Models and dynamics of alternative neutron star models

May 2012

Stoytcho S. Yazadjiev and Daniela D. Doneva

In modeling the neutron star interior we are forced to make certain assumptions about the properties of the neutron star matter. Some of these assumptions seem to be natural from a physical point of view, however, there are always uncertainties and suspicions that the assumptions may not be fully correct. As the science history shows there are surprises sometimes - Nature does not always share our notions for "natural". That is why the alternatives should also be investigated.

There are many alternatives to the standard neutron star models. What we considered in our work is neutron stars with anisotropic pressure and mixed neutron-dark-energy starts, i.e. stars containing both normal matter and dark energy. We study the properties of the stars and their stability. As these objects are very compact, their oscillations can produce a significant gravitational wave signal. That is why we study also the oscillation frequencies and the deviation from the standard neutron star models. Thus if gravitational waves from oscillating neutron stars are observed in the future, we can potentially determine the presence of dark energy in the compact objects, or set constraints on the anisotropy in the neutron star interior.

Phys. Rev. D 85, 124023 (2012) arXiv:1203.3963 [gr-qc]
J. Cosmology Astropart. Phys. 1203, 037 (2012) arXiv:1112.4375 [gr-qc]