Gravito-Meissner Effect in Neutron Star Systems
St George's School
Floor Location : S 185 P
Under the framework of gravito-electromagnetism, which seeks to relate Einstein's equations for general relativity with electrodynamic behavior, the gravito-Meissner effect in neutron star systems is investigated. Experimental evidence shows that neutron stars have superfluid cores, and will thus exhibit behavior analogous to the Meissner effect seen in superconductors, repelling gravitomagnetic fields from companion stars according to the London equations for gravitomagnetism. In the gravito-electromagnetic paradigm, however, the gravitomagnetic field generates a current that induces another gravitomagnetic field in the same direction as the previous; thus, there exists an anti-Meissner effect phenomenon as well. Furthermore, the recursive feedback leads to instability: minute disequilibria would inevitably result in divergence of the current and corresponding gravitomagnetic field. To resolve this inconsistency in gravitomagnetic theory, we consider the effective bulk viscosity in the neutron star core due to non-equilibrium transformation of particles through Urca processes. Bulk viscosity in the gravitomagnetic induced current of star proportionally dissipates the gravitomagnetic field, which is essentially gravitational potential, between the neutron star and its companion stars, preventing divergence of values. By introducing bulk viscosity into the picture, we avoid resorting to evaluating higher order terms for our gravito-magnetic Maxwell equations, which would complicate calculations unnecessarily.