Synopsis: Italian Delicacies Served Up in a Neutron Star Crust

A new way of topologically labeling the pasta phases thought to exist in neutron stars could help researchers sort out how the phases contribute to star cooling.
Synopsis figure
C. O. Dorso et al., Phys. Rev. C (2012)

The matter in the outermost layer, or “crust,” of a neutron star (the remnant of a supernova) is believed to host a variety of phases in which dense regions of nucleons are filled with voids of lower density. The presence of the phases, euphemistically referred to as “nuclear pasta” because of their resemblance to the shapes of lasagna, gnocchi, and spaghetti, may affect the emission of neutrinos, the primary mechanism by which the neutron star cools. In Physical Review C, Claudio Dorso of the University of Buenos Aires, Argentina, and colleagues report that a set of topological and geometric descriptors can accurately identify each pasta phase predicted by dynamical simulations, a labeling scheme that could be used to directly map the shape of a pasta phase to its effect on neutrino emission and neutron star cooling.

Dorso et al. classify a particular pasta phase by defining its volume, area, mean curvature, and its Euler characteristic—a number that represents the phase’s topology. Although pasta phases have long been studied theoretically, the authors’ calculations are some of the first to use a classical molecular dynamics model that is consistent with low- to medium-energy nuclear reactions. Moreover, they make no initial assumptions about the phase structure, which should help clarify the balance of forces and parameters that lead to the formation of each phase. – Joseph Kapusta


Announcements

More Announcements »

Subject Areas

AstrophysicsNuclear Physics

Previous Synopsis

Atomic and Molecular Physics

Cooling Neutral Atoms in Optical Tweezers

Read More »

Next Synopsis

Chemical Physics

Testing the (Heavier) Waters

Read More »

Related Articles

Synopsis: Anisotropy Limits for the Universe
Cosmology

Synopsis: Anisotropy Limits for the Universe

A new study of the cosmic microwave background places the strictest limits to date on a rotating Universe and other forms of cosmic anisotropy. Read More »

Viewpoint: Uncovering a Quantum Phase Transition in Nuclei
Nuclear Physics

Viewpoint: Uncovering a Quantum Phase Transition in Nuclei

Simulations predict that the ground states of certain light nuclei lie near a quantum phase transition between a liquid-like phase and a phase involving clusters of alpha particles. Read More »

Viewpoint: Unlocking the Hidden Information in Starlight
Astrophysics

Viewpoint: Unlocking the Hidden Information in Starlight

Quantum metrology shows that it is always possible to estimate the separation of two stars, no matter how close together they are. Read More »

More Articles