Wormhole Shadow: Sharp Angles When Rotating ⚡ экспресс
The shadow of a rotating traversable wormhole of the Teo class with a general redshift function is studied; special attention is paid to the emergence of cusps (sharp features). The shadow boundary is formed by the common envelope of two families of critical orbits: unstable circular orbits outside the throat and orbits on the throat itself. Cusp formation, marking the transition from smooth to sharp boundary, is possible only when the redshift parameter λ varies. A universal critical value λ_c is found that determines the appearance of a cusp. The phase diagram in spin–redshift parameter coordinates demonstrates four morphologies: smooth, cusped, touching 'ears', and throat engulfment. The morphology of the wormhole shadow can serve as an observational diagnostic feature for distinguishing compact objects in future high-resolution images.
A wormhole is a tunnel through space, connecting distant regions of the Universe. Its shadow against a bright gas background was long thought to be as round as that of a black hole. But for a rotating wormhole (one you could actually traverse), the shape of the shadow might be surprising: the edge becomes jagged, like a gear.
If light passing through its throat is strongly 'stretched' (shifting in color toward red), then rotation causes the shadow to develop sharp protrusions. Researchers found a critical threshold: as soon as this stretching reaches a certain value, the shadow abruptly acquires teeth.
Such a 'jagged' silhouette is a key for future telescopes. If instead of a smooth shadow astronomers see a structure with notches, it would point not to a black hole, but to a wormhole.
🎯 Wormholes haven't been discovered yet, but Einstein's equations allow for their existence — just like black holes once were.
🎬 In Interstellar, the journey through a wormhole happened without its shadow — too bad: perhaps it would have looked like a gear.