This is the astro-ph blog of the Theoretical Modelling of Cosmic Structures group (TMoX) at the Max-Planck-Institute for Extraterrestrial Physics. We are an independent Max-Planck Research Group focusing on the various aspects in the formation and evolution of galaxies. Part of our focus is on the formation and evolution of early-type galaxies, super-massive black holes, the formation of the first structures in the universe and the enrichment history of the Universe. We are theoreticians using analytic modelling as well as numerical simulations in our work.

The CosmologyCake blog is dedicated to the discussion of research papers and current developments. We will regularly post interesting papers and comment on them. Feel free to leave your comments as well. We encourage authors of discussed papers to post replies if they wish to. Our aim is to provide a platform to discuss recent astro-ph papers within a wider audience. Please feel free to send papers you would like to be discussed to us at tmoxgroup@googlemail.com.

21 July 2011

Adaptive gravitational softening in GADGET

Authors: Francesca Iannuzzi and Klaus Dolag

Link to paper

The authors describe the implementation of adaptive gravitational softening in GADGET. The softening lenght is a function of the local density, as for standard SPH. A correction to the formulation of the Lagrangian is necessary to reduce noise and preserve the translational invariance.

Applied to cosmological simulations, the enhanced resolution at high densities shows in the increase of particle clustering at small scales, amplitude of the correlation function, and inner profile of massive haloes. This allows to recover the results of higer resolution simulations at much lower computational costs.