At Nordita, we have a new postdoc position, starting in the fall of 2015, to study the broadly defined subject of properties of particles in turbulent flows with possibilities of applications to the problem of formation of clouds and raindrops on the one hand and the subject of formation of planetesimals on the other hand. The position is for two years. A similar position may be announced two years later.

This position is provided within the framework of the project "Bottlenecks for particle growth in turbulent aerosols" supported by the Wallenberg foundation. The PI of the project is Bernhard Mehlig. The project is a collaboration between A. Brandenburg, and D. Mitra, at Nordita; Kristian Gustavsson, Dag Hanstrop, Bernhard Mehlig, and Stefan Östlund, at the University of Gothenburg; Anders Johansen at Lund Observatory; and Eberhard Bodenschatz, G. Bewley, and H. Xu at the MPI-KS, Göttingen.

The successful candidate will work at the Nordita node of this collaboration with Axel Brandenburg and Dhrubaditya Mitra.

It is necessary to have a PhD (at least to have the thesis submitted) in physics/engineering or a related field. The candidate needs to be experienced in fluid mechanics. Experience in writing numerical codes and working with them will be considered an advantage. Precedence will be given to applicants who have less than five years of post-doctoral experience at the time of application.

Two years. It may be possible to have an extension. The position will start in the fall of 2015.

The applications should include:

1. A curriculum vitae together including a list of publications,
2. Two letters of recommendation,
3. A short research plan aimed at the scientific topic of the project.

The application deadline is 31st of August 2015.

Applications should be filed though our web interface http://apps.nordita.org/. In exceptional cases, you may also send your application via e-mail to dhrubaDOTmitraATgmailDOTcom

A fundamental problem in the Natural and Engineering Sciences is how turbulence accelerates the growth of particles in aerosols. Two paradigmatic examples are how raindrops form in turbulent rain clouds, and how dust around stars aggregates to eventually form planets. Although the aggregation process is understood at the smallest scale where particles grow by diffusion and at the other extreme where large particles grow by sweeping up small ones, there is a fundamental and universal intermediate scale where neither limit applies and where no known mechanism allows the particles to grow at nearly the rates seen in Nature. This is called the "bottleneck problem". In this regime the role of turbulent fluctuations is considered essential, simple models cannot be used, and direct numerical simulations become difficult or impossible. Experiments in this regime are also very difficult, precisely since they must refer to a turbulent environment. The bottleneck problem is therefore at the forefront of theoretical research in and at the boundary between fluid mechanics and statistical physics. Relevant experimental techniques must take account of both macroscopic and microscopic length scales.

Nordita - The Nordic Institute for Theoretical Physics

Nordita was founded in 1957 as a Nordic institute in theoretical (atomic) physics on the premises of the Niels Bohr Institute at Copenhagen University and is since 2006 in Stockholm under the auspices of Stockholm University (SU) and the Royal Institute of Technology (KTH). Nordita is located at the AlbaNova University Center, situated in the immediate vicinity of the two universities.

Note also corresponding positions in Gothenburg for a post-doc (SE) and a PhD student (SE).