Gravity seminar - Magdalena Sieniawska Seminar

Abstract: Neutron stars are currently the only known ‘laboratories’ that allow for testing theories of the densest, cold matter in extreme conditions unattainable at Earth. Description of the neutron star interiors - their equation of state and, subsequently, their internal structure - is however largely unknown. Until the birth of gravitational-wave astronomy, most of our knowledge came from astronomical observations in electromagnetic waves, numerical simulations, but also from terrestrial nuclear experiments, which provide an important link to the low-density regime of nuclear physics. I will discuss how the electromagnetic observations of neutron stars and gravitational-wave detections of inspiraling binary neutron star systems can be used to constrain the equation of state and possible exotic phases of matter. In addition to inspirals and mergers of neutrons stars, there are currently a few proposed mechanisms that can trigger radiation of long-lasting (continuous) gravitational radiation from neutron stars, such as e.g., elastically and/or magnetically driven deformations: mountains on the stellar surface supported by the elastic strain or magnetic field, free precession, or unstable oscillation modes (e.g., the r-modes). I will review how detection of such continuous gravitational radiation will allow us for the better understanding of the neutron stars interiors, especially on their crust physics and elastic properties at low temperatures.