Working at OCA in Numerical Cosmology
The European Research Council (ERC) has decided to fund the project “Astrophysics for the Dark Universe: Cosmological simulations in the context of dark matter and dark energy research” at OCA (PI: Oliver Hahn). Various Postdoc and PhD positions will be available in the context of this project. In this project, we will focus on modeling dark matter using new phase space techniques, improve the way initial conditions for cosmological simulations are generated and disseminated, investigate baryonic effects on cosmological observables, and address fundamental problems in using numerical simulations in the precision era of cosmology. Additional ideas and areas of expertise will be brought in by the growing number of members of our group. If you are interested in joining this exciting effort and working with us (now or later), please don't hesitate to contact me.
The Observatoire de la Côte d'Azur (OCA) is a historical observatory located right above the beautiful city of Nice, France, overlooking the Mediterranian Sea and hosts a wide range of astronomical (cosmology, gravitational waves, planetary science, stellar astrophysics, turbulence and space plasmas, instrumentation and signal processing) and geophysical research. There are large synergies between the new and ambitious numerical cosmology group led by Prof. Hahn and existing research on large-scale structure (EUCLID), research on galaxy clusters, as well as the strong fluid mechanics and plasma groups at OCA. The numerical cosmology group has excellent connections and collaborations with many other leading numerical groups in both Europe and the U.S., from which all future members will also greatly benefit. Last but not least, thanks to being a touristic centre, the airport of Nice connects us extremely well to all important European cities. OCA has a large number of international junior researchers that always warmly welcome new additions and help them with their local integration.
PhD student position in Computational Cosmology
announced 08/2016
The Observatoire de la Côte d’Azur (OCA), located in Nice, France, invites applications for a three-year PhD student position in computational astrophysics and cosmology. The successful candidate would carry out research together with Prof. Oliver Hahn in the context of the project “Astrophysics for the Dark Universe: Cosmological simulations in the context of dark matter and dark energy research” financed by the European Research Council.
The position will be available from fall 2017. A PhD at OCA takes three years. Salary is set by french law and benefits include health care and social security. No teaching duties are associated with this position.
To apply for this position, please send your application, consisting of a cover letter, full curriculum vitae, as well as a brief statement of both past research achievements and future research interests to cosmo-sims-admin@oca.eu . Please also arrange for one to two letters of recommendation to be sent to this address. There is no formal due date for applications to this position. Submissions will be considered until the position is filled. Informal inquiries related to this position can be addressed to Prof. Oliver Hahn (oliver.hahn AT oca.eu).
Master projects
Project 1: Numerical simulations of dark matter in the continuum limit
announced 07/2016
The nature of dark matter is one of the big mysteries of contemporary physics. Still, we know its macrophysical properties well enough to be able to model its dynamics in computers. Due to its very weak interaction scale, dark matter behaves radically different from ordinary matter. Dark matter dynamics is described by the Vlasov-Poisson set of equations, which are typically solved using the N-body method in cosmological simulations. Over the last years, we have developed new methods in which the N-body method is replaced by a new continuum approximation which is able to provide us with radically new insights into the dynamics of the self-gravitating dark matter fluid as it forms structures in the Universe.
In this project, the student will use this new method to study the dynamics of dark matter as it forms structures under its own gravity and will extract relevant quantities (such as from the evolution of the mean velocity and density field to more theoretical concepts from statistical physics) from such simulations that describe the evolution of the dark matter fluid and help us to better understand its properties. This research is at the international forefront of efforts to model Vlasov-Poisson dynamics without particles and the student will also be exposed to running simulations on supercomputers. It is strongly recommended that the candidate has a good background in programming (C/C++/Python) and preferably a basic knowledge of statistical physics or fluid mechanics. Depending on motivation and performance, the student may continue this project as a PhD thesis at OCA (funding for a 3 year PhD thesis beginning in fall 2016 exists already, see above).
To apply for this position, please send your application, consisting of a cover letter and full curriculum vitae to cosmo-sims-admin@oca.eu . Please also arrange for one letter of recommendation to be sent to this address. Please contact Prof. Oliver Hahn (oliver.hahn AT oca.eu) if you have any questions.
Project 2: Numerical simulations of massive galaxy clusters
announced 07/2016
Clusters of galaxies are sensitive probes of the cosmology of our Universe. To leverage their power, it is imperative to understand better the properties of their hot plasma and thus ultimately how we can relate their observational appearance in X-ray and microwave observations to the cluster mass. Cosmological hydrodynamical simulations are the tool of choice to identify the relevant astrophysical processes that shape the intra-cluster medium. These processes range from energy injection by supermassive black holes to hydrodynamic processes and magnetic fields. My group carries out such multi-physics cosmological simulations using the adaptive-mesh refinement code RAMSES.
In this project, the student will analyse existing simulations, and also perform new simulations if time permits. He/she will then confront these simulations with existing observational data from X-ray and microwave (thermal SZ) observations. The student will learn how to analyse such adaptive mesh simulations, deal with very large datasets and how to generate simulated observations as well as how such simulations are carried out at supercomputing facilities. In addition, our group at OCA contains many experts on observations of galaxy clusters with which the student will be able to interact in this project thus complementing the theoretical aspects of the project with first-hand knowledge from observers. It is strongly recommended that the candidate has a good background in programming (C/C++/Python) and preferably a basic knowledge of astrophysics and cosmology. Depending on motivation and performance, the student may continue this project as a PhD thesis at OCA (funding for a 3 year PhD thesis beginning in fall 2016 exists already; see above).
To apply for this position, please send your application, consisting of a cover letter and full curriculum vitae to cosmo-sims-admin@oca.eu . Please also arrange for one letter of recommendation to be sent to this address. Please contact Prof. Oliver Hahn (oliver.hahn AT oca.eu) if you have any questions.
