How traversable is a traversable wormhole?
Abstract
To answer the above question, we study low-frequency scattering in the four-dimensional traversable wormhole of Maldacena, Milekhin, and Popov. The resulting transmission probabilities reveal that wormhole traversability depends strongly on the nature of the probe. For scalar probes, both neutral and charged, traversability depends on the time scale. On time scales of order the light-crossing time after sending in a signal, the transmission is parametrically suppressed, with most of the incoming signal reflected or temporarily trapped inside the wormhole throat. As time progresses, the trapped signal gradually leaks out, so that at late times the accumulated transmission cross-section approaches one half of the corresponding black hole absorption cross-section. Despite this generic suppression at low frequencies, the transmission spectrum also exhibits resonant frequencies at which transmission becomes perfect. Charged massless fermions tell a very different story. Unlike scalars, they traverse the wormhole with essentially unit probability at low energies. The same mechanism underlies their efficient absorption by magnetic black holes and realizes a channel closely analogous to the Callan-Rubakov effect, revealing unexpected connections with monopole-fermion scattering. Putting everything together, we conclude that scalar probes are best suited for uncovering distinct features of these magnetic wormholes, while charged massless fermions are the ideal carriers of information through them.
Related
- Extracting Energy from a Traversable Wormhole via Magnetic Reconnection: Circular Orbits and the Plunging Region
- Chaotic particle dynamics near a traversable wormhole throat
- Chaotic particle dynamics near a traversable wormhole throat
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- Traversable Wormhole De-singularization: Almost η-Ricci-Yamabe Solitons in Static Spherically Symmetric Imperfect Fluid Spacetimes
BibTeX
@misc{freivogel2026traversable,
title = {{How traversable is a traversable wormhole?}},
author = {Ben Freivogel and Alessandro Fumagalli and Marija Tomašević},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2606.12528},
eprint = {2606.12528},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.12528},
}
RIS
TY - UNPB
TI - How traversable is a traversable wormhole?
AU - Ben Freivogel
AU - Alessandro Fumagalli
AU - Marija Tomašević
PY - 2026
DA - 2026/09/14
PB - arXiv
DO - 10.48550/arxiv.2606.12528
UR - https://arxiv.org/abs/2606.12528
AB - To answer the above question, we study low-frequency scattering in the four-dimensional traversable wormhole of Maldacena, Milekhin, and Popov. The resulting transmission probabilities reveal that wormhole traversability depends strongly on the nature of the probe. For scalar probes, both neutral and charged, traversability depends on the time scale. On time scales of order the light-crossing time after sending in a signal, the transmission is parametrically suppressed, with most of the incoming signal reflected or temporarily trapped inside the wormhole throat. As time progresses, the trapped signal gradually leaks out, so that at late times the accumulated transmission cross-section approaches one half of the corresponding black hole absorption cross-section. Despite this generic suppression at low frequencies, the transmission spectrum also exhibits resonant frequencies at which transmission becomes perfect. Charged massless fermions tell a very different story. Unlike scalars, they traverse the wormhole with essentially unit probability at low energies. The same mechanism underlies their efficient absorption by magnetic black holes and realizes a channel closely analogous to the Callan-Rubakov effect, revealing unexpected connections with monopole-fermion scattering. Putting everything together, we conclude that scalar probes are best suited for uncovering distinct features of these magnetic wormholes, while charged massless fermions are the ideal carriers of information through them.
ER -