Dispersive photon propagation in semiclassical higher-derivative gravity

2015 ◽  
Vol 30 (11) ◽  
pp. 1550052 ◽  
Author(s):  
Antonio Accioly ◽  
José Helayël-Neto ◽  
F. E. Barone ◽  
Breno Giacchini ◽  
Wallace Herdy
Keyword(s):  
Gravitational Field ◽  
Coordinate System ◽  
Upper Bound ◽  
Massive Particle ◽  
Visible Spectrum ◽  
The Sun ◽  
Photon Propagation ◽  
External Gravitational Field ◽  
Higher Derivative ◽  
Gravity Equations

The scattering of a photon by a weak external gravitational field which is solution of the linearized higher-derivative gravity equations sourced by a point-like massive particle located at the origin of the coordinate system, is analyzed. It is shown that the [Formula: see text]-sector of the theory produces dispersive photon propagation. Subsequently, the angle |Δθ|(≡|θ violet -θ red |) at which the visible spectrum would be spread over in the case of a photon passing by the Sun is plotted as a function of the |β|-constant related to the [Formula: see text]-sector. An upper bound on |β| is then found. Interestingly enough, this limit is thirteen orders of magnitude below the accepted upper bound on |β|.

scholarly journals Gravitational field of scalar lumps in higher-derivative gravity

2021 ◽  
Vol 103 (12) ◽  
Author(s):  
Luca Buoninfante ◽  
Yuichi Miyashita
Keyword(s):  
Gravitational Field ◽  
Higher Derivative

The spin-zero Duffin-Kemmer-Petiau equation in a cosmic-string space-time with the Cornell interaction

2016 ◽  
Vol 31 (36) ◽  
pp. 1650191 ◽  
Author(s):  
M. de Montigny ◽  
M. Hosseinpour ◽  
H. Hassanabadi
Keyword(s):  
Gravitational Field ◽  
Coordinate System ◽  
Cosmic String ◽  
Topological Defects ◽  
Space Time ◽  
Dkp Equation

In this paper, we study the covariant Duffin-Kemmer-Petiau (DKP) equation in the cosmic-string space-time and consider the interaction of a DKP field with the gravitational field produced by topological defects in order to examine the influence of topology on this system. We solve the spin-zero DKP oscillator in the presence of the Cornell interaction with a rotating coordinate system in an exact analytical manner for nodeless and one-node states by proposing a proper ansatz solution.

scholarly journals Modeling the center-to-limb variation of the Ca i 4227 Å line using FCHHT models

2014 ◽  
Vol 10 (S305) ◽  
pp. 381-386
Author(s):  
H. D. Supriya ◽  
H. N. Smitha ◽  
K. N. Nagendra ◽  
J. O. Stenflo ◽  
M. Bianda ◽  
...  
Keyword(s):  
Solar Spectrum ◽  
Visible Spectrum ◽  
Observational Constraints ◽  
Solar Model ◽  
The Sun ◽  
Dimensional Modeling ◽  
Height Dependence ◽  
Computationally Expensive ◽  
Chromospheric Line ◽  
The Magnetic Field

AbstractThe Ca i 4227 Å is a chromospheric line exhibiting the largest degree of linear polarization near the limb, in the visible spectrum of the Sun. Modeling the observations of the center-to-limb variations (CLV) of different lines in the Second Solar Spectrum helps to sample the height dependence of the magnetic field, as the observations made at different lines of sight sample different heights in the solar atmosphere. Supriya et al. (2014) attempted to simultaneously model the CLV of the (I, Q/I) spectra of the Ca i 4227 Å line using the standard 1-D FAL model atmospheres. They found that the standard FAL model atmospheres and also any appropriate combination of them, fail to simultaneously fit the observed Stokes (I, Q/I) profiles at all the limb distances (μ) satisfying at the same time all the observational constraints. This failure of 1-D modeling approach can probably be overcome by using multi-dimensional modeling which is computationally expensive. To eliminate an even wider choice of 1-D models, we attempt here to simultaneously model the CLV of the (I, Q/I) spectra using the FCHHT solar model atmospheres which are updated and recent versions of the FAL models. The details of our modeling efforts and the results are presented.

scholarly journals Gravity-Based Characterization of Three-Axis Accelerometers in Terms of Intrinsic Accelerometer Parameters

2017 ◽  
Vol 122 ◽  
Author(s):  
Jon Geist ◽  
Muhammad Yaqub Afridi ◽  
Craig D. McGray ◽  
Michael Gaitan
Keyword(s):  
Gravitational Field ◽  
Coordinate System ◽  
Measurement Errors ◽  
Angle Measurement ◽  
Sensitivity Matrix ◽  
Cross Sensitivity ◽  
Measurement Capability ◽  
Intrinsic Parameters ◽  
The Cross ◽  
Alignment Errors

Cross-sensitivity matrices are used to translate the response of three-axis accelerometers into components of acceleration along the axes of a specified coordinate system. For inertial three-axis accelerometers, this coordinate system is often defined by the axes of a gimbal-based instrument that exposes the device to different acceleration inputs as the gimbal is rotated in the local gravitational field. Therefore, the cross-sensitivity matrix for a given three-axis accelerometer is not unique. Instead, it depends upon the orientation of the device when mounted on the gimbal. We define nine intrinsic parameters of three-axis accelerometers and describe how to measure them directly and how to calculate them from independently determined cross-sensitivity matrices. We propose that comparisons of the intrinsic parameters of three axis accelerometers that were calculated from independently determined cross-sensitivity matrices can be useful for comparisons of the cross-sensitivity-matrix measurement capability of different institutions because the intrinsic parameters will separate the accelerator-gimbal alignment differences among the participating institutions from the purely gimbal-related differences, such as gimbal-axis orthogonality errors, z-axis gravitational-field alignment errors, and angle-setting or angle-measurement errors.

scholarly journals ISSUE ON MEASURING THE LIGHT SPEED IN VACUUM

2021 ◽  
Vol 82 (4) ◽  
pp. 61-64
Author(s):  
Vasil Сhaban ◽  
Keyword(s):  
Gravitational Field ◽  
Differential Equations ◽  
Gravitational Lens ◽  
Electric Signal ◽  
The Sun ◽  
Speed Of Light ◽  
Light Speed ◽  
Shapiro Effect

Based on the proposed differential equations of the interaction of the electric signal with the gravitational field, the observed phenomena are known as the gravitational lens and the Shapiro effect are investigated. The deflection of a light ray in the field of the Sun is simulated. It is shown that a moving photon undergoes in the gravitational field not only a transverse action, which causes a curvature of the trajectory but also a longitudinal one, implementing the acceleration-braking processes. As a result, the instability of the speed of light in a vacuum was revealed.

scholarly journals Approximate Inertial Coordinate System Selections for Rotation Problems - The Gravitational Field of the Celestial Body Higher than the Object Being Rotated

2015 ◽  
Vol 8 (1) ◽  
pp. 102
Author(s):  
Zifeng Li
Keyword(s):  
Gravitational Field ◽  
Coordinate System ◽  
Celestial Body ◽  
Angular Speed ◽  
Calculation Error ◽  
Cartesian Coordinate System ◽  
Inertial Coordinate System ◽  
The Earth ◽  
The Galaxy ◽  
Cartesian Coordinate

<p class="1Body">Selection of the coordinate system is essential for rotation problems. Otherwise, mistakes may occur due to inaccurate measurement of angular speed. Approximate inertial coordinate system selections for rotation problems should be the gravitational field of the celestial body higher than the object being rotated: (1) the Earth fixed Cartesian coordinate system for normal rotation problem; (2) heliocentric - geocentric Cartesian coordinate system for satellites orbiting the Earth; (3) the Galaxy Heart - heliocentric Cartesian coordinates for Earth's rotation around the Sun. In astrophysics, mass calculation error and angular velocity measurement error lead to a black hole conjecture.</p>

scholarly journals Geodesic Effect Near an Elliptical Orbit

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Alina-Daniela Vîlcu
Keyword(s):  
Gravitational Field ◽  
Elliptical Orbit ◽  
Newtonian Mechanics ◽  
The Sun ◽  
Classical Approach ◽  
De Sitter ◽  
Lagrange Equations ◽  
The Earth ◽  
Elliptical Motion

Using a differential geometric treatment, we analytically derived the expression for De Sitter (geodesic) precession in the elliptical motion of the Earth through the gravitational field of the Sun with Schwarzschild's metric. The expression obtained in this paper in a simple way, using a classical approach, agrees with that given in B. M. Barker and R. F. O'Connell (1970, 1975) in a different setting, using the tools of Newtonian mechanics and the Euler-Lagrange equations.

Sign in / Sign up

Export Citation Format

Share Document