Bianchi identities in f(T) gravity: Paving the way to confrontation with astrophysics

Golovnev, Alexey; Guzmán, María-José

doi:10.1016/j.physletb.2020.135806

Cited by 38 publications

(60 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similarly to the fact that f (T ) gravity is not equivalent to f (R) gravity, the torsion tensor with or without the spin connection leads to a different theory. In other words, the spin connection ω µ which ensures the covariance of the theory will appear in the field equations [18,72,82,83].…”

Section: F (T ) Gravitymentioning

confidence: 99%

Deflection angle and lensing signature of covariant f(T) gravity

Ren,

Zhao,

Saridakis

et al. 2021

Preprint

View full text Add to dashboard Cite

We calculate the deflection angle, as well as the positions and magnifications of the lensed images, in the case of covariant f (T ) gravity. We first extract the spherically symmetric solutions for both the pure-tetrad and the covariant formulation of the theory, since considering spherical solutions the extension to the latter is crucial, in order for the results not to suffer from frame-dependent artifacts. Applying the weak-field, perturbative approximation we extract the deviations of the solutions comparing to General Relativity. Furthermore, we calculate the deflection angle and then the differences of the positions and magnifications in the lensing framework. This effect of consistent f (T ) gravity on the lensing features can serve as an observable signature in the realistic cases where f (T ) is expected to deviate only slightly from General Relativity, since lensing scales in general are not restricted as in the case of Solar System data, and therefore deviations from General Relativity could be observed more easily.

show abstract

Section: F (T ) Gravitymentioning

confidence: 99%

Deflection angle and lensing signature of covariant f(T) gravity

Ren,

Zhao,

Saridakis

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…The study of static spherically symmetric solutions in f (T)-gravity, and its f (T, B) and f (T ax , T vec , T ten ) generalizations [35,36], is an ongoing field of research [37,38].…”

Section: Introductionmentioning

confidence: 99%

Static Spherically Symmetric Black Holes in Weak f(T)-Gravity

Pfeifer

Schuster

2021

Universe

View full text Add to dashboard Cite

With the advent of gravitational wave astronomy and first pictures of the “shadow” of the central black hole of our milky way, theoretical analyses of black holes (and compact objects mimicking them sufficiently closely) have become more important than ever. The near future promises more and more detailed information about the observable black holes and black hole candidates. This information could lead to important advances on constraints on or evidence for modifications of general relativity. More precisely, we are studying the influence of weak teleparallel perturbations on general relativistic vacuum spacetime geometries in spherical symmetry. We find the most general family of spherically symmetric, static vacuum solutions of the theory, which are candidates for describing teleparallel black holes which emerge as perturbations to the Schwarzschild black hole. We compare our findings to results on black hole or static, spherically symmetric solutions in teleparallel gravity discussed in the literature, by comparing the predictions for classical observables such as the photon sphere, the perihelion shift, the light deflection, and the Shapiro delay. On the basis of these observables, we demonstrate that among the solutions we found, there exist spacetime geometries that lead to much weaker bounds on teleparallel gravity than those found earlier. Finally, we move on to a discussion of how the teleparallel perturbations influence the Hawking evaporation in these spacetimes.

show abstract

“…In this way, one set of the elements of the kernel can be taken as v |g|e a = e 0 e δ a g , with the index |g| used as labelling for the elements. Applying it to the Hessian gives straightforwardly v |g|e a C ab ef = 0, and therefore the trivial primary constraints (10) are found. In order to find the Lorentz constraints, we consider the elements of the kernel whose coefficients are v |gh|e a = 2δ a [g η h]e (where the indices |gh| are labelling six elements of the kernel), which accomplish…”

Section: Pure Tetrad Tegr and Its Primary Constraintsmentioning

confidence: 99%

“…Construction of cosmological solutions in f (T) gravity and analysis of cosmological perturbations therein are relatively successful [7,8] since the number of dynamical degrees of freedom at the linear level is the same as in GR [9]. An essential feature appearing at this level is a non-vanishing gravitational slip, which seems to be a generic feature of modified teleparallel models, and might help to test these models with future observations, together with confrontation with astrophysics [10].…”

Section: Introductionmentioning

confidence: 99%

Lorentz symmetries and primary constraints in covariant teleparallel gravity

Golovnev,

Guzman

2021

Preprint

Self Cite

View full text Add to dashboard Cite

In this article we explore local Lorentz transformations in theories of gravity based on the teleparallel formalism. For the teleparallel equivalent of general relativity (TEGR), the spin connection plays no role in the equations of motion, and therefore it is possible to simply put it equal to zero with no change in physical quantities, and then the theory is formulated purely in terms of the tetrad field which can be freely chosen in any way. In nonlinear modifications of TEGR, this is a more intricate issue, and vanishing spin connection is then the Weitzenböck gauge choice which imposes restrictions on the choice of tetrad. This has led to considering the so-called covariant formulation of f (T ) gravity. We examine the primary constraints arising when passing to the Hamiltonian framework, and compute their algebra. We show that the problems of local Lorentz symmetry breaking still appear in this formulation, even if in a different disguise.

show abstract

Bianchi identities in f(T) gravity: Paving the way to confrontation with astrophysics

Cited by 38 publications

References 29 publications

Deflection angle and lensing signature of covariant f(T) gravity

Deflection angle and lensing signature of covariant f(T) gravity

Static Spherically Symmetric Black Holes in Weak f(T)-Gravity

Lorentz symmetries and primary constraints in covariant teleparallel gravity

Contact Info

Product

Resources

About