Objective Observations of the temperature fluctuations in the cosmic microwave background (CMB) have transformed cosmology into a quantitative science. This revolution has led to a detailed understanding of the geometry and composition of the universe. However, the microphysical origin of the CMB fluctuations remains a mystery. Although quantum-mechanical fluctuations during a early period of inflationary expansion provide a remarkably successful description of the data, a concrete realization of inflation in a fundamental theory of particle physics remains elusive. Moreover, it seems almost certain that the inflationary era involved physics beyond the Standard Model. This is both a challenge and a fantastic opportunity to learn about physics at the highest energy scales from cosmological observations.With the ERC grant I plan to form a group at Cambridge University that will explore both the theoretical foundations and the observational consequences of inflation. A key question that a satisfactory microscopic theory of inflation should answer is why the mass of the inflaton field is much smaller than its natural value. We will search for answers to this question both from the bottom up in effective field theory (EFT) and from the top down in string theory. We will furthermore initiate the first systematic study of large-field inflation, thereby providing the theoretical foundation for inflationary models with observable gravitational waves. To make contact with observations we will then develop an EFT for the inflationary fluctuations as Goldstone bosons of spontaneously broken time-translations. We will compare the predictions of that theory to the latest CMB observations. Finally, we will use the data to pursue two of the central signatures of the physics of inflation: gravitational waves and non-Gaussianity. Fields of science natural sciencesphysical sciencesastronomyobservational astronomygravitational waves Programme(s) FP7-IDEAS-ERC - Specific programme: "Ideas" implementing the Seventh Framework Programme of the European Community for research, technological development and demonstration activities (2007 to 2013) Topic(s) ERC-SG-PE9 - ERC Starting Grant - Universe sciences Call for proposal ERC-2011-StG_20101014 See other projects for this call Funding Scheme ERC-SG - ERC Starting Grant Coordinator UNIVERSITEIT VAN AMSTERDAM EU contribution € 285 391,28 Address Spui 21 1012WX Amsterdam Netherlands See on map Region West-Nederland Noord-Holland Groot-Amsterdam Activity type Higher or Secondary Education Establishments Principal investigator Daniel Baumann (Dr.) Administrative Contact Jo Lansbergen (Ms.) Links Contact the organisation Opens in new window Website Opens in new window Total cost No data Beneficiaries (2) Sort alphabetically Sort by EU Contribution Expand all Collapse all UNIVERSITEIT VAN AMSTERDAM Netherlands EU contribution € 285 391,28 Address Spui 21 1012WX Amsterdam See on map Region West-Nederland Noord-Holland Groot-Amsterdam Activity type Higher or Secondary Education Establishments Principal investigator Daniel Baumann (Dr.) Administrative Contact Jo Lansbergen (Ms.) Links Contact the organisation Opens in new window Website Opens in new window Total cost No data THE CHANCELLOR MASTERS AND SCHOLARS OF THE UNIVERSITY OF CAMBRIDGE United Kingdom EU contribution € 1 208 143,72 Address Trinity lane the old schools CB2 1TN Cambridge See on map Region East of England East Anglia Cambridgeshire CC Activity type Higher or Secondary Education Establishments Administrative Contact Renata Schaeffer (Ms.) Links Contact the organisation Opens in new window Website Opens in new window Total cost No data