Mechanism of classical wormhole formation

Determine the physical mechanism responsible for the formation of classical wormholes.

Background

The paper notes that, although black-hole formation can be understood under certain gravitational-collapse scenarios, the formation mechanism of a classical wormhole remains unresolved. This issue concerns the physical origin of wormhole spacetimes and is presented as a broader open problem in the context of studying their possible astrophysical signatures, including microlensing.

References

At the same time, the mouth of a wormhole can simulate the behavior of the event horizon of a black hole. Features of the observational characteristics of wormholes include characteristics of accretion disks , models of wormholes with a thin shell, the outer region of which is described by solutions for black holes , characteristics of gravitational lensing in both weak and strong field limits and wormhole shadows . Apart from these, there could be other distinctive properties of wormholes. For instance, wormholes resulting from the merger of two Schwarzschild black holes can emit gravitational waves . Such ring-down emissions can occur also from the perturbations of massive Ellis-Bronnikov wormholes .

— Galactic microlensing by Lobo-Parsaei-Riazi phantom wormhole: Paczyński light curves and probabilistic features  (2608.19757 - Akhtaryanova et al., 20 Aug 2026) in Introduction, paragraph 3