4 papers
A fast spectral-multigrid Poisson solver in non-Cartesian geometries
Ankush Mandal, Oliver Gressel, Udo Ziegler +1
Accurate and efficient computation of self-gravity is essential in astrophysical fluid dynamics, particularly in spherical and cylindrical geometries where large radial dynamic ran…
Formation of spirals in early stage protoplanetary discs
Marc Van den Bossche, Oliver Gressel
Class II protoplanetary discs feature numerous non-axisymmetric substructures like spirals and the underlying mechanisms for their formation are still highly debated. Coincidentall…
An efficient spectral Poisson solver for the nirvana-III code: the shearing-box case with vertical vacuum boundary conditions
S. Rendon Restrepo, O. Gressel
The stability of a differentially rotating fluid subject to its own gravity is a problem with applications across wide areas of astrophysics--from protoplanetary discs (PPDs) to en…
Self-gravity in thin protoplanetary discs: 1. The smoothing-length approximation versus the exact self-gravity kernel
S. Rendon Restrepo, T. Rometsch, U. Ziegler +1
Planet-forming discs often contain structures like spiral arms, typically linked to the disc's gravitational forces. In 2D models, an ad hoc softening prescription is commonly used…