## Modern Developments in General Relativity and their Historical Roots

**10-12 Jan 2017, London, King's College, UK**

The conference will give an account of modern developments in general relativity and in particular, there will be lectures on

- the recent discovery of gravitational waves at LIGO, the status of such future experiments and the theoretical calculation that underpin such effects,
- the roles of asymptotic symmetries in general relativity, such as the Bondi-Metzner-Sachs (BMS) group, and its applications that include the progress made towards understanding the information paradox for black holes,
- the status of the uniqueness theorems in four and higher dimensions, and the investigation of the classical stability of black holes,
- the quantum fluctuations in the early universe and their role in structure formation.

As is very well known, general relativity was discovered by Einstein in 1915. However, apart from some important early developments, such as Einstein's work on gravitational waves, the discovery of the Schwarzschild black hole and the cosmological models, it went through a very long dormant period which ended around the mid 1950's. There was a lack of understanding of what were the observables in such a theory, and this even led to the widespread impression that it was not really a physically predictive theory at all. The modern very active subject that general relativity has become, can be traced back to the work of a small number of researchers and institutions. One of the most important centres was the general relativity group in the Department of Mathematics at King's College London, created by Bondi. Members of this group initiated many of the main themes of this conference, including Pirani's work on gravitational waves, which provides the theoretical foundation of the LIGO experiment, Bondi and Sachs's investigation of symmetries of asymptotically flat spacetimes, known as the BMS group, the formulation of Penrose diagrams, Robinson's work on the uniqueness theorem of black holes, and the study by Davies, Ford and others of quantum effects in curved spacetimes. The conference will also feature a number of talks to recall this period of research at King's.

The Nobel prize in 2017 was awarded for the direct measurement of gravity waves and the report on the scientific background.

https://www.nobelprize.org/nobel_prizes/physics/laureates/2017/advanced-physicsprize2017.pdf

makes extensive references to the work of Bondi and Pirani. The lectures of Daniel Kennefick, David Robinson and Roger Penrose at the conference include accounts of the developments on the theoretical prediction of gravity waves in the 1950’s and 1960's.

The lecture of Thibault Damour explains how the gravitational waves from colliding black holes, as measured by LIGO, were computed from general relativity. While the lecture of Steven Fairhurst gives an account of the LIGO results.

The lectures of Piotr Chrusciel, Mihalis Dafermos, Stefan Hollands, and Harvey Reall concern more modern developments in general relativity while those of Larry Ford and Viatcheslav Mukhanov discuss quantum effects in curved spacetime.

It is intended that this website will contain additional documents and that it will become an archive on the historical development of general relativity.

Links: People in the Mathematics Department at Kings who are associated with General Relativity

**Videos of the conference may now be found on http://grkcl.org/node/17**

**Main Organizers:** George Papadopoulos, Peter West

**Local Organizers:** Nikolay Gromov, Sebastian Lautz