Delve into the fascinating world of gravitational waves in this comprehensive lecture, the fourth in a series. Explore advanced concepts and cutting-edge research in the field of gravitational wave physics over the course of 1 hour and 41 minutes. Gain insights from expert Sebastiano Bernuzzi as he presents the latest developments and theories surrounding these cosmic ripples in spacetime. Enhance your understanding of this groundbreaking area of astrophysics and cosmology through in-depth discussions and explanations provided by a leading researcher at the Galileo Galilei Institute.