Research objectives and content
The existing constraints on theories of the formation of structures in the Universe derive largely from the local (low-redshift) distribution of visible matter, whose relation with the mass distribution is still an open question. This uncertainty limits the strength of such constraints. Gravitational Lensing (GL) is directly sensitive to the mass distribution, up to high-redshifts thus can provide new critical tests for cosmogonic theories. Thanks to recent technological developments, systematic observations of GL effects have become feasible and, to exploit this wealth of data, a detailed study of the statistics of those effects in different cosmologies is needed. For this purpose, large high-resolution simulations are essential, because most aspects of GL depend strongly on the complicated geometries of non-linear structures (galaxies and cluster cores) and all the mass distribution along the line of sight has measurable effects. I will work out the statistics of GL using the simulations of the 'Virgo consortium', a collaboration based at Durham having the specific purpose of carrying out large high-resolution simulations of the formation of galaxies and the large-scale structure of the Universe. The results will constrain the cosmological parameters and provide fundamental information on the internal structure of galaxies and clusters, helping interpret existing data and direct future surveys of GL effects. with Dr. Ian Smail, a leading expert on GL, Durham is ideally suited for this research, which will be unique in its scope and accuracy.
Training content (objective, benefit and expected impact)
I will acquire expertise on GL, one of the most active and promising areas in cosmology today, and, also building upon my previous experience, I will increase my skills in working with state-of-the-art numerical and observational data.