The interior of a neutron star is much less sticky than we thought, because its internal vibrations and nuclear clusters barely talk to each other.
April 25, 2026
Original Paper
Interaction between nuclear clusters and superfluid phonons in the neutron-star inner crust
arXiv · 2604.20725
The Takeaway
Neutron stars are made of the densest matter in the universe, and we previously assumed everything inside them was tightly coupled together. This new calculation shows that the superfluid phonons interact very weakly with the clusters of atoms in the star's crust. This means energy does not move through the star as easily as older models predicted. This discovery changes how we explain the glitches or sudden jumps in a neutron star's rotation speed. It suggests that the internal plumbing of these dead stars is far more complex and disconnected than anyone realized.
From the abstract
The interaction between lattice vibrations of nuclear clusters and superfluid phonons associated with neutron superfluidity plays an important role in the dynamics of the neutron-star inner crust. While this coupling has been discussed mainly within macroscopic approaches such as hydrodynamics and effective field theory, its microscopic origin and the value of the effective coupling constant have remained unclear. In this work, we derive the interaction between nuclear clusters and superfluid ph