scholarly journals Inductive Rectilinear Frame Dragging and Local Coupling to the Gravitational Field of the Universe

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 284
Author(s):  
L. L. Williams ◽  
Nader Inan
Keyword(s):  
Gravitational Field ◽  
Drag Force ◽  
Rest Frame ◽  
Galaxy Cluster ◽  
Riemann Tensor ◽  
Kerr Metric ◽  
Frame Dragging ◽  
Local Measurements ◽  
The Universe ◽  
Moving Bodies

There is a drag force on objects moving in the background cosmological metric, known from galaxy cluster dynamics. The force is quite small over laboratory timescales, yet it applies in principle to all moving bodies in the universe. The drag force can be understood as inductive rectilinear frame dragging because it also exists in the rest frame of a moving object, and it arises in that frame from the off-diagonal components induced in the boosted-frame metric. Unlike the Kerr metric or other typical frame-dragging geometries, cosmological inductive dragging occurs at uniform velocity, along the direction of motion, and dissipates energy. Proposed gravito-magnetic invariants formed from contractions of the Riemann tensor do not capture inductive dragging effects, and this might be the first identification of inductive rectilinear dragging. The existence of this drag force proves it is possible for matter in motion through a finite region to exchange momentum and energy with the gravitational field of the universe. The cosmological metric can in principle be determined through this force from local measurements on moving bodies, at resolutions similar to that of the Pound–Rebka experiment.

scholarly journals NEUTRINO COUPLING TO COSMOLOGICAL BACKGROUND: A REVIEW ON GRAVITATIONAL BARYO/LEPTOGENESIS

2013 ◽  
Vol 22 (12) ◽  
pp. 1330030 ◽  
Author(s):  
GAETANO LAMBIASE ◽  
SUBHENDRA MOHANTY ◽  
ARAGAM R. PRASANNA
Keyword(s):  
Field Theory ◽  
Gravitational Field ◽  
Thermal Equilibrium ◽  
Energy Levels ◽  
Lepton Number ◽  
Cpt Symmetry ◽  
Cosmological Background ◽  
The Universe ◽  
General Conditions ◽  
Lepton Number Violating

In this paper, we review the theories of origin of matter–antimatter asymmetry in the universe. The general conditions for achieving baryogenesis and leptogenesis in a CPT conserving field theory have been laid down by Sakharov. In this review, we discuss scenarios where a background scalar or gravitational field spontaneously breaks the CPT symmetry and splits the energy levels between particles and antiparticles. Baryon or Lepton number violating processes in proceeding at thermal equilibrium in such backgrounds gives rise to Baryon or Lepton number asymmetry.

A spatially homogeneous gravitational field

1966 ◽  
Vol 62 (1) ◽  
pp. 87-89 ◽  
Author(s):  
V. Joseph
Keyword(s):  
Gravitational Field ◽  
Canonical Form ◽  
Riemann Tensor ◽  
Vacuum Field ◽  
Type I ◽  
Field Equations ◽  
Parameter Group ◽  
Spatially Homogeneous ◽  
Homogeneous Gravitational Field ◽  
Type V

AbstractA solution of Einstein's vacuum field equations, apparently new, is exhibited. The metric, which is homogeneous (that is, admits a three-parameter group of motions transitive on space-like hypersurfaces), belongs to Taub Type V. The canonical form of the Riemann tensor, which is of Petrov Type I, is determined.

scholarly journals Minimum and terminal velocities in projectile motion

2004 ◽  
Vol 26 (2) ◽  
pp. 125-127 ◽  
Author(s):  
E.N. Miranda ◽  
S. Nikolskaya ◽  
R. Riba
Keyword(s):  
Gravitational Field ◽  
Numerical Simulations ◽  
Drag Force ◽  
Initial Velocity ◽  
Terminal Velocity ◽  
Initial Speed ◽  
Projectile Motion ◽  
Minimum Speed ◽  
Minimum Velocity

The motion of a projectile with horizontal initial velocity V0, moving under the action of the gravitational field and a drag force is studied analytically. As it is well known, the projectile reaches a terminal velocity Vterm. There is a curious result concerning the minimum speed Vmin; it turns out that the minimum velocity is lower than the terminal one if V0 > Vterm and is lower than the initial one if V0 < Vterm. These results show that the velocity is not a monotonous function. If the initial speed is not horizontal, there is an angle range where the velocity shows the same behavior mentioned previously. Out of that range, the velocity is a monotonous function. These results comes out from numerical simulations.

scholarly journals Hamiltonian formalism for nonlocal gravity models

2022 ◽  
Author(s):  
Pawan Joshi ◽  
Utkarsh Kumar ◽  
Sukanta Panda
Keyword(s):  
Ricci Tensor ◽  
Degrees Of Freedom ◽  
Hamiltonian Formalism ◽  
Riemann Tensor ◽  
Ricci Scalar ◽  
Gravity Models ◽  
Lagrangian Formalism ◽  
Acceleration Of The Universe ◽  
Nonlocal Action ◽  
The Universe

Nonlocal gravity models are constructed to explain the current acceleration of the universe. These models are inspired by the infrared correction appearing in Einstein–Hilbert action. Here, we develop the Hamiltonian formalism of a nonlocal model by considering only terms to quadratic order in Riemann tensor, Ricci tensor and Ricci scalar. We show how to count degrees of freedom using Hamiltonian formalism including Ricci tensor and Ricci scalar terms. In this model, we have also worked out with a choice of a nonlocal action which has only two degrees of freedom equivalent to GR. Finally, we find the existence of additional constraints in Hamiltonian required to remove the ghosts in our full action. We also compare our results with that of obtained using Lagrangian formalism.

scholarly journals Foundations of a Theory of Gravity with a Constraint and Its Canonical Quantization

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Alexander P. Sobolev
Keyword(s):  
General Relativity ◽  
Gravitational Field ◽  
Early Universe ◽  
Canonical Quantization ◽  
Entropy Density ◽  
Maximum Temperature ◽  
Past Century ◽  
Physical Point ◽  
Theory Of Gravity ◽  
The Universe

AbstractThe gravitational equations were derived in general relativity (GR) using the assumption of their covariance relative to arbitrary transformations of coordinates. It has been repeatedly expressed an opinion over the past century that such equality of all coordinate systems may not correspond to reality. Nevertheless, no actual verification of the necessity of this assumption has been made to date. The paper proposes a theory of gravity with a constraint, the degenerate variants of which are general relativity (GR) and the unimodular theory of gravity. This constraint is interpreted from a physical point of view as a sufficient condition for the adiabaticity of the process of the evolution of the space–time metric. The original equations of the theory of gravity with the constraint are formulated. On this basis, a unified model of the evolution of the modern, early, and very early Universe is constructed that is consistent with the observational astronomical data but does not require the hypotheses of the existence of dark energy, dark matter or inflatons. It is claimed that: physical time is anisotropic, the gravitational field is the main source of energy of the Universe, the maximum global energy density in the Universe was 64 orders of magnitude smaller the Planckian one, and the entropy density is 18 orders of magnitude higher the value predicted by GR. The value of the relative density of neutrinos at the present time and the maximum temperature of matter in the early Universe are calculated. The wave equation of the gravitational field is formulated, its solution is found, and the nonstationary wave function of the very early Universe is constructed. It is shown that the birth of the Universe was random.

scholarly journals New mechanism for the cosmological red-shift explaining: non-observation of dark energy, large-number- coincidence and the cosmic coincidence

2015 ◽  
Vol 3 (1) ◽  
pp. 24
Author(s):  
Hasmukh K. Tank
Keyword(s):  
Gravitational Field ◽  
Potential Energy ◽  
Gravitational Potential ◽  
Red Shift ◽  
Relativity Theory ◽  
Gravitational Potential Energy ◽  
Potential Well ◽  
Speed Of Light ◽  
Equivalent Mass ◽  
The Universe

<p>Accepting Einstein’s General Relativity Theory, that the changes in the gravitational field can propagate at the speed of light, it is proposed here that: before an electron in an atom emits a photon, the energy (<em>h f<sub>0</sub></em>) of the photon was a part of total energy of the atom; contributing to establish the gravitational-field around the atom. As soon as an electron in that atom emits a photon of energy <em>h f<sub>0</sub></em>, and the photon starts moving away from the atom, the gravitational-field around the atom partly reduces, proportional to the photon’s energy <em>h f<sub>0</sub></em>, and this wave of ‘reduced gravitational field’ propagates radially-outwards at the speed of light. And a part of energy of the photon gets spent in “filling” the ‘gravitational potential-well’ produced by its energy, when it was a part of energy of the atom. From the derivation presented here we find that the energy spent by the photon to “fill” the ‘gravitational potential-well’, during its inter-galactic journey manifests as the ‘cosmological red-shift’. And the so called ‘total-mass-of-the-universe'’ and ‘radius-of-the-universe'’ are just mathematically-equivalent mass and distance arising while converting electrostatic potential-energy into gravitational potential-energy. This is the reason why we find the large-number-coincidence (LNC). And since there is no expansion of the universe, there is no ‘cosmic coincidence’, that why only in this epoch we find the ‘large-number-coincidence’!</p>

Studying the Patterns of the Universe

2011 ◽  
Vol 20 (2) ◽  
Author(s):  
T. Sepp ◽  
E. Tempel ◽  
M. Gramann ◽  
P. Nurmi ◽  
M. Haupt
Keyword(s):  
Dark Matter ◽  
Galaxy Cluster ◽  
Analytical Models ◽  
Matter Distribution ◽  
Galaxy Groups ◽  
The Galaxy ◽  
Dark Matter Distribution ◽  
Distribution Studies ◽  
The Universe ◽  
Good Agreement

AbstractThe SDSS galaxy catalog is one of the best databases for galaxy distribution studies. The SDSS DR8 data is used to construct the galaxy cluster catalog. We construct the clusters from the calculated luminosity density field and identify denser regions. Around these peak regions we construct galaxy clusters. Another interesting question in cosmology is how observable galaxy structures are connected to underlying dark matter distribution. To study this we compare the SDSS DR7 galaxy group catalog with galaxy groups obtained from the semi-analytical Millennium N-Body simulation. Specifically, we compare the group richness, virial radius, maximum separation and velocity dispersion distributions and find a relatively good agreement between the mock catalog and observations. This strongly supports the idea that the dark matter distribution and galaxies in the semi-analytical models and observations are very closely linked.

3. Characterizing black holes

2015 ◽  
Author(s):  
Katherine Blundell
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Gravitational Field ◽  
Curved Spacetime ◽  
Remarkable Feature ◽  
Static Limit ◽  
Frame Dragging ◽  
Axis Of Rotation ◽  
Different Types

‘Characterizing black holes’ describes the two different types of black holes: Schwarzschild black holes that do not rotate and Kerr black holes that do. The only distinguishing characteristics of black holes are their mass and their spin. A remarkable feature of a spinning black hole is that the gravitational field pulls objects around the black hole’s axis of rotation, not merely in towards its centre—an effect called frame dragging. The static limit and ergosphere regions of black holes are also described. Einstein’s equations of General Relativity allow many different solutions describing alternative versions of curved spacetime. Could white holes and worm holes exist in our universe?

scholarly journals HST/COS Observations of Quasar Outflows in the 500–1050 Å Rest Frame. I. The Most Energetic Outflows in the Universe and Other Discoveries

2020 ◽  
Vol 247 (2) ◽  
pp. 37 ◽  
Author(s):  
Nahum Arav ◽  
Xinfeng Xu ◽  
Timothy Miller ◽  
Gerard A. Kriss ◽  
Rachel Plesha
Keyword(s):  
Rest Frame ◽  
The Universe
Sign in / Sign up

Export Citation Format

Share Document