scholarly journals Weak field limit and gravitational waves in f(T, B) teleparallel gravity

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
Salvatore Capozziello ◽  
Maurizio Capriolo ◽  
Loredana Caso
Keyword(s):  
Gravitational Waves ◽  
Teleparallel Gravity ◽  
Weak Field ◽  
Massive Scalar ◽  
Tensor Polarization ◽  
Field Equations ◽  
Field Limit ◽  
Weak Field Limit ◽  
Limit Approximation ◽  
Scalar Mode

Abstract We derive the gravitational waves for $$f\left( T, B\right) $$fT,B gravity which is an extension of teleparallel gravity and demonstrate that it is equivalent to f(R) gravity by linearized the field equations in the weak field limit approximation. f(T, B) gravity shows three polarizations: the two standard of general relativity, plus and cross, which are purely transverse with two-helicity, massless tensor polarization modes, and an additional massive scalar mode with zero-helicity. The last one is a mix of longitudinal and transverse breathing scalar polarization modes. The boundary term B excites the extra scalar polarization and the mass of scalar field breaks the symmetry of the TT gauge by adding a new degree of freedom, namely a single mixed scalar polarization.

scholarly journals Gravitoelectromagnetism, Solar System Tests, and Weak-Field Solutions in f (T,B) Gravity with Observational Constraints

Universe ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 34 ◽  
Author(s):  
Gabriel Farrugia ◽  
Jackson Levi Said ◽  
Andrew Finch
Keyword(s):  
Solar System ◽  
Teleparallel Gravity ◽  
Weak Field ◽  
Observational Constraints ◽  
Field Limit ◽  
Potential Models ◽  
Weak Field Limit ◽  
Rotating Systems ◽  
Theories Of Gravity ◽  
Analogous Effect

Gravitomagnetism characterizes phenomena in the weak-field limit within the context of rotating systems. These are mainly manifested in the geodetic and Lense-Thirring effects. The geodetic effect describes the precession of the spin of a gyroscope in orbit about a massive static central object, while the Lense-Thirring effect expresses the analogous effect for the precession of the orbit about a rotating source. In this work, we explore these effects in the framework of Teleparallel Gravity and investigate how these effects may impact recent and future missions. We find that teleparallel theories of gravity may have an important impact on these effects which may constrain potential models within these theories.

scholarly journals Metric-affine bumblebee gravity: classical aspects

2021 ◽  
Vol 81 (4) ◽  
Author(s):  
Adrià Delhom ◽  
J. R. Nascimento ◽  
Gonzalo J. Olmo ◽  
A. Yu. Petrov ◽  
Paulo J. Porfírio
Keyword(s):  
Physical Properties ◽  
Weak Field ◽  
The Other ◽  
Effective Theory ◽  
Field Equations ◽  
Field Limit ◽  
Weak Field Limit ◽  
Effective Metric ◽  
The Stability ◽  
Matter Fields

AbstractWe consider the metric-affine formulation of bumblebee gravity, derive the field equations, and show that the connection can be written as Levi-Civita of a disformally related metric in which the bumblebee field determines the disformal part. As a consequence, the bumblebee field gets coupled to all the other matter fields present in the theory, potentially leading to nontrivial phenomenological effects. To explore this issue we compute the post-Minkowskian, weak-field limit and study the resulting effective theory. In this scenario, we couple scalar and spinorial matter to the effective metric, and then we explore the physical properties of the VEV of the bumblebee field, focusing mainly on the dispersion relations and the stability of the resulting effective theory.

scholarly journals Weak Deflection Angle by Casimir Wormhole Using Gauss-Bonnet Theorem and Its Shadow

2020 ◽  
Author(s):  
Wajiha Javed ◽  
Ali Hamza ◽  
Ali Övgün
Keyword(s):  
Deflection Angle ◽  
Weak Field ◽  
Plasma Medium ◽  
Field Limit ◽  
Spacetime Geometry ◽  
Weak Field Limit ◽  
The Deflection Angle ◽  
Bonnet Theorem ◽  
Limit Approximation ◽  
Optical Metric

In this paper, we calculate the deflection angle of photon by Casimir wormhole in the weak field limit approximation. First we calculate Gaussian optical curvature with the help of optical spacetime geometry and so we use the Gauss-Bonnet theorem on the Gaussian optical metric. Then we find the deflection angle of photon by Casimir wormhole. Moreover, we calculate the photon's deflection angle in the presence of plasma medium and we also see the graphical nature of deflection angle in both cases. Second, we move towards the shadow of Casimir wormhole. After the observations of Event Horizon Telescope, the study of shadow become very important so that we plot the shapes of shadow of Casimir wormhole, and we calculate the photon geodesic around the Casimir wormhole.

Gravity as a gauge theory

2018 ◽  
Author(s):  
Michael Kachelriess
Keyword(s):  
Gauge Theory ◽  
Weak Field ◽  
Einstein Equations ◽  
Field Equations ◽  
Field Limit ◽  
Weak Field Limit ◽  
Standard Formalism

The vielbein formalism is developed as a tool to determine the coupling of matter to gravity. After determining the relation to the standard formalism, the action and the field equations of gravity are introduced. The linearised Einstein equations which describe the weak-field limit of gravity are derived.

scholarly journals Weak field limit and gravitational waves in higher-order gravity

2019 ◽  
Vol 16 (03) ◽  
pp. 1950047 ◽  
Author(s):  
Salvatore Capozziello ◽  
Maurizio Capriolo ◽  
Loredana Caso
Keyword(s):  
Gravitational Waves ◽  
Order Term ◽  
Normal Modes ◽  
Weak Field ◽  
Higher Order ◽  
Field Limit ◽  
Weak Field Limit ◽  
Higher Order Gravity ◽  
Higher Order Derivative ◽  
Effective Theories

We derive the weak field limit for a gravitational Lagrangian density [Formula: see text], where higher-order derivative terms in the Ricci scalar [Formula: see text] are taken into account. The interest for this kind of effective theories comes out from the consideration of the infrared and ultraviolet behaviors of gravitational field and, in general, from the formulation of quantum field theory in curved spacetimes. Here, we obtain solutions in weak field regime both in vacuum and in the presence of matter and derive gravitational waves considering the contribution of [Formula: see text] terms. By using a suitable set of coefficients [Formula: see text], it is possible to find up to [Formula: see text] normal modes of oscillation with six polarization states with helicity 0 or 2. Here [Formula: see text] is the higher-order term in the [Formula: see text] operator appearing in the gravitational Lagrangian. More specifically: the mode [Formula: see text], with [Formula: see text], has transverse polarizations [Formula: see text] and [Formula: see text] with helicity 2; the [Formula: see text] modes [Formula: see text], with [Formula: see text], have transverse polarizations [Formula: see text] and non-transverse ones [Formula: see text], [Formula: see text], [Formula: see text] with helicity 0.

GALACTIC AND ASTROPHYSICAL SIZES FROM SCALAR-TENSOR THEORY OF GRAVITY

2004 ◽  
Vol 13 (02) ◽  
pp. 359-371 ◽  
Author(s):  
GIUSEPPE BASINI ◽  
MARCO RICCI ◽  
FULVIO BONGIORNO ◽  
SALVATORE CAPOZZIELLO
Keyword(s):  
Scalar Field ◽  
Spiral Galaxies ◽  
Weak Field ◽  
Newtonian Potential ◽  
Scalar Tensor Theory ◽  
Field Limit ◽  
Weak Field Limit ◽  
Tensor Theory ◽  
Flat Rotation Curves ◽  
Theory Of Gravity

We investigate the weak-field limit of scalar-tensor theory of gravity and show that results are directly depending on the coupling and self-interaction potential of the scalar field. In particular, corrections are derived for the Newtonian potential. We discuss astrophysical applications of the results, in particular the flat rotation curves of spiral galaxies.

scholarly journals Quantum Faraday Effect in the Universe

2017 ◽  
Vol 45 ◽  
pp. 1760046
Author(s):  
Lídice Cruz Rodríguez ◽  
Aurora Pérez Martínez ◽  
Gabriella Piccinelli ◽  
Elizabeth Rodríguez Querts
Keyword(s):  
Faraday Effect ◽  
Weak Field ◽  
Field Limit ◽  
Self Energy ◽  
Weak Field Limit ◽  
Resonant Behavior ◽  
Degenerate Regime ◽  
The Universe ◽  
Resonant Mechanism ◽  
Recombination Epoch

We study the Quantum Faraday rotation starting from the photon self-energy in the presence of a constant magnetic field. The Faraday angle is calculated in the non-degenerate regime and for weak field limit. Two physical scenarios, possibly characterized by these conditions, are the recombination epoch and the jets originated in pulsars. We discuss the resonant behavior that the Faraday angle exhibits in these scenarios and investigate the possibility of detecting cosmic magnetic fields through this resonant mechanism.

Weak-field limit

2010 ◽  
pp. 165-208
Author(s):  
Salvatore Capozziello ◽  
Valerio Faraoni
Keyword(s):  
Weak Field ◽  
Field Limit ◽  
Weak Field Limit
Sign in / Sign up

Export Citation Format

Share Document