# Balzan Prize Project

The path to the solution of the relativistic two-body problem, and its impact in observing gravitational waves from compact binary systems

In 2021, Alessandra Buonanno received the Balzan Prize in the field of "Gravitation: physical and astrophysical aspects". Half of the prize money will be used to promote young scientists, notably by supporting a postdoc researching historical and philosophical aspects of solving the two-body problem in General Relativity, by organizing workshops, and by a dedicated visitor program.

## The project at a glance

The project focuses on the history of the solution of the two-body problem in General Relativity in the last 40 years, with particular emphasis on

- the approximated analytical solutions,
- the numerical solution,
- the interface with numerical relativity, and
- the role that the analytical and numerical-relativity methods have played in the discovery of gravitational waves by the LIGO Scientific Collaboration and the Virgo Collaboration in 2015.

This research will close a crucial gap in the literature on the history of the relativistic two-body problem, as the latter has thus far focused entirely on the work by Einstein and collaborators in the late 1920s and in the 1930s. However, many of the questions posed by Einstein and his collaborators were only answered in the last 30 years, other questions and concepts posed by Einstein have been made more precise, and yet others remain unanswered still.

The project is of a pioneering nature in that it will bring Einstein scholars (historians and philosophers of science) together with those who have succeeded Einstein in working and solving the problem of motion in General Relativity for binary systems composed of black holes and/or neutron stars.