scholarly journals CLASSICAL ELECTRON MODEL WITH NEGATIVE ENERGY DENSITY IN EINSTEIN–CARTAN THEORY OF GRAVITATION

2004 ◽  
Vol 13 (03) ◽  
pp. 555-565 ◽  
Author(s):  
SAIBAL RAY ◽  
SUMANA BHADRA
Keyword(s):  
Energy Density ◽  
Negative Energy ◽  
Experimental Result ◽  
Theory Of Relativity ◽  
General Theory Of Relativity ◽  
Electron Model ◽  
Classical Electron ◽  
Negative Energy Density ◽  
Theory Of Gravitation ◽  
Cartan Theory

Experimental result regarding the maximum limit of the radius of the electron (~10-16 cm ) and a few of the theoretical works suggest that there might be some negative energy density regions within the particle in the general theory of relativity. It is argued in the present investigation that such a negative energy density also can be obtained with a better physical interpretation in the framework of Einstein–Cartan theory.

NEGATIVE ENERGY DENSITY IN SPINNING MATTER SOURCES IN WORMHOLE SPACE–TIMES WITH TORSION

1998 ◽  
Vol 13 (38) ◽  
pp. 3069-3072
Author(s):  
L. C. GARCIA DE ANDRADE
Keyword(s):  
Energy Density ◽  
Spin Density ◽  
Gravitational Collapse ◽  
Negative Pressure ◽  
Negative Energy ◽  
Space Time ◽  
Negative Energy Density ◽  
Traversable Wormholes ◽  
Radial Tension

Negative energy densities in spinning matter sources of non-Riemannian ultrastatic traversable wormholes require the spin energy density to be higher than the negative pressure or the radial tension. Since the radial tension necessary to support wormholes is higher than the spin density in practice, it seems very unlikely that wormholes supported by torsion may exist in nature. This result corroborates earlier results by Soleng against the construction of the closed time-like curves (CTC) in space–time geometries with spin and torsion. It also agrees with earlier results by Kerlick according to which Einstein–Cartan (EC) gravity torsion sometimes enhance the gravitational collapse instead of avoiding it.

scholarly journals Worldline numerics applied to custom Casimir geometry generates unanticipated intersection with Alcubierre warp metric

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
Harold White ◽  
Jerry Vera ◽  
Arum Han ◽  
Alexander R. Bruccoleri ◽  
Jonathan MacArthur
Keyword(s):  
Energy Density ◽  
Three Dimensional ◽  
Casimir Energy ◽  
Negative Energy ◽  
Vacuum Model ◽  
Energy Density Distribution ◽  
Dynamic Vacuum ◽  
Negative Energy Density ◽  
Funded Project ◽  
Transient Electric Field

AbstractWhile conducting analysis related to a DARPA-funded project to evaluate possible structure of the energy density present in a Casimir cavity as predicted by the dynamic vacuum model, a micro/nano-scale structure has been discovered that predicts negative energy density distribution that closely matches requirements for the Alcubierre metric. The simplest notional geometry being analyzed as part of the DARPA-funded work consists of a standard parallel plate Casimir cavity equipped with pillars arrayed along the cavity mid-plane with the purpose of detecting a transient electric field arising from vacuum polarization conjectured to occur along the midplane of the cavity. An analytic technique called worldline numerics was adapted to numerically assess vacuum response to the custom Casimir cavity, and these numerical analysis results were observed to be qualitatively quite similar to a two-dimensional representation of energy density requirements for the Alcubierre warp metric. Subsequently, a toy model consisting of a 1 $$\upmu $$ μ m diameter sphere centrally located in a 4 $$\upmu $$ μ m diameter cylinder was analyzed to show a three-dimensional Casimir energy density that correlates well with the Alcubierre warp metric requirements. This qualitative correlation would suggest that chip-scale experiments might be explored to attempt to measure tiny signatures illustrative of the presence of the conjectured phenomenon: a real, albeit humble, warp bubble.

scholarly journals A new result under weak and non-relativistic approximation from general theory of relativity

2021 ◽  
Author(s):  
Abhijit Samanta
Keyword(s):  
Field Equation ◽  
Energy Density ◽  
General Theory ◽  
Force Field ◽  
Coordinate System ◽  
Theory Of Relativity ◽  
General Theory Of Relativity ◽  
Inertial Coordinate System ◽  
Relativistic Approximation ◽  
Moving Particle

Abstract We have derived a metric field equation in the locally inertial coordinate system from Einstein's field equation considering the energy density of the moving particle with the approximations that the force field under which the particle is moving is weak and the velocity of the particle is non-relativistic. We study the motion of different microscopic systems using this metric equation and compared the results with the experimentally measured values and we find that the results are identical.

scholarly journals NEGATIVE ENERGY DENSITIES IN QUANTUM FIELD THEORY

2010 ◽  
Vol 25 (11) ◽  
pp. 2355-2363 ◽  
Author(s):  
L. H. FORD
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Energy Density ◽  
Negative Energy ◽  
Mean Value ◽  
Quantum Field ◽  
Two Dimensional ◽  
Vacuum Fluctuations ◽  
Negative Energy Density ◽  
Dimensional Spacetime

Quantum field theory allows for the suppression of vacuum fluctuations, leading to sub-vacuum phenomena. One of these is the appearance of local negative energy density. Selected aspects of negative energy will be reviewed, including the quantum inequalities which limit its magnitude and duration. However, these inequalities allow the possibility that negative energy and related effects might be observable. Some recent proposals for experiments to search for sub-vacuum phenomena will be discussed. Fluctuations of the energy density around its mean value will also be considered, and some recent results on a probability distribution for the energy density in two dimensional spacetime are summarized.

Restrictions on negative energy density for the Dirac field in flat spacetime

2006 ◽  
Vol 15 (5) ◽  
pp. 934-939 ◽  
Author(s):  
Shu Wei-Xing ◽  
Yu Hong-Wei ◽  
Li Fei ◽  
Wu Pu-Xun ◽  
Ren Zhong-Zhou
Keyword(s):  
Energy Density ◽  
Negative Energy ◽  
Dirac Field ◽  
Negative Energy Density ◽  
Flat Spacetime

An Action-at-a-Distance Theory of Gravitation

1971 ◽  
Vol 49 (2) ◽  
pp. 201-217 ◽  
Author(s):  
A. B. Volkov
Keyword(s):  
Momentum Conservation ◽  
Dielectric Dispersion ◽  
Interaction Theory ◽  
Theory Of Relativity ◽  
General Theory Of Relativity ◽  
Vector Interaction ◽  
Perihelion Advance ◽  
Theory Of Gravitation ◽  
Action At A Distance ◽  
Energy And Momentum

An action-at-a-distance theory is formulated as a possible alternative to the general theory of relativity. The observed gravitational frequency shift and light bending are obtained by photon energy and momentum conservation effects and gravitational–electromagnetic phenomena are interpreted in analogy with the quantum theory of dielectric dispersion. The observed perihelion advance of Mercury is obtained by a combined scalar and vector interaction theory of the Wheeler–Feynman type. The vector interaction is no longer excluded by conventional field theoretic arguments.

scholarly journals MACROLENSING SIGNATURES OF LARGE-SCALE VIOLATIONS OF THE WEAK ENERGY CONDITION

2001 ◽  
Vol 16 (03) ◽  
pp. 153-162 ◽  
Author(s):  
MARGARITA SAFONOVA ◽  
DIEGO F. TORRES ◽  
GUSTAVO E. ROMERO
Keyword(s):  
Energy Density ◽  
Large Scale ◽  
Energy Condition ◽  
Background Field ◽  
Negative Energy ◽  
Energy Conditions ◽  
Negative Energy Density ◽  
Time Domains ◽  
Deep Fields ◽  
Central Void

We present a set of simulations of the macrolensing effects produced by large-scale cosmological violations of the energy conditions. These simulations show how the appearance of a background field of galaxies is affected when lensed by a region with an energy density equivalent to a negative mass ranging from 1012 to 1017|M⊙|. We compare with the macrolensing results of equal amounts of positive mass, and show that, contrary to the usual case where tangential arc-like structures are expected, there appear radial arcs — runaway filaments — and a central void. These results make the cosmological macrolensing produced by space–time domains where the weak energy conditions are violated, observationally distinguishable from standard regions. Whether large domains with negative energy density indeed exist in the universe can now be decided by future observations of deep fields.

scholarly journals MATHEMATICAL EXPANSION OF SPECIAL THEORY OF RELATIVITY ONTO ACCELERATIONS

2021 ◽  
Vol 4 (1) ◽  
pp. 69-89
Author(s):  
Jakub Czajko
Keyword(s):  
Proper Time ◽  
Special Theory ◽  
Lorentz Factor ◽  
Theory Of Relativity ◽  
General Theory Of Relativity ◽  
Special Theory Of Relativity ◽  
Accelerator Pedal ◽  
Earth Gravity ◽  
Time Differential ◽  
Theory Of Gravitation

The special theory of relativity (STR) is operationally expanded onto orthogonal accelerations: normal  and binormal  that complement the instantaneous tangential speed  and thus can be structurally extended into operationally complete 4D spacetime without defying the STR. Thus the former classic Lorentz factor, which defines proper time differential  can be expanded onto  within a trihedron moving in the Frenet frame (T,N,B). Since the tangential speed  which was formerly assumed as being always constant, expands onto effective normal and binormal speeds ensuing from the normal and binormal accelerations, the expanded formula conforms to the former Lorentz factor. The obvious though previously overlooked fact that in order to change an initial speed one must apply accelerations (or decelerations, which are reverse accelerations), made the Einstein’s STR incomplete for it did not apply to nongravitational selfpropelled motion. Like a toy car lacking accelerator pedal, the STR could drive nowhere. Yet some scientists were teaching for over 115 years that the incomplete STR is just fine by pretending that gravity should take care of the absent accelerator. But gravity could not drive cars along even surface of earth. Gravity could only pull the car down along with the physics that peddled the nonsense while suppressing attempts at its rectification. The expanded formula neither defies the STR nor the general theory of relativity (GTR) which is just radial theory of gravitation. In fact, the expanded formula complements the STR and thus it supplements the GTR too. The famous Hafele-Keating experiments virtually confirmed the validity of the expanded formula proposed here.

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