Conic Sections on the Sky: Shadows of Linearly Superrotated Black Holes
arXiv:2405.20181 · doi:10.1103/PhysRevD.111.024054
Abstract
Soft hairs are an intrinsic infrared feature of a black hole, which may also affect near-horizon physics. In this work, we study some of the subtleties surrounding one of the primary observables with which we can study their effects in the context of Einstein's gravity: the black hole shadow. First, we clarify the singular pathology associated with black holes with soft hairs and demonstrate that the metrics of linearly superrotated black holes are free of near-zone pathologies due to appropriate asymptotic falloff conditions being imposed on the event horizon. We then analytically construct the photon orbits around such black holes, derive the shadow equation for near-zone observers, and find that the linear superrotation hairs deform the circular shadow of a bald Schwarzchild black hole into an ellipse. This is in sharp contrast to their supertranslated counterparts, which only shift the position of the center of the circular shadow but do not change its shape. Our results suggest a richness to the observable effects due to the infrared structures of Einstein's gravity.
10 pages, 3 figures, v4. Minor correction to the caption of Figure 1
References in corpus (15)
- 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
- Calculating black hole shadows: Review of analytical studies
- Constraints on black-hole charges with the 2017 EHT observations of M87*
- New symmetries for the Gravitational S-matrix
- Fundamental photon orbits: black hole shadows and spacetime instabilities
- On the Membrane Paradigm and Spontaneous Breaking of Horizon BMS Symmetries
- HPS meets AMPS: How Soft Hair Dissolves the Firewall
- Can we detect a supertranslated black hole?
- Black Hole Shadow with Soft Hair
- The Shadow of Supertranslated Schwarzschild Black Hole