2019/10/03 by Rhiannon Cuttell, Cuttell, Rhiannon
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th) #Noncommutative and Quantum Gravity Theories #gr-qc #hep-th
paper · pdf · doi:10.48550/arxiv.1910.01699
Ph.D. thesis, King's College London. Submission date: Nov 2018. Award date: Apr 2019. EThOS ID: uk.bl.ethos.784497. 128 pages, 10 figures. Text overlap with arxiv:1409.1902, arxiv:1806.06791, arXiv:1812.07530, and arxiv:1901.07383
arxiv created 2019/10/03 · openalex publication_date 2019/10/03 · arxiv updated 2019/10/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this thesis, I investigate how to construct a self-consistent model of deformed general relativity using canonical methods and metric variables. The specific deformation of general covariance is predicted by some studies into loop quantum cosmology. I firstly find the minimally-deformed model for a scalar-tensor theory, thereby establishing a classical reference point, and investigate the cosmological effects of a non-minimal coupled scalar field. By treating the deformation perturbatively, I derive the deformed gravitational action which includes the nearest order of curvature corrections. Then working more generally, I derive the deformed scalar-tensor constraint to all orders and I find that the momenta and spatial derivatives from gravity and matter must combine in a very specific form. It suggests that the deformation should be equally affected by matter field derivatives as it is by gravitational curvature. Finally, I derive the deformed gravitational action to all orders, and find how intrinsic and extrinsic curvatures differently affect the deformation. The deformation seems to be required to satisfy a non-linear equation usually found in fluid mechanics.