Speaker
Description
In General Relativity, the Bondi-Sachs formalism is used to study the energy
emitted from an isolated gravitational system in the form of gravitational waves
as observed at future null-infinity. It introduces the concept of the Bondi
mass, whose decrease is connected to the the news tensor through the famous
Bondi mass loss formula. This work investigates the changes in the Bondi mass
loss formula for axial symmetric systems in a family of scalar-tensor theories
of gravity through the use of a computer algebra system (CAS) based approach.
The software is planned to also automatize the process of calculating mass loss
formulae for further theories of interest, such as Einstein-Gauss-Bonnet gravity
and, eventually, work even without the symmetry requirement. When ready, the
code will be made publicly available under a free license. A priori, it is
expected that the addition of further degrees of freedom shall provide a
predictable and measurable signature of the theory, that may manifests itself,
for example, in gravitational waves observations. Also closely related to the
Bondi-Sachs results is the BMS group, which plays an important role in the
search for a quantum theory of gravity. As such, it is highly interesting to
understand the modifications to the BMS group in theories of gravity beyond
general relativity.