ERC Conference 2012

Joanna DunkleyUniversity of Oxford

Fundamental physics from the Cosmic Microwave Background

The hot Big Bang

1929 - Edwin Hubble shows that galaxies appear to be moving away from us. The further away a galaxy is, the faster it moves.

ESO

1964 - Penzias and Wilson first measured the ‘Cosmic Microwave Background’: light from the Big Bang.

• Using WMAP, we measured the contents of the Universe and learnt about its earliest moments (SPIRES most cited papers in 2009 and 2011).

• Only 6 numbers are needed to describe contents and evolution, but have ‘missing’ 95%. The data suggest inflation was the origin of all cosmic structure.

Our big questions:

(1) What is Dark Energy? (2) What is Dark Matter? (3) Did inflation really happen and how?

WMAP satellite: 2001-2011

Solution: look at higher resolution

Goals:•Obtain stronger evidence for inflation in first trillionth of second.

•Measure the number of ‘hot dark matter’ species, and their mass.

•Test whether Dark Energy changes with time.

Atacama Cosmology Telescope

At 5200m, one of driest places on planet6-meter telescope with arcminute resolution, 3000 detectorsBeing upgraded this year to much higher sensitivity camera

Planck satellite: 3rd

mission, up now!

The Planck satellite

ESA mission: 3rd generation satelliteObserved from May 2009 – Jan 2012Second instrument still observing

CharmaineArmitage-Caplan

Graeme Addison

J. Dunkley

PI

Post-docs

PhD students Undergraduates

ERC supports: people; high-performance computing; travel for collaboration.We are theorists; funding people allows us to centrally contribute to projects and lead analyses.

New effect: lensing of the CMB

• The CMB light is bent very slightly by giant cosmic structures• With the Atacama Cosmology Telescope we made the first

detection of CMB lensing! – 2011 PRL paper.

Top 7 2011 highlights in Physics Today, Science News of the Year list

New evidence for Dark Energy

Sherwin, Dunkley, Das et al 2011 PRL

No Dark Energy ruled out –would give too much lensing

Upcoming measurements will test dark energy models or modifications to gravity, and measure neutrino mass.

Found giant cosmic clusters

Using them to understand cosmic evolution – another probe of Dark Energy

Testing early universe physics: how many neutrino species?

Standard particle physics tells us there are three neutrino species.ACT is showing us a small hint of an extra species: are there more than 3?

Planck will shed further light in 2013, then ACTPol is coming – shipping to Chile in July.

J. Dunkley 13/07/10 FPCMB

Looking for inflation with Planck

• ‘Inflation’ is an ultra-rapid expansion of the early universe. Did it happen?

• We are looking for its tiny gravitational wave signal in the polarized CMB using Planck.

• Looking ahead, we are proposing a new telescope in Chile to search for tinier signals.