Fundamental fields, General Relativity and black holes
Lead Research Organisation:
University of Sheffield
Department Name: Mathematics and Statistics
Abstract
In the first year, the project concerns the scattering, absorption and emission of an electromagnetic field by a rotating (Kerr) black hole. The student will use the Debye/Hertz potential approach of Cohen & Kegeles (1974), to reconstruct the Faraday tensor on a Kerr black hole background by acting on a single complex scalar quantity with differential operators. The complex scalar is governed by a second-order PDE that is separable. By constructing a sum over the modes, the student will examine aspects such as planar wave scattering (via scattering cross sections); quasi-normal modes and Regge pole spectra; and electromagnetic self-force.
People |
ORCID iD |
| Sam Dolan (Primary Supervisor) | |
| Thomas Stratton (Student) |
Publications
Dolan S
(2017)
Rainbow scattering in the gravitational field of a compact object
in Physical Review D
Macedo C
(2018)
Spectral lines of extreme compact objects
in Physical Review D
Stratton T
(2019)
Rainbow scattering of gravitational plane waves by a compact body
in Physical Review D
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509735/1 | 01/10/2016 | 30/09/2021 | |||
| 1798678 | Studentship | EP/N509735/1 | 01/10/2016 | 31/03/2020 | Thomas Stratton |
| Description | We have developed the theory of scattering by compact bodies. More specifically, we have examined scattering of waves by compact stars, such as a neutron star. The waves correspond to perturbations (disturbances) of the gravitational field (gravitational waves) or the electromagnetic field (light). We have discovered that one might expect to see a diffraction phenomenan in scattering by compact bodies, known as rainbow scattering. This is analogous to the everday atmospheric effect. There is an intense `bow' and chromatic seperation (of frequencies). There are additional effects associated with the helicity or spin of the field. Scattering by black holes has been studied extensively and we have compared and constrasted with these results. We have developed compex angular momentum techniques used in classical and nuclear scattering studies. Also, in collaborations we have investigated scattering and absorption by so called black hole `mimickers'. This is part of the ongoing effort to distinguish black holes from possible alternatives. |
| Exploitation Route | We think our findings could be tested by analogue systems such as bathtub experiments. For example, there is the group at Nottingham University led by Dr Silke Weinfurtner who construct black hole analogue experiments (https://www.gravitylaboratory.com/) who we have had discussions with. This could be relatively easy to implement and possibly take to a wider audience including school children. It would be an inspiring sight for budding scientists to "see" gravitational waves scattered by a neutron star. |
| Sectors | Education |
| URL | https://journals.aps.org/prd/abstract/10.1103/PhysRevD.95.124055 |
| Description | University of Sheffield and Federal University of Para |
| Organisation | Federal University of Pará |
| Country | Brazil |
| Sector | Academic/University |
| PI Contribution | Myself and Dr Sam Dolan participated in a collaboration with two researchers from the Federal University of Pará (UFPA). We contributed to a project researching the absorptive properties of exotic compact objects. This resulted in the output of a paper together entitled: "Spectral lines of extreme compact objects" We are still working on some research into scattering by compact bodies with researchers at UFPA. |
| Collaborator Contribution | Our partners led the research project into scattering and absorption by exotic compact objects, partly inspired by our previous work. |
| Impact | Article in Physical Review D DOI: https://doi.org/10.1103/PhysRevD.98.104034 |
| Start Year | 2018 |