Spherically symmetric vacuum solutions in one-parameter new general relativity and their phenomenology

authored by: Helen Asuküla, Manuel Hohmann, Vasiliki Karanasou, Sebastian Bahamonde, Christian Pfeifer, João Luís Rosa
Abstract: In this work, we study spherically symmetric vacuum solutions in one-parameter new general relativity (NGR), a specific theory in teleparallel gravity which is constructed from the three possible quadratic scalars obtained from torsion with arbitrary coefficients satisfying the requirements for the absence of ghosts. In this class of modified theories of gravity, the observable effects of gravity result from the torsion rather than the curvature of the spacetime. Unlike in GR, where the fundamental quantity is the metric from which the Levi-Civita connection is derived, in teleparallel theories of gravity the fundamental variable is the tetrad, from which one constructs the metric and the teleparallel connection. We consider the most general tetrad for spherical symmetry and we derive the corresponding field equations. Under adequate assumptions, we find three different branches of vacuum solutions and discuss their associated phenomenology. In particular, we analyze the photon sphere, the classical tests of GR such as the light deflection, the Shapiro delay, and the perihelion shift, and also the Komar mass, while providing a detailed comparison with their Schwarzschild spacetime counterparts. Finally, we analyze how the observational imprints from accretion disks and shadows are affected in comparison with their GR counterparts, and conclude that the free parameters of the model might induce additional attractive or repulsive effects to the propagation of photons, depending on their values.
External Organisation(s): University of Tartu
University of Tokyo
University of Gdansk
Center of Applied Space Technology and Microgravity (ZARM)
Type: Article
Journal: Physical Review D
Volume: 109
ISSN: 2470-0010
Publication date: 11.03.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Nuclear and High Energy Physics
Electronic version(s): https://doi.org/10.1103/PhysRevD.109.064027 (Access: Unknown)

BibTeX

@article{02a22e71ecc44a28acb02d07f088c19d,
title = "Spherically symmetric vacuum solutions in one-parameter new general relativity and their phenomenology",
abstract = "In this work, we study spherically symmetric vacuum solutions in one-parameter new general relativity (NGR), a specific theory in teleparallel gravity which is constructed from the three possible quadratic scalars obtained from torsion with arbitrary coefficients satisfying the requirements for the absence of ghosts. In this class of modified theories of gravity, the observable effects of gravity result from the torsion rather than the curvature of the spacetime. Unlike in GR, where the fundamental quantity is the metric from which the Levi-Civita connection is derived, in teleparallel theories of gravity the fundamental variable is the tetrad, from which one constructs the metric and the teleparallel connection. We consider the most general tetrad for spherical symmetry and we derive the corresponding field equations. Under adequate assumptions, we find three different branches of vacuum solutions and discuss their associated phenomenology. In particular, we analyze the photon sphere, the classical tests of GR such as the light deflection, the Shapiro delay, and the perihelion shift, and also the Komar mass, while providing a detailed comparison with their Schwarzschild spacetime counterparts. Finally, we analyze how the observational imprints from accretion disks and shadows are affected in comparison with their GR counterparts, and conclude that the free parameters of the model might induce additional attractive or repulsive effects to the propagation of photons, depending on their values.",
author = "Helen Asuk{\"u}la and Manuel Hohmann and Vasiliki Karanasou and Sebastian Bahamonde and Christian Pfeifer and Rosa, {Jo{\~a}o Lu{\'i}s}",
note = "Publisher Copyright: {\textcopyright} 2024 American Physical Society.",
year = "2024",
month = mar,
day = "11",
doi = "10.1103/PhysRevD.109.064027",
language = "English",
volume = "109",
journal = "Physical Review D",
issn = "2470-0010",
publisher = "American Institute of Physics",
number = "6",
}