Gravitational Lensing as a Cosmological Probe.

I propose to develop new observational probes of cosmology based on gravitational lensing.

The project consists of three themes:

  1. Computer tools will be developed for detecting and measuring small-scale structures in the distribution of dark matter using strong gravitational lenses. This will resolve one of the few persistent conflicts between observations and the predictions of the Cold Dark Matter (CDM) model. The tools will enable the scientific community to take full advantage of present imaging data and future data coming from missions like the proposed EUCLID satellite.
  2. There are several proposed and ongoing surveys designed to measure the weak gravitational lensing of galaxies across large regions of the sky and to measure the redshifts of hundreds of millions of galaxies. To maximize the use of this data I propose a joint analysis of redshift and lensing surveys that will increase the sensitivity to the expansion history of the Universe and separate two observational consequences of dark energy which are otherwise degenerate in weak lensing data alone. This would enable us to verify whether general relativity is valid on cosmological scales. 
  3. The feasibility of studying cosmology using future radio observations of the 21 cm radiation coming from early epochs of the Universe will be investigated. My work has shown that the gravitational lensing of this radiation could provide powerful constraints on the density of the Universe, dark energy's equation of state, and the masses of neutrinos. It should also be possible to actually map the distribution of dark matter across large sections of sky with high fidelity. My goal is to treat the observational noise and systematics realistically and determine what impact telescope design and survey strategy have on the scientific output.

- Dip. di Fisica e Astronomia-DIFA
- Resp. Scientifico: Dr. Robert Benton Metcalf

Start date 01/03/2011
End date 29/02/2016
Duration 60 months
Project Reference 259349
Project cost 1.500.000 EURO
Project Funding 1.500.000 EURO
Area FP7-IDEAS-ERC-Starting
Subprogramme Area ERC Starting Grant - Universe sciences
Contract type Support for frontier research-ERC Starting Grant