Ondas gravitacionais: construção teórica e emissão por corpos rígidos

Abstract

Gravitational Waves (GWs) emerged in the scientific landscape as a robust prediction of General Relativity in 1916, when Einstein solved differential equations sets of the theory using perturbations in the metric. This result indicated that GWs would be small propagating distortions in space-time, generated by the rotations of binary systems and rigid bodies, such as neutron stars and black holes, as well as by super-energetic events in space exemplified by celestial body mergers. However, due to the high technological demand for their detection, Gravitational Waves were only directly observed in 2015 by the LIGO detectors in the United States, with confirmation following in 2016. In the period between prediction and detection (1916-2015), various theoretical predictions were formulated regarding the properties of GWs and their impacts on Astrophysics and Cosmology. An exemplary case is the 1993 Nobel Prize-winning work of Russell Alan Hulse and Joseph Taylor, who, through continuous observation of the neutron star binary PSR 1913+16 [1], made a significant discovery: the binary system is radiating energy at the same rate predicted by general relativity for the emission of gravitational waves, causing the two stars to slowly spiral towards each other. This discovery represents the first indirect evidence of the existence of gravitational waves.