MSc Thesis Defence: Self-Gravitating Anisotropic Fluids

MSc Candidate

Tom Cadogan

Abstract

As the densest material environment in the known universe, neutron stars are perfect playgrounds for studying matter at irreproducibly large densities. In the superfluid regions of the body, nucleon interactions are expected to create temporary “molecules” whose preferred orientation gives rise to a secondary principle stress. However, the present literature falls short of capturing this, characterizing the resulting anisotropy with equations of state violating the weak equivalence principle and a fluid mechanics only applicable in spherical symmetry.
Here, we construct a self-gravitating anisotropic fluid theory from a variational principle inspired by the theory of liquid crystals and obtain a fluid action easily promoted to the relativistic setting. The description of the underlying anisotropy is then obtained without imposition, and the variational approach frees all symmetry requirements. The fluid theory is then applied to an equilibrium stellar model, from which general effects of anisotropy are observed.

Examination Committee

• Dr. Robert Wickham, Chair
• Dr. Eric Poisson, Advisor
• Dr. Alexandros Gezerlis, Graduate Faculty
• Dr. Luis Lehner, Graduate Faculty