I am Professor of Cosmology and Director of the Institute of Cosmology and Gravitation at the University of Portsmouth.

I am interested in the physics of the very early universe, less than a second after the Big Bang. My research investigates what primordial fluctuations in the density and metric of spacetime can tell us about the physical processes at work at such early times and high energies.

I teach undergraduate courses in the Faculty of Technology and on the Applied Physics degree in the Faculty of Science.

Inflation? watch this space...

Posted by David Wands on March 17th 2014

Have we seen the first direct evidence for inflation in the very, very early universe? Never mind inflation, have we seen gravitational waves on cosmic scales?

The BICEP2 experiment has presented evidence of primordial gravitational waves, revealed in the pattern of polarised radiation coming from the edge of our observable universe (the cosmic microwave background). The existence of such ripples in the cosmological fabric had been predicted as a "smoking gun" for a period of rapid, accelerated expansion ("inflation") in the very early universe.

Gravitational waves imprint a distinctive curl in the polarisation ("B-modes") which are not produced by other primordial sources, such as density waves. The surprisingly large signal seen by BICEP2 indicates that these primordial ripples were produced by cosmic inflation occurring at fantastically high energy scales, more than a million, million times larger than the energy of particles produced at the LHC in CERN.

The results are surprising because at fist glance they appear to be in tension with data from the ESA Planck satellite released a year ago. Both results quote the size of the gravitational wave signal in terms of a parameter "r". BICEP report a central value of r=0.2 while the Planck collaboration quoted an upper bound of r<0.12. There are uncertainties in both numbers coming from modelling either foregrounds or inflationary parameters. So cosmologists will wait anxiously for the Planck team to release their own polarisation data, expected by the end of this year.

In the meantime the BICEP2 team have staked their claim to be the first to have discovered direct evidence of both primordial gravitational waves and cosmic inflation.

Note added:Here is an interview I gave on the BBC News channel the same day.

Sandi Toksvig visits ICG

Posted by David Wands on February 5th 2013

Sandi Toksvig is the new chancellor of the University of Portsmouth and she came to visit the ICG last month. We told her a bit about the research that goes on in Portsmouth and showed her some of the public outreach activities we do. Here she is with ICG researchers holding an inflatable cosmic microwave background sky. We also showed her how to build a lego universe - a sure-fire hit with any Danish visitors!

Higgs Day

Posted by David Wands on July 4th 2012

Just finished recording a short interview for Radio Solent about the announcement at CERN earlier today of the discovery of a new particle, almost certainly the elusive Higgs boson. I was asked if today is a historic day in the annals of science? I reckon so. The discovery of a new fundamental particle is big news, and the Higgs is the final block (until today the missing link) in the standard model of particle physics. The particle physics community has invested many years, a few billion euros and a lot of credibility in the Large Hadron Collider specifically to discover the Higgs particle. So congratulations to the international community of scientists and engineers at CERN who delivered the goods.

UK Cosmo in Portsmouth

Posted by David Wands on October 2nd 2011

This September the ICG hosted the annual 2-day UK Particle Cosmology meeting, and a Cosmic Superstrings meeting, and an extended cosmology workshop over the following week. The UK Cosmo meetings started 20 years ago with a small group of researchers from Cambridge, Sussex and Imperial meeting in Tom Kibble's office at Imperial College, London. For this meeting we welcomed 90 researchers from around the UK and around the globe, with researchers from the US, Mexico, South Africa and Japan, but we try to keep the same relaxed and informal style, giving students and young postdocs the chance to present their research in a friendly environment.

Local radio interview

Posted by David Wands on March 15th 2011

On Thursday 17th March I am being interviewed on Ronnie Barbour's afternoon show ("The Other One Show") on BBC Three Counties Radio. I think this probably has more to do with the fact that it is National Science and Engineering Week rather than that it is St Patrick's Day (and my Aunt Patricia's birthday). In case you were wondering, the Three Counties are Beds, Herts and Bucks. It just so happens that I grew up in Amersham, Buckinghamshire. The photo above is of the distinctive Market Hall (1682) in Old Amersham.