binary compact objects (neutron stars, black holes), deformed compact stars, supernovae
accretion discs around black holes, magnetic instabilities, jet formation
Numerical simulations of compact objects, like (binary) black holes, (binary) neutron stars, their mergers and subsequent formation of a single compact object surrounded by an accretion disk are of paramount importance for contemporary astrophysics (and physics) for several reasons. First, binary neutron-star systems are the best candidate source for explaining a class of gamma-ray bursts, which are in general the most energetic explosions in the Universe. Gamma-ray bursts are observed daily by satellites and telescopes, but their origin is still largely mysterious.
Then, binary neutron-star and/or black-hole systems are powerful sources of gravitational radiation and there are huge experimental efforts worldwide to measure them, especially with laser interferometric detectors. These include the KAGRA detector, which is being built now in Japan. In order to make the detection possible, the accurate knowledge of gravitational waveforms may be of crucial importance.
The measurement of gravitational waves will open a completely new observation window on the Universe, revealing many secrets that are inaccessible to electromagnetic observations (e.g. black-hole dynamics, internal structure of compact stars, internal engine of gamma-ray bursts, big-bang, ...).
In particular, once gravitational waves from binary systems are measured, information about the equation of state of ultra-high-density matter will become available.
Luca Baiotti is currently part of the OUTAP group (Osaka University Theoretical AstroPhysics group) in the Department of Earth and Space Science. Prospective students, in particular, are invited to look at the web pages of the OUTAP group."
Rest-mass density and magnetic-field lines of a black hole surrounded by a disc, a system produced by the merger of binary neutron stars.
Gravitational waveforms of binary neutron-star coalescence, merger, and post-merger.