"Rotating stars and wave extraction: applications of curvature invariants in astrophysical relativity."
Relatore: Prof. Marco Bruni- Institute of Cosmology and Gravitation, University of Portsmouth,England (UK)
14 Dicembre 2004 ore 15.30
|Weyl scalars appear as curvature variables in the
Newman-Penrose formalism, and are traditionally used
in exact solutions studies. The main application
outside this context is in the Teukolsky formalism
for the study of perturbations of Kerr rotating
black holes. In this talk I will illustrate
how the use of Weyl scalars, and of curvature
invariants constructed from them, turn out to be
useful in two other applications, both of relevance
for the study of sources of gravitational radiation.
The first is a study of relativistic rotating stars.
In this context we want to assess the validity of
the Hartle-Thorne slow-rotation approximation,
comparing with full-GR numerical models, and
to measure the deviation of the spacetime from
Petrov type D, in view of the possible construction
of a Teukolsky-like formalism for the study of
perturbations of rotating stars.
The second is the study of the problem of
"wave extraction" in numerical relativity,
i.e. the problem of invariantly identifying
the radiation signal contained in relativistic
simulations of gravitational wave sources