Gravitational waves and perturbations of neutron stars

Abstract

Gravitational waves are predicted by general relativity and there have been already indirect observations of these waves, as in the case of the Hulse-Taylor binary pulsar. Gravitational wave detectors are being built, commissioned and further improved in many countries of the world. This effort is also present in Brazil, where the Mario Schenberg spherical detector is developed.Isolated neutron stars are also promising sources of gravitational waves. Perturbations in the stellar fluid can cause oscillations coupled to the emission of gravitational waves. In this project, the main focus will be on the f (fundamental) and r (rotational) modes of non-radial oscillations, which are related to possible instabilities and abundant emission of gravitational waves by neutron stars. This study also allows us to obtain precious information about the internal structure of the neutron star, and the equation of state of nuclear matter in supra-nuclear densities unlikely to be achieved in any terrestrial laboratory. In this way, the results obtained from this multidisciplinary are also relevant to nuclear and particle physics. Prof. Yoshida from University of Tokyo is a well-known expert in oscillations of neutron stars. The proposed visit to the research group of Prof. Chirenti in the Center for Mathematics, Computation and Cognition at the Federal University of ABC will be of great value to their ongoing collaboration and the related research projects. The interaction of Prof. Yoshida with graduate students in this field will be another capital point of the visit. The interaction with other research groups in the state of São Paulo will also be encouraged, with proposed short visits to related groups working in USP, UNICAMP and INPE. (AU)