The Universe in Light of Fundamental Physics

Lead Research Organisation: King's College London
Department Name: Physics

Abstract

Particle physics and cosmology are merging. In recent years, the cross-pollination of ideas between the fields has accelerated, fueled by the availability of a wealth of new raw astrophysical data and increased realization of the intimate theoretical connection between particle physics and cosmology. Now that the LHC is online, particle physics is returning the favour with high-quality data on the building-blocks of cosmology. With the coming release of data from the PLANCK satellite and many balloon experiments, the Advanced LIGO gravitational-wave detectors, the AMS-02 space-based particle detector, the Dark Energy Survey (DES), and many other experiments searching for dark matter, this cross-pollination of ideas and data is destined to continue.

The scientific programme proposed here by the Theoretical Particle Physics and Cosmology (TPPC) Group in the Physics Department of King's College London is focused on the the analysis and interpretation of data from observational cosmology and high-energy astrophysics using insights from fundamental physics.

Although the LHC now makes possible direct studies in the laboratory of fundamental physics processes at unprecedented energies, these are eclipsed by the energies attained in the Very Early Universe and in the ultra-high-energy cosmic rays that may be produced by Active Galactic Nuclei (AGNs), gamma-ray bursters (GRBs), supernovae, black holes and pulsars. The cosmic microwave background (CMB) and violent astrophysical events therefore provide unique laboratories for studying new fundamental physics. However, while searching for observational signatures of new physics, one must model known physics accurately, taking into account the information provided by the LHC and other accelerators. For example, the wealth of new data on the CMB and large-scale structure (LSS) necessitates the development of new analysis tools to probe and interpret possible signatures of new physics such as primordial non-Gaussianities and small neutrino masses, so as to distinguish them from more conventional phenomena. Likewise, searches for dark matter require accurate modelling of dark matter halos in order to calculate reliably density and velocity distributions as well as to probe for deviations from the usual weakly-interacting dark matter paradigm, such as self-interactions. Moreover, high-energy emissions from astrophysical sources provide unique opportunities to search for new physics that complement particle colliders and could yield striking observational signatures.

Planned Impact

These projects will enable the King's Theoretical Particle Physics and Cosmology Group to have significant global impact at the interfaces between early-Universe cosmology, high-energy astrophysics and fundamental physics.

1) Predictions and Observations of Non-Linear Physics in the Early Universe: We will develop new methodologies and observables to probe the Early Universe, enlarging the theoretical and observational window into theories of the Early Universe. We will build a full general relativistic numerical code with adaptive mesh refinement that is applicable to cosmological problems -- a code we intend to make publicly available. We will test and confirm (or disprove) several conjectures of strong gravity physics in cosmology such as the formation of black holes in cosmological collisions, and the stability of Black Rings.

2) Astrophysical Modelling of Dark Matter: We will obtain a greater understanding of the distribution of dark matter in galaxies. We will create new methods of analysing data based on higher moments of the Jeans equation, enabling us to constrain further the dark matter parameter space and provide an additional astrophysical window into the nature of dark matter, be it cold, warm, self-annihilating or
self-interacting. We will measure the expansion history of the Universe with high-energy gamma rays and place independent constraints upon the equation of state of dark energy (or equivalently the nature of modified gravity). We will test fundamental physics by looking for the observational effects of axion-like dark matter candidates.

3) Signatures of Fundamental Symmetries in Astrophysics: We will obtain new and better contraints on the amplitude and type of Lorentz Symmetry violations. We will obtain the strongest possible astrophysical constraints on the principle of equivalence with time-varying sources of high-energy particles. We will develop new modeling techniques of energy astrophysical sources, and test fundamental symmetries using data from Fermi, HESS II and CTA.

These projects will have significant impact on several academic communities: observers seeking to characterize phenomena in the early Universe, astrophysicists seeking to characterize dark matter, general relativists seeking a new generation of numerical tools, and particle physicists developing theories beyond the Standard Model.

Publications

10 25 50
 
Description We have released GRCHOMBO to the public domain through the BSD-3 License. This is one of the goals of the grant.
Exploitation Route The code is now being investigated by several different research groups who might choose to adopt it.
Sectors Other

URL http://www.grchombo.org
 
Description FQXi Large Grant Round 2016
Amount $121,462 (USD)
Organisation Foundational Questions Institute (FQXi) 
Sector Learned Society
Country United States
Start  
 
Description COSMOS Consortium 
Organisation STFC DiRAC COSMOS Shared Memory Service (HPC Facility Cambridge)
Country United Kingdom 
Sector Academic/University 
PI Contribution I am board member of the COSMOS consortium. In addition to HPC concerns, we are also collaborating on the public release and development of the numerical code GRCHOMBO of which I am a primary developer and founder.
Collaborator Contribution Provide computing resources. Technical and development work on GRCHOMBO.
Impact Several scientific papers written with the use of the facility, and with technical assistance from the consortium members. Organized a conference on numerical cosmology. Technical and development work on GRCHOMBO.
Start Year 2010
 
Description GRCHOMBO Code Collaboration 
Organisation Argonne National Laboratory
Country United States 
Sector Academic/University 
PI Contribution I am one of the three co-founders of the GRCHOMBO code collaboration. The code is a state of the art numerical relativity code that is publicly available. My research group is very active in maintaining and contributing to the code.
Collaborator Contribution They contribute to the development of the code.
Impact GRCHOMBO, a multi-purpose numerical relativity code, is now open sourced and available.
Start Year 2011
 
Description GRCHOMBO Code Collaboration 
Organisation Intel Corporation
Country United States 
Sector Private 
PI Contribution I am one of the three co-founders of the GRCHOMBO code collaboration. The code is a state of the art numerical relativity code that is publicly available. My research group is very active in maintaining and contributing to the code.
Collaborator Contribution They contribute to the development of the code.
Impact GRCHOMBO, a multi-purpose numerical relativity code, is now open sourced and available.
Start Year 2011
 
Description GRCHOMBO Code Collaboration 
Organisation Queen Mary University of London
Country United Kingdom 
Sector Academic/University 
PI Contribution I am one of the three co-founders of the GRCHOMBO code collaboration. The code is a state of the art numerical relativity code that is publicly available. My research group is very active in maintaining and contributing to the code.
Collaborator Contribution They contribute to the development of the code.
Impact GRCHOMBO, a multi-purpose numerical relativity code, is now open sourced and available.
Start Year 2011
 
Description GRCHOMBO Code Collaboration 
Organisation University of Cambridge
Country United Kingdom 
Sector Academic/University 
PI Contribution I am one of the three co-founders of the GRCHOMBO code collaboration. The code is a state of the art numerical relativity code that is publicly available. My research group is very active in maintaining and contributing to the code.
Collaborator Contribution They contribute to the development of the code.
Impact GRCHOMBO, a multi-purpose numerical relativity code, is now open sourced and available.
Start Year 2011
 
Description GRCHOMBO Code Collaboration 
Organisation University of Oxford
Country United Kingdom 
Sector Academic/University 
PI Contribution I am one of the three co-founders of the GRCHOMBO code collaboration. The code is a state of the art numerical relativity code that is publicly available. My research group is very active in maintaining and contributing to the code.
Collaborator Contribution They contribute to the development of the code.
Impact GRCHOMBO, a multi-purpose numerical relativity code, is now open sourced and available.
Start Year 2011
 
Title GRChombo Numerical Relativity Code 
Description Full Adaptive Mesh Refinement capable Numerical Relativity code. 
Type Of Technology Software 
Year Produced 2018 
Open Source License? Yes  
Impact Code is now in production phase with science output forthcoming by the beginning of 2015. Code is released under BSD-3 License in 2018. 
URL http://www.grchombo.org
 
Description Article for New Scientist 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Wrote an article on general relativity and quantum mechanics for the popular science magazine New Scientist.
Year(s) Of Engagement Activity 2015
 
Description Interviewed by BBC4 as part of Science Program 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact I was filmed by BBC4 as part of a science special hosted by Prof Jim Al-Khalili.
Year(s) Of Engagement Activity 2016
 
Description Interviewed by ITV. 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Interviewed by ITV for 6 o'clock news for Big Ben clock "anomaly".
Year(s) Of Engagement Activity 2015
 
Description Interviewed on Radio by US based National Public Radio 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact I was interviewed on live radio (US National Public Radio) on the Colin McEnroe show.
Year(s) Of Engagement Activity 2016
URL http://wnpr.org/post/multiplicity-multiverse
 
Description Public Talk 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Public talk in a New Scientist event.
Year(s) Of Engagement Activity 2016
 
Description Public Talk at British Library 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Gave public science talk at British Library
Year(s) Of Engagement Activity 2015