Cosmology and extragalactic astronomy
The Nordic Optical Telescope (NOT) at the island of La Palma.
About the section
The section for Cosmology and Extragalactic Astrophysics emphasizes the interplay between analysis of data from experiments, numerical simulations and fundamental theory to understand the Universe. We are pursuing questions like:
- What is the origin of our Universe?
- How has the universe evolved, and how will it evolve in the future?
- What are the contents of the Universe?
- How did galaxies form and evolve?
- How was the Universe reionized?
- What is the nature of dark energy and dark matter, and do these things really exist?
- What are the physical laws governing the evolution of the Universe?
Over the last few decades, new observations have greatly improved our knowledge of the cosmos, and a standard model of the Universe has emerged. Still, there are lots of fundamental questions yet to be answered, or even posed. Further advances will rely on both new observations, simulations and theoretical work.
Projects and cooperation
The section presently does research in several, closely interacting, directions:
- Participation in and analysis of data from Cosmic Microwave Background (CMB) experiments
- Fundamental theoretical cosmological research.
- Galaxy formation
In the first research direction, observation, analysis and interpretation of the CMB, the group is heavily involved in the ESA Planck mission, a satellite that was launched in May 2009 and is measuring the CMB fluctuations with unprecedented precision. The group is also participating in the ground based QUIET experiment in the Atacama desert, which is measuring the polarization of the CMB signal. The CMB related activities in the group range from observing strategies and cleaning of raw data to estimating the temperature and polarization power spectrum and the cosmological parameters. Special emphasis has been on deviations from Gaussianity and statistical isotropy.
In the second research direction, fundamental theoretical cosmology, the group studies observational consequences of various models for explaining the accelerating expansion of the universe, both dark energy models and alternative gravity theories, as well as cosmological bounds on the neutrino mass.
The Nordic Optical Telescope is used to observe gravitational lenses, which in turn can provide us with important information on the large-scale matter fluctuations in the universe.