A theoretical work argues that solutions can be found in a stable wormhole to allow neutron stars to be connected.
We must distinguish between the work in which experiments were supported with specific theories or hypotheses and theoretical works that are highly speculative. Even though these results are self-consistent, that does not mean that Nature has chosen this way of running the universe. Some prestigious journals accept this kind of theoretical work, but if not, that's the ArXiv repository, where you can find this kind of work without a filter, but we can excite the imagination.
The history of the wormhole starts with General Relativity (GR), which allows space-time solutions in the form of pipes that connect two distant regions of the universe through something like a bridge shortcut.
If we could create a wormhole we could even create a time machine. Sufficient to move one of their mouths properly to make it temporarily lags the other. Digging with one hand could come out the other site even before we had time to put on the other mouth. The deadline would be the creation of the system itself and could not travel further back in time to that date. This creates obvious causal paradoxes, so something must be wrong with these models.
There was some academic movement in the late eighties and early nineties on this subject and published several articles on this possibility. Even Carl Sagan used this idea in his novel “Contact”, a work that was later converted into a movie starring Jodie Foster.
The fundamental glue of wormholes is that although the RG allows creation, they are unstable. If ordinary matter falls a little (or a spacecraft with astronauts) or energy (even a little light) on the wormhole causes it to destabilize and collapse into a pair of black holes. To keep open the passage must have a type of matter or negative energy that coats the walls of the tunnel that are not found in nature. So this idea was more or less abandoned years ago. Goodbye to sleep in hyperspace!
Now Vladimir Dzhunushaliev and colleagues at the Eurasian National University of Kazakhstan reopen the issue with an article speculating on ArXiv.
According to his idea, wormholes may form in the center of certain neutron stars and remain open without collapsing. The wormhole would not collapse due to the presence of a mass-less ghost scalar field (technical name of it) and would be completely filled (no gap and therefore there is no passage) of the stellar interior exotic matter, matter here treated as a perfect fluid. The solutions are apparently stable.
From a distance, each of the normal neutron stars seem like a distant observer could not distinguish from any other neutron star without a wormhole. But a neutron star could have a companion with which would be connected by a wormhole.
If so, exotic matter inside, which would behave like a fluid, would go from one star to another producing a kind of resonance between the two stars that would rock. Here comes the good part of the scientific method applied to this idea, since this oscillation could produce bursts of high energy gamma rays that could be measured, at least according to the authors.
The bad news is that according to the authors themselves, there is still some theoretical work done. The experimental one would be in the future.