I am Professor of Astrophysics in the Extragalactic Astronomy and Cosmology research group of the Jodrell Bank Center for Astrophysics in the School of Physics and Astronomy at The University of Manchester.

I am currently advertising for a postdoctoral researcher to work with me on cosmology with the Dark Energy Survey funded by my ERC Consolidator Grant, and on LSST shear measurement. Please get in touch if you are interested.

We recently heard from STFC that a team of us from STFC research and N8 Agrifood have been awarded funding to run the STFC Food Network+. We are very excited to have resources available to bring food researchers together with STFC researchers to solve food challenges using expertise from STFC areas. This will launch in January.

Currently the biggest puzzle in cosmology is the nature of the dark energy which seems cause the mysterious accelerated expansion of the Universe. Weak gravitational lensing can tell us about the dark energy because it shows us the dark matter distribution. The dark matter clumps less as time passes if there is more dark energy, since the dark energy is stretching the universe out and counteracting the attraction by gravity.

Compared to other cosmological probes, gravitational lensing has the greatest potential for telling us more about the dark energy. However there are a number of areas which require more work so that the full potential can be reached, and I am concentrating on the following:
  • Accurate measurement of galaxy shapes from images, in the presence of blurring by the telescope and atmosphere.
  • Removal of the contaminating effect of intrinsic galaxy orientations.
  • We only have approximate measurements of the distances to the galaxies ("photometric redshifts").
  • The gravitational lensing signal is determined by averaging over many millions of galaxies, but the optimal statistics have not yet been developed to extract the maximum information.
To learn more about the universe we need observations. I lead the im3shape shear measurement team in the Dark Energy Survey (DES), which has now taken 3 years of data (of 5 years), and I am Project Scientist for the UK Consortium in the Large Synoptic Survey Telescope (LSST).

Here are some lectures I gave to starting cosmology research students at Saas Fee 2014.

To find out more, contact me or members of my group: Emily Hall, Simon Samuroff, Jack Elvin-Poole, Nicolas Tessore, Dale Mellor and Richard Rollins.