Some black holes might actually look like double-rings or 'crescents' rather than the simple donuts we’ve seen in famous photos.
April 14, 2026
Original Paper
Optical Appearance of Scalarized Kerr-Newman Black Holes with Multiple Light Rings
arXiv · 2604.11652
The Takeaway
Theoretical 'scalarized' black holes can trap light in an extra inner shell, creating a second critical curve in their shadow. If telescopes detect these inner rings, it would be direct evidence of 'new physics' that goes beyond Einstein’s General Relativity.
From the abstract
This study investigates the optical appearance of rotating scalarized Kerr-Newman black holes in the Einstein-Maxwell-scalar theory with exponential coupling. By analyzing equatorial null geodesics, these black holes are classified into six types according to the number and properties of their light rings. Combining slow-rotation analysis with full numerical ray tracing, we investigate images of black holes illuminated by a geometrically and optically thin accretion disk. Unlike the Kerr case, w