Observational Cosmology

In the last few decades observational cosmology had evolved into a data-rich field. Recent observations of the Cosmic Microwave Background (CMB), gravitational lensing, galaxy maps and supernovae have led to the emergence of a standard cosmological model in which the Universe is geometrically flat and expanding at an accelerating pace. The discovery of the accelerating expansion of the Universe led to a physics Nobel prize in 2011.

The only way to theoretically explain these observations within the context of Einstein’s theory of general relativity is called the standard cosmological model. In this model, the Universe is composed of approximately 4% baryons (stars, planets and us), 22% of dark matter (exotic matter that doesn’t emit or absorb light), and 74% dark energy that drives the Universe’s acceleration. Today the nature of dark matter and dark energy are unknown and additional surveys are required to investigate these further as well as test the laws of gravity itself.

Recent studies have shown that the most powerful way to probe dark matter and dark energy and test general relativity is with improved surveys of gravitational lensing and galaxy maps.

The LASTRO is involved in the theoretical aspects of these cosmological probes, as well as in solving the practical difficulties of galaxy shape measurements which are central to measuring gravitational lensing. LASTRO is also strongly involved in the future Euclid satellite, whose primary aim is to understand the nature of dark energy and dark matter and test general relativity.