Testing gravity with cosmology
| Thesis title in Czech: | Testování gravitace pomocí kosmologie |
|---|---|
| Thesis title in English: | Testing gravity with cosmology |
| Key words: | modifikovaná gravitace, kosmologie |
| English key words: | modified gravity, cosmology |
| Academic year of topic announcement: | 2020/2021 |
| Thesis type: | dissertation |
| Thesis language: | angličtina |
| Department: | Institute of Theoretical Physics (32-UTF) |
| Supervisor: | Ignacy Sawicki |
| Author: | hidden - assigned and confirmed by the Study Dept. |
| Date of registration: | 05.10.2020 |
| Date of assignment: | 05.10.2020 |
| Confirmed by Study dept. on: | 05.10.2020 |
| Guidelines |
| This is a project on the interface of theoretical cosmology and observations. The student will focus on finding new observables for theories of modified gravity. In particular the focus would be on understanding how compact objects behave in these theories and how this affects the various predictions for the evolution of close binaries and the production of gravitational waves. The project will then aim to connect such predictions to other constraints coming from cosmology. |
| References |
| [1] hi_class code (http://arxiv.org/abs/arXiv:1909.01828)
[2] Gravitational Wave constants on theories of gravity (http://arxiv.org/abs/arXiv:1710.06394) [3] Consistent observables from modified gravity (http://arxiv.org/abs/arXiv:1404.3713) |
| Preliminary scope of work |
| Around twenty years ago, we discovered that the expansion of the universe, instead of slowing down as one would expect from the fact that gravity is an attractive force, has instead been speeding up. The mechanism which is causing this speed up is called dark energy. One possible explanation for dark energy is a cosmological constant, a fundamental and unchanging property of spacetime. An alternative idea is that this instead is a dynamical mechanism resulting from, for example, a new behaviour of gravity, different than that predicted by Einstein's general relativity at the scales of the size of the universe.
Thinking how to search for any sign of such modifications of gravity has been a core focus of cosmology over the last decade. The next few years will see the newest generation cosmological surveys built with the specific purpose of determining the properties of dark energy come online. Observatories such as the LSST telescope, DESI spectrograph and the Euclid satellite will over the next five to ten years be continuously providing new data. Combining this information with the informational gained from gravitational wave observatories such as LIGO, VIRGO and KAGRA which have been detecting signals since 2016 will allow us to finally determine the nature of dark energy. We seek a PhD student to work with the advisor on the interface of theory and observations. Candidates preferring theoretical work could focus on finding new types of cosmological observables in theories of modified gravity or building our understanding of how compact objects (such as exotic stars and black holes) can behave in these theories. A candidate preferring numerical and data expertise could help develop further the author's hi_class code (link: http://miguelzuma.github.io/hi_class_public/) to implement these new ideas and use it to test gravity using new observational data that will appear during the lifetime of the doctorate. |
| Preliminary scope of work in English |
| Around twenty years ago, we discovered that the expansion of the universe, instead of slowing down as one would expect from the fact that gravity is an attractive force, has instead been speeding up. The mechanism which is causing this speed up is called dark energy. One possible explanation for dark energy is a cosmological constant, a fundamental and unchanging property of spacetime. An alternative idea is that this instead is a dynamical mechanism resulting from, for example, a new behaviour of gravity, different than that predicted by Einstein's general relativity at the scales of the size of the universe.
Thinking how to search for any sign of such modifications of gravity has been a core focus of cosmology over the last decade. The next few years will see the newest generation cosmological surveys built with the specific purpose of determining the properties of dark energy come online. Observatories such as the LSST telescope, DESI spectrograph and the Euclid satellite will over the next five to ten years be continuously providing new data. Combining this information with the informational gained from gravitational wave observatories such as LIGO, VIRGO and KAGRA which have been detecting signals since 2016 will allow us to finally determine the nature of dark energy. We seek a PhD student to work with the advisor on the interface of theory and observations. Candidates preferring theoretical work could focus on finding new types of cosmological observables in theories of modified gravity or building our understanding of how compact objects (such as exotic stars and black holes) can behave in these theories. A candidate preferring numerical and data expertise could help develop further the author's hi_class code (link: http://miguelzuma.github.io/hi_class_public/) to implement these new ideas and use it to test gravity using new observational data that will appear during the lifetime of the doctorate. |