The Cosmology of the Early and Late Universe

Lead Research Organisation: University of Nottingham
Department Name: Sch of Physics & Astronomy

Abstract

Cosmology spans a wide range of physics, from the very small scales and high energies of the early Universe to galaxies and galaxy clusters in the late Universe. The Cosmic Microwave Background (CMB) (relic radiation from the big bang) and supernovae explosions allow us to probe the expansion history and constituents of the Universe. These observations suggest that most of matter in the Universe is composed of exotic dark matter. Furthermore the expansion of the Universe recently started accelerating, rather than continuing to slow down as expected. This late time acceleration could be due to an exotic dark energy component, or a modification of Einstein's laws of gravity. The late Universe has a rich structure of galaxies and galaxy clusters. These structures are believed to form from small initial fluctuations in the matter distribution, generated in the early Universe. However the mechanism responsible for producing these fluctuations is not yet understood. Connecting observations of the late time Universe, with the early Universe and fundamental particle physics is a major outstanding issue for cosmology and one of the main goals of our work. Particle physics and general relativity both break down at extreme energies, where a unified theory of quantum gravity is expected to operate. We will test the observational consequences of such theories. In particular string theory allows superstrings to stretch across the Universe, altering the fluctuations in the CMB, producing gravitational waves, emitting high energy particles and lensing galaxies. We will study the evolution of networks of cosmic superstrings and make accurate predictions for their observational signatures. This work could potentially provide the first evidence for string theory through cosmology. We will also study the cosmology of models which arise from string theory, including the very early Universe and the generation of the primordial fluctuations from which structure form. String theory, and other new particle physics models, also provide us with a dark matter candidate in the form of Weakly Interacting Massive Particles (WIMPs). WIMPs can be detected directly in the lab (via their rare interactions with atoms) or indirectly via the antiparticles and high energy gamma-rays that are produced when they come together and annihilate. They can also be produced in particle colliders such as the LHC. We will develop the tools required to unambiguously detect dark matter and measure its properties. We will also study the astrophysical and cosmological consequences of specific string theory dark matter candidates. We will take a two pronged approach to understanding the physics underlying the observed late time acceleration of the Universe. We will develop techniques which will allow us to test the laws of gravity, and models of dark energy, in both the early and late Universe. We will also continue to explore fundamental physics models which may provide a mechanism for the acceleration. Our research encompasses a wide range of scales and energies. This diversity is met with a corresponding array of techniques to study various phenomena, ranging from quantum gravity to classical dynamics and analytic calculations to numerical simulations using supercomputers.

Planned Impact

The particle physics and astronomy communities as well as the QG community working in cosmology are the obvious group of researchers who will benefit directly from the research proposed in this application. They will benefit in that our intention is to predict observational signatures for a number of Early Universe and Late Universe features. For example we will be determining the polarisation signal for a network of cosmic superstrings as a function of the string tension and coupling. This would be of direct interest to the string theory community as well as the CMB community who are searching for evidence of polarisation signals in the CMB. Similarly in the late universe we intend to develop the most complete parameterisation to date of modified gravity models, the PPF formalism. Through it cosmologists working on CMB and large scale structure surveys will have a means to constrain and possibly rule out classes of models by obtaining the required parameters and comparing them with General Relativity. Through our work on dark matter, we will be providing results of interest both to the experimental particle physics community and the astrophysics community working on dark matter detection. Our work on developing a framework for modeling the dark matter distribution to facilitate the unambiguous detection of dark matter and measure its properties, will be of significance for example for those working with the Cherenkov Telescope Array, as well as other upcoming WIMP indirect detection experiments, which are sensitive to WIMP annihilation in the remnants of WIMP microhalos. Our work on modified gravity emerging from string theory and braneworlds will open up a new avenue of using late universe observations for testing Early Universe physics. It will be of interest and could potentially have a significant impact on string theorists. As well as those directly benefitting from our research, we believe many will benefit indirectly. The graduate students and PDRAs that are trained through these projects often go on to work in industry and finance, taking with them the skill set developed in this research and applying it to new projects. We already have three students who have graduated in the past year and who are now working in climate modelling, finance and modelling wind turbines. There are also clear benefits for the wider public. For example undergraduate students will benefit through the opportunity to do projects with members of the group which will often involve learning about the physics involved in the grant. School and college students will benefit through masterclasses run by members of the group and talks given at schools. Similarly members of the public will benefit from public lectures given by group members in which their work will be discussed, through media activities such as radio and television appearances, as well as the continuing particpation of group members in the highly successful Sixty Symbols project. As mentioned above, the Knowledge Transfer will allow graduate students and PDRAs who have been trained by members of the group to enter the workplace and use their skills to beneift society.

Publications

10 25 50
 
Description In the grant ST/J0003881 our research highlights included the determination of the B-mode polarisation signature from a network of cosmic superstrings - a cosmological test of string theory. We made a signicant contribution to the Planck pre-launch paper which determined the expected LFI polarisation ability and has become the standard used by the planck consortium. By studying the constraints on non-Gaussainity (NG) which arise from Primordial
Black Hole (PBH) formation, we showed how PBH observations would rule out non negligible negative Non-Gaussianity signals. For the first time we constructed a class of observables and matter couplings in spin foam models of Quantum Gravity. We provided the first demonstration that general relativity can be described as an SU(2) gauge theory free from the infamous "conformal mode" problem of the usual metric formulation and this lead to a dramatic simplication of the graviton Feynman rules. We provided a new resolution of the infamous cosmological constant problem (CCP) based on selftuning in Horndeski's most general scalar-tensor theory of gravity. We created the Parameterized Post-Friedmannian (PPF) framework for model-independent testing of gravity and dark energy on cosmological scales. We ruled out a popular class of massive gravity models by demonstrating that they lead to a break down of predictability at unacceptably large distances in the earth's gravitational environment. We completed a highly cited review of modified theories of gravity that has quickly become the standard reference in the field. We presented a new formulation of a model-independent parameterisation of the WIMP momentum distribution which will allow the WIMP mass to be measured accurately using data from future direct detection experiments.
Outside of academic breakthroughs we continued to train PhD students and Postdoctoral Fellows through our research and lecture programmes we ran. Members of the programme contributed significantly to Outreach activities including Sixty Symbols and Numberphile Youtube video series, Masterclasses in particle theory and numerous lectures given to schools.
Exploitation Route The research remains ongoing, and subsequent grant applications have been made to secure funding so that we may continue with out work. meanwhile other groups around the world have taken on our research ideas and are extending them.
Sectors Education

 
Description Our work has been published in academic journals and on electronic arXivs. It has been presented at numerous conferences around the world. Some of our work has reached audiences beyond academia as it has been reported through the Youtube channel Sixty Symbols and reached a global audience of well over 500,000.
First Year Of Impact 2011
Sector Education
Impact Types Cultural

 
Description ERC Consolidator Grant
Amount € 1,150,000 (EUR)
Funding ID ERC-2013-CoG-617656 TheMoDS 
Organisation European Research Council (ERC) 
Sector Public
Country European Union (EU)
Start 08/2014 
End 07/2019
 
Description Marie Curie
Amount £166,663 (GBP)
Funding ID 274326 --Anastasios Avgoustidis 
Organisation European Research Council (ERC) 
Sector Public
Country European Union (EU)
Start 10/2011 
End 09/2013
 
Description Nottingham Advanced Research Fellowship
Amount £209,792 (GBP)
Funding ID Univ of Nottingham agresso code: A2RHR1 
Organisation University of Nottingham 
Sector Academic/University
Country United Kingdom
Start 10/2013 
End 09/2016
 
Description PhD studentship
Amount £60,745 (GBP)
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start 03/2013 
End 03/2016
 
Description Reintegration grant
Amount £84,991 (GBP)
Funding ID RH2772 
Organisation European Research Council (ERC) 
Sector Public
Country European Union (EU)
Start 09/2010 
End 09/2014
 
Description Research fellowship
Amount £45,000 (GBP)
Funding ID RF- 2011-633 
Organisation The Leverhulme Trust 
Sector Academic/University
Country United Kingdom
Start 10/2011 
End 10/2013
 
Description Royal Society URF
Amount £426,771 (GBP)
Funding ID 516002.K501/S C/PM/ROG 
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start 10/2008 
End 10/2013
 
Description Royal Society University Research Fellowship
Amount £410,731 (GBP)
Funding ID UF130549 
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start 10/2014 
End 09/2019
 
Description Sir Norman Lockyer Fellowship
Amount £100,000 (GBP)
Organisation Royal Astronomical Society 
Sector Learned Society
Country United Kingdom
Start 10/2011 
End 09/2014
 
Description Starter Grant
Amount £1,042,037 (GBP)
Funding ID FP7- 277570 
Organisation European Research Council (ERC) 
Sector Public
Country European Union (EU)
Start 01/2012 
End 12/2016
 
Description URF
Amount £339,861 (GBP)
Funding ID 516002.K501/S C/PM/ROG 
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start 10/2013 
End 09/2016
 
Description URF
Amount £451,598 (GBP)
Funding ID UF090598 
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start 10/2010 
End 09/2015
 
Description URF
Amount £519,188 (GBP)
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start 01/2013 
End 12/2017
 
Description Visiting Professor
Amount £27,981 (GBP)
Funding ID VP1-2012- 003 
Organisation The Leverhulme Trust 
Sector Academic/University
Country United Kingdom
Start 05/2013 
End 08/2013
 
Description Visiting Professor
Amount £21,787 (GBP)
Funding ID VP2-2010-059 
Organisation The Leverhulme Trust 
Sector Academic/University
Country United Kingdom
Start 06/2011 
End 09/2011
 
Description postdoctoral research fellowship
Amount £127,076 (GBP)
Funding ID RPG-192 
Organisation The Leverhulme Trust 
Sector Academic/University
Country United Kingdom
Start 04/2012 
End 03/2015
 
Description COSMOS 
Organisation University of Cambridge
Department Department of Applied Mathematics and Theoretical Physics (DAMTP)
Country United Kingdom 
Sector Academic/University 
PI Contribution We have access to COSMOS supercomputer
Collaborator Contribution All partners have access to COSMOS to undertake basic research into cosmology
Impact Many publications too numerous to mention
 
Description Dark Energy Survey 
Organisation Fermilab - Fermi National Accelerator Laboratory
Country United States 
Sector Public 
PI Contribution Copeland is on the Theory Working Group
Collaborator Contribution They run the telescope
Impact None yet
Start Year 2012
 
Description Euclid 
Organisation European Space Agency
Department Science and Operations Department
Country France 
Sector Academic/University 
PI Contribution Skordis and Burrage are on Theory working group
Collaborator Contribution Support all elements of the satellite.
Impact None yet
 
Description Planck 
Organisation European Space Agency
Department Science and Operations Department
Country France 
Sector Academic/University 
PI Contribution Adam Moss is on the Planck team, working primarily on polarisation.
Collaborator Contribution All aspects of the project
Impact Huge impact on cosmology.
 
Description Continued Sixty Symbols and Numberphile videos 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Videos made for the General public on maths and physics. reach audiences of well over 1 Million people (Numberphile) and 250,000 (Sixty Symbols)
Year(s) Of Engagement Activity 2009,2010,2011,2012,2013
URL https://www.youtube.com/user/sixtysymbols
 
Description Edinburgh International Science Festival 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Talk sparked plenty of discussion afterwards.

None
Year(s) Of Engagement Activity 2014
 
Description Nottingham Masterclasses 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? Yes
Geographic Reach National
Primary Audience Schools
Results and Impact 60 pupils or so attend the masterclasses

As well as exciting students, it has had an impact on ugd recruitment at Nottingham.
Year(s) Of Engagement Activity Pre-2006,2006,2007,2008,
URL http://www.nottingham.ac.uk/~ppzphy7/webpages/outreach/
 
Description Numberphile videos 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Tony Padilla and Ed Copeland have been involved in a a number of Numberphile videos. A recent one on the sum of the integers has attracted over 3 million hits on you tube.

Hundreds of emails from students and interested people from around the world. Invitations to talk at numerous schools, articles in the NYT, de Spiegel and other major newspapers.
Year(s) Of Engagement Activity 2013,2014,2015,2016
URL http://www.youtube.com/user/numberphile
 
Description School talks 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach National
Primary Audience Schools
Results and Impact Generally very positive feedback from staff and students who appreciate us bringing cutting edge research ideas into the classroom.

See above.
Year(s) Of Engagement Activity Pre-2006,2006,2007,2008,
 
Description Sixty Symbols Videos 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? Yes
Type Of Presentation Keynote/Invited Speaker
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact We have a big impact with these videos receiving thousands of comments on the videos and emails sent thanking us for the work.

See above.
Year(s) Of Engagement Activity 2010,2011,2012,2013,2014
URL http://www.youtube.com/user/sixtysymbols
 
Description Stargazing Live and Infinite Monkey Cage 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? Yes
Type Of Presentation Keynote/Invited Speaker
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Appeared on BBC TV and Radio

Plenty of positive feedback from members of the public and BBC.
Year(s) Of Engagement Activity 2012,2013