Gravity Seminars

With the advent of gravitational wave astronomy, our view of the universe has expanded to new and exciting frontiers. One especially promising avenue to explore in fundamental physics through gravitational waves is probing dense nuclear matter contained in neutron stars; observations of gravitational waves sourced by these extremely compact objects allow one to study matter in regimes that we could never replicate on Earth. Compact stars contain finite-size effects, such as tidal deformations, which leave imprints on the gravitational wave signal that describe the internal stellar structure, so studying such effects is crucial to expanding our understanding of matter at the most extreme scales. In this seminar, I shall describe how tidal fields in magnetar systems (neutron stars with incredibly strong magnetic fields) can lead to an interesting interplay between tidal fields and magnetic fields. This interaction is encapsulated in how the tidal field changes the magnetic properties of the star and, in turn, in how the magnetic field of the star changes its tidal deformability properties. I shall also outline an effective field theory formalism to study tidal fields alongside the conventional general relativity formalism. This effective field theory approach proves to be a natural arena to identify features of this system which can be difficult to study with the usual spacetime geometric approach alone.