A Cosmological unicorn solution to Finsler gravity

authored by: Sjors Heefer, Christian Pfeifer, Antonio Reggio, Andrea Fuster
Abstract: We present a new family of exact vacuum solutions to Pfeifer and Wohlfarth's field equation in Finsler gravity, consisting of Finsler metrics that are Landsbergian but not Berwaldian, also known as unicorns due to their rarity. Interestingly, we find that these solutions have a physically viable light cone structure, even though in some cases the signature is not Lorentzian but positive definite. We furthermore find a promising analogy between our solutions and classical Friedmann-Lemaître-Robertson-Walker cosmology. One of our solutions, in particular, has cosmological symmetry, i.e., it is spatially homogeneous and isotropic, and it is additionally conformally flat, with the conformal factor depending only on the timelike coordinate. We show that this conformal factor can be interpreted as the scale factor, we compute it as a function of cosmological time, and we show that it corresponds to a linearly expanding (or contracting) Finsler universe.
External Organisation(s): Eindhoven University of Technology (TU/e)
University of Bremen
Type: Article
Journal: Physical Review D
Volume: 108
ISSN: 2470-0010
Publication date: 15.09.2023
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Nuclear and High Energy Physics
Electronic version(s): https://doi.org/10.1103/PhysRevD.108.064051 (Access: Unknown)

BibTeX

@article{3ea9466c81554866a13840fcdd239ef5,
title = "A Cosmological unicorn solution to Finsler gravity",
abstract = "We present a new family of exact vacuum solutions to Pfeifer and Wohlfarth's field equation in Finsler gravity, consisting of Finsler metrics that are Landsbergian but not Berwaldian, also known as unicorns due to their rarity. Interestingly, we find that these solutions have a physically viable light cone structure, even though in some cases the signature is not Lorentzian but positive definite. We furthermore find a promising analogy between our solutions and classical Friedmann-Lema{\^i}tre-Robertson-Walker cosmology. One of our solutions, in particular, has cosmological symmetry, i.e., it is spatially homogeneous and isotropic, and it is additionally conformally flat, with the conformal factor depending only on the timelike coordinate. We show that this conformal factor can be interpreted as the scale factor, we compute it as a function of cosmological time, and we show that it corresponds to a linearly expanding (or contracting) Finsler universe.",
author = "Sjors Heefer and Christian Pfeifer and Antonio Reggio and Andrea Fuster",
note = "Funding information: C. P. was funded by the cluster of excellence Quantum Frontiers funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany{\textquoteright}s Excellence Strategy EXC-2123 QuantumFrontiers 390837967. The authors would like to acknowledge networking support by the COST Action CA18108.",
year = "2023",
month = sep,
day = "15",
doi = "10.1103/PhysRevD.108.064051",
language = "English",
volume = "108",
journal = "Physical Review D",
issn = "2470-0010",
publisher = "American Institute of Physics",
number = "6",
}