the system. Consequently, the reflectivity of the object can be non-zero and, indeed, we find that incoming waves with energies comparable to the Hawking temperature can have a probability of backscattering of order one. Thus, modes can be trapped between the two potential barriers located at the photon sphere and at the surface of a corpuscular black hole, and periodic echoes can be produced. The time delay of echoes turns out to be of the same order of the scrambling time, i.e., in units of Planck length it reads $\sqrt{N}\log N.$ We also show that the $\epsilon$-parameter, or in other words the compactness, of a corpuscular black hole coincides with the quantum coupling that measures the interaction strength among gravitons, and discuss the physical implications of this remarkable feature.

arXiv commentV2: 16 pages, 1 figure. Version accepted for publication in JCAP

References in corpus (57)

• Black holes as mirrors: quantum information in random subsystems
• Fast Scramblers
• The Stretched Horizon and Black Hole Complementarity
• The information paradox: A pedagogical introduction
• Testing the nature of dark compact objects: a status report
• The fuzzball proposal for black holes: an elementary review
• Is the gravitational-wave ringdown a probe of the event horizon?
• Echoes of ECOs: gravitational-wave signatures of exotic compact objects and of quantum corrections at the horizon scale
• Echoes from the Abyss: Tentative evidence for Planck-scale structure at black hole horizons
• The observational evidence for horizons: from echoes to precision gravitational-wave physics
• Tests for the existence of horizons through gravitational wave echoes
• Information Loss
• Quantum Compositeness of Gravity: Black Holes, AdS and Inflation
• UV-Completion by Classicalization
• Phenomenological aspects of black holes beyond general relativity
• Low significance of evidence for black hole echoes in gravitational wave data
• Black hole information, unitarity, and nonlocality
• Not quite a black hole
• Generalized Uncertainty Principle and Corpuscular Gravity
• Black Hole Formation and Classicalization in Ultra-Planckian 2 -> N Scattering
• Gravitational wave echoes through new windows
• Exotic Compact Objects and How to Quench their Ergoregion Instability
• Gravitational wave echoes from black hole area quantization
• Echoes in brane worlds: ringing at a black hole--wormhole transition
• Ergoregion instability of exotic compact objects: electromagnetic and gravitational perturbations and the role of absorption
• How does a dark compact object ringdown?
• Scrambling in the Black Hole Portrait
• Echoes of compact objects: new physics near the surface and matter at a distance
• Quasinormal mode oscillations in an analogue black hole experiment
• Analytical model for gravitational-wave echoes from spinning remnants
• Echoes from Quantum Black Holes
• Analytical template for gravitational-wave echoes: signal characterization and prospects of detection with current and future interferometers
• Echoes from the Abyss: A highly spinning black hole remnant for the binary neutron star merger GW170817
• Matter and gravitons in the gravitational collapse
• On Reflectivity of Quantum Black Hole Horizons
• Can we observe fuzzballs or firewalls?
• Classicalization of Gravitons and Goldstones
• Nonlocal star as a blackhole mimicker
• Quantum corpuscular corrections to the Newtonian potential
• Phenomenology of GUP stars
• Testing Quantum Black Holes with Gravitational Waves
• Black holes as self-sustained quantum states, and Hawking radiation
• Non-Thermal Corrections to Hawking Radiation Versus the Information Paradox
• Thermal corpuscular black holes
• Effective Field Theory of Black Hole Echoes
• Are gravitational wave ringdown echoes always equal-interval ?
• Bootstrapping Newton Gravity
• Nonlocality amplifies echoes
• Spectral Lines of Quantized, Spinning Black Holes and their Astrophysical Relevance
• Area Law Micro-State Entropy from Criticality and Spherical Symmetry
• Global and Local Horizon Quantum Mechanics
• Bootstrapped Newtonian stars and black holes
• Quantum black holes in bootstrapped Newtonian gravity
• Quantum Nature of Black Holes: Fast Scrambling versus Echoes
• Strong Coupling and Classicalization
• Horizonless ultracompact objects and dark matter in quadratic gravity
• On echo intervals in gravitational wave echo analysis

Cited by in corpus (4)

• Black-hole microstate spectroscopy: ringdown, quasinormal modes, and echoes
• Tidal response and near-horizon boundary conditions for spinning exotic compact objects
• Novel triple barrier potential for axial gravitational perturbations of a family of Lorentzian wormholes
• Massive fields affected by echoes: New physics vs. astrophysical environment