Swansea University EPSRC and STFC PhD Scholarship – Fully Funded
Closing date: 14 March 2021
Key Information
This scholarship is funded by the Engineering and Physical Sciences Research Council (EPSRC) and Science and Technology Facilities Council (STFC).
Start date: October 2021
Supervisors:
- Supervisor 1: Professor Prem Kumar (Physics)
- Supervisor 2: Professosr Biagio Lucini (Maths)
- Supervisor 3: Professor Tim Hollowood (Physics) & Dr Dan Thompson (Physics)
Project description:
This theoretical project will develop novel, rigorous techniques, to calculate refined measures of quantum entanglement of spatial regions in conformal field theories with boundaries (BCFTs) at large central charge, in thermal and “locally quenched” non-thermal initial states.
At large central charge, BCFT correlators that compute measures of quantum information are expected to undergo a sharp transition (as a function of the size of spatial regions). This is due to a switch in dominance between intermediate exchanges involving bulk primary states to intermediate exchanges of boundary states.
A major goal will be to make precise this qualitative picture within the framework of “generalized free fields” which have recently been proposed as the appropriate CFT construct to describe strongly coupled CFTs possessing holographic gravity duals. Little is known about interacting BCFT n-point functions. Our investigation will reveal new general features of BCFT entanglement measures at strong coupling.
A deep physical interpretation of the BCFT system has in recent months been at the epicentre of one of the most important advances in theoretical physics made in recent times (Nov 2019):
Holographic duality relates a BCFT to the same CFT propagating in the near horizon geometry of a black hole dual to the boundary degrees of freedom. Thus BCFT measures of entanglement get related to quantum entanglement entropies of subsets of Hawking radiation emitted by the black hole!
The transition between the two regimes of BCFT correlators is precisely what resolves the celebrated information loss paradox for black holes posed by Hawking. In the gravity picture the transition is between the usual black hole geometry and a new semiclassical wormhole saddle-point.
Remarkably, the wormhole geometry identifies the black hole interior with the Hawking radiation outside and reproduces the celebrated “Page curve” for the entanglement entropy of Hawking radiation required by unitarity of Quantum Mechanics.
Our goal is to understand how the black hole interior degrees of freedom are encoded in the Hawking radiation. We can extract this from strongly coupled bCFT correlators modelled by generalised free fields. We will also compare and contrast these fine-grained correlations against our previous results for weakly coupled CFTs propagating in the black hole background.
The question raised above is perhaps the single most pressing one in the effort to pick apart the complexity of the quantum state of the Hawking radiation emitted by a black hole and how universal its detailed properties are.
The inclusion of wormhole saddles in the gravitational partition function, instrumental in resolving the information loss paradox, leads to a beautiful interpretation of the gravitational description of the system: it is a sum of partition functions of the so-called 2d JT gravity defined over surfaces of arbitrary genus and arbitrary number of boundaries. Remarkably these correspond to the genus expansion of certain matrix integrals. It remains a fascinating question to understand how such a genus expansion is encoded in BCFT correlators, one which we expect to be able to attack in the final stages of the project.
The questions we plan to address are topical and yet largely unexplored. The Swansea team consists of world leading experts (TJH, DT, SPK ) in holography, string theory and QFT (BL) and has already produced publications in closely related directions and continues to pursue this research vigorously.
Eligibility
Candidates must have a First, Upper Second Class Honours or a Master’s degree with Merit, in a relevant discipline.
For candidates whose first language is not English, we require IELTS 6.5 (with 6.0 in each component) or equivalent. Please visit our website for a list of acceptable English language tests. We prefer candidates to have already met the English Language requirements at the point of application, although this is not a requirement.
This scholarship is open to UK and international candidates. Please note, international and EU students may have to pay the difference between the home (UK) UKRI fee and the institutional international student fee.
NB: If you are holding a non-UK degree, please see Swansea University degree comparisons to find out if you meet the eligibility.
If you have any questions regarding your academic eligibility based on the above comparison, please email pgrscholarships@swansea.ac.uk with the web-link to the scholarship(s) you are interested in.
Funding
This three-year fully funded scholarship covers UK tuition fees and an annual stipend of £15,285.
Research Training Support Grant (RTSG) of £1,000 per annum covering travel and other research expenses is also provided.
This scholarship is open to UK and international candidates. Please note, international and EU students may have to pay the difference between the home (UK) UKRI fee and the institutional international student fee.
How to Apply
To apply, please complete and submit the following documents to science-scholarships@swansea.ac.uk:
- College of Science PGR Scholarship Application
- Equality, Diversity and Inclusion Monitoring Form_Ffurflen Monitro
- Academic References – all scholarship applications require two supporting references to be submitted. Please ensure that your chosen referees are aware of the funding deadline, as their references form a vital part of the evaluation process. Please either include these with your scholarship application or ask your referees to send them directly to science-scholarships@swansea.ac.uk
- Academic Transcripts and Degree Certificates – academic transcripts and degree certificates must be submitted along with the scholarship application by the funding deadline. We will be using these to verify your academic qualifications.
- A recent CV
Candidates should use the ‘Supplementary Personal Statement’ section of the application form to explain why the award they are applying for particularly matches their skills and experience and how they would choose to develop the project.
Please email the documents with ‘EPSRC 34 SCHOLARSHIP 2021-2022’ in the email subject header.
Informal enquiries before the deadline for formal applications are welcome by emailing Professor Prem Kumar (S.P.Kumar@Swansea.ac.uk).