Jürg Diemand - SNF Professor

	Institute for Theoretical Physics University of Zürich Winterthurerstr. 190 8057 Zürich Switzerland +41 44 63 55820, Office: Y36 K 84 email: diemand 'at' physik.uzh.ch

Research Interests

Computational physics, large scale simulations using particles methods (molecular dynamics / N-Body), structure formation, non-equilibrium systems, phase transitions, emergent properties.

Large scale molecular dynamics simulations

We are currently running very large (up to 8 billion atoms, millions of time-steps) molecular dynamics simulations of homogeneous nucleation from vapor to liquid. Such first order phase transitions are familiar from everyday life (e.g. condensation of vapor in the atmosphere into mist) and play an important role in many areas of science and technology.

In spite of the familiarity and importance, accurate calculations of nucleation rates are still not possible, due to insufficient knowledge about the properties of the smallest droplets (nano-clusters). The unprecedented size of our simulations allows to form significant numbers of droplets under realistic conditions (i.e. without significant depletion of the vapor phase).

For more details and first results see here and here. This project was made possible by a large allocation of computation time (35.5 million CPU hours) by PRACE and support from the SNF.

Dark matter and cosmological structure formation

We use very large N-body simulations to study the formation of dark matter structures in Cosmology. We are especially interested in the dark matter distribution in the halo around the Milky Way (see the via lactea project) and in very "small" scales (a few hundred AU), on which the smallest cold dark matter microhalos form (see e.g. nature.com).

We also apply our simulations results to investigations into the nature of dark matter and its detection, and to the on the distribution of the first black holes and the kinematics of stellar halos and globular cluster systems.

For more details see the papers on astro/ph, SPIRES HEP or NASA ADS or visit the links below:

the via lactea project

high resolution simulations of Milky Way dark matter halos

The first structures in the early universe

See the news articles on nature.com, newscientist.com and astronomy.com.
Additional pictures of these first structures are available here.

More simulation pictures and movies

Pictures and movies illustrating the formation of a LCDM cluster
Illustrations of resolution effects in cosmological N-body simulations