I am interested in the turbulence that prevails in astrophysical disks and the instabilities that sustain it. Whereas the magnetorotational instability (MRI) is the main cause of activity in well ionised disks, in more massive colder disks, such as young protostellar disks, gravitational instability (GI) is the leading player. Other than transporting material onto the central star, GI can facilitate the fragmentation of the disk into bound objects which might be the progenitors of the exoplanetary population on very wide orbits. It can also mix and stir up dust and solid material. At certain times and locations the MRI and GI overlap leading to interesting mixed dynamics, in particular outburst behaviour. The FU Ori and EX Lupi phenomena could be linked to this. The figure shows a plasmoid of dense gas encased in a magnetic sheath that has emerged out of magnetic gravitoturbulence.

I am interested in exploring aspects of gravitoturbulence numerically. Topics include fragmentation (of course), the vortical flows and vertical dust transport associated with GI spiral waves, and the interaction of GI spiral waves and magnetic fields: can a large-scale dynamo emerge from gravitoturbulence?

Potential PhD topics include
*Gravitoturbulent dynamos and non-ideal MHD (ambipolar diffusion especially)
*Dust dynamics and spiral waves
*Feathering instability on galactic spiral arms

Recent papers

*Magnetorotational instability and dynamo action in gravitoturbulent astrophysical discs (link)
*Gravito-turbulence and the excitation of small-scale parametric instability in astrophysical discs (link)
*Gravitoturbulence in magnetised protostellar discs (link)