Horizonless spacetimes as seen by present and next-generation Event Horizon Telescope arrays

Abstract

We study the capabilities of present and future radio very-long-baseline-interferometry arrays to distinguish black holes from horizonless spacetimes. We consider an example of a horizonless spacetime, obtained by overspinning a regular black hole. Its image is distinct from the image of a Kerr spacetime due to a second set of photon rings interior to the shadow. These photon rings cannot be directly resolved by present and even next-generation Event Horizon telescope arrays, but instead imprint themselves in horizon-scale images as excess central brightness relative to that of a black hole. We demonstrate that future arrays can detect such indirect imprints.

9 pages + references, 5 figures, 3 tables

References in corpus (16)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
• First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
• First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
• First M87 Event Horizon Telescope Results. II. Array and Instrumentation
• First M87 Event Horizon Telescope Results. III. Data Processing and Calibration
• First Sagittarius A* Event Horizon Telescope Results. VI: Testing the Black Hole Metric
• Asymptotic safety casts its shadow
• Evaluation of New Submillimeter VLBI Sites for the Event Horizon Telescope
• The Event Horizon of M87
• The Photon Ring in M87*
• Hybrid Very Long Baseline Interferometry Imaging and Modeling with Themis
• Universal signatures of singularity-resolving physics in photon rings of black holes and horizonless objects
• Thin accretion disks around traversable wormholes
• Destroying the event horizon of a nonsingular rotating quantum-corrected black hole
• Quantum gravity lights up spinning black holes

Cited by in corpus (12)

• Towards a Non-singular Paradigm of Black Hole Physics
• Quasinormal modes-shadow correspondence for rotating regular black holes
• Exploring Nonlinear Electrodynamics Theories: Shadows of Regular Black Holes and Horizonless Ultra-Compact Objects
• Quantum gravity lights up spinning black holes
• A Lensing-Band Approach to Spacetime Constraints
• Ultracompact horizonless objects in order-reduced semiclassical gravity
• Comment on "Regular evaporating black holes with stable cores"
• Scale-invariance at the core of quantum black holes
• Imaging a semi-classical horizonless compact object with strong redshift
• Anisotropic gravastar as horizonless regular black hole spacetime and its images illuminated by thin accretion disk
• A non-local way around the no-global-symmetries conjecture in quantum gravity?
• Horizonless star based on regular black hole with finite radius and its observational signatures