Problems with Propagation and Time Evolution in f(T) Gravity

Abstract

Teleparallel theories of gravity have a long history. They include a special case referred to as the Teleparallel Equivalent of General Relativity (TEGR, aka GR${}_{\Vert }$). Recently this theory has been generalized to f(T) gravity. Tight constraints from observations suggest that f(T) gravity is not as robust as initially hoped. This might hint at hitherto undiscovered problems at the theoretical level. In this work, we point out that a generic f(T) theory can be expected to have certain problems including superluminal propagating modes, the presence of which can be revealed by using the characteristic equations that govern the dynamics in f(T) gravity and/or the Hamiltonian structure of the theory via Dirac constraint analysis. We use several examples from simpler gauge field theories to explain how such superluminal modes could arise. We also point out problems with the Cauchy development of a constant time hypersurface in FLRW spacetime in f(T) gravity. The time evolution from a FLRW (and as a special case, Minkowski spacetime) initial condition is not unique.

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References in corpus (15)

• Resummation of Massive Gravity
• Dark torsion as the cosmic speed-up
• Einstein's Other Gravity and the Acceleration of the Universe
• Generalizations of teleparallel gravity and local Lorentz symmetry
• Solar system constraints on f(T) gravity
• Massive gravity: nonlinear instability of the homogeneous and isotropic universe
• Cuscuton: A Causal Field Theory with an Infinite Speed of Sound
• Degrees of freedom of $f(T)$ gravity
• On causality and superluminal behavior in classical field theories. Applications to k-essence theories and MOND-like theories of gravity
• Acausality of Massive Gravity
• Cosmological Perturbation in f(T) Gravity Revisited
• Anisotropic Friedmann-Robertson-Walker universe from nonlinear massive gravity
• 6+1 lessons from f(R) gravity
• Post-Newtonian Generation of Gravitational Waves in a Theory of Gravity with Torsion
• Spherically symmetric analysis on open FLRW solution in non-linear massive gravity

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