scholarly journals Free-fall energy density and flux in the Schwarzschild black hole

2015 ◽  
Vol 30 (11) ◽  
pp. 1550053 ◽  
Author(s):  
Wontae Kim ◽  
Bibhas Ranjan Majhi
Keyword(s):  
Black Hole ◽  
Energy Density ◽  
Free Fall ◽  
Negative Energy ◽  
Schwarzschild Black Hole ◽  
Spatial Infinity ◽  
Negative Energy Density ◽  
Conformally Invariant ◽  
Trace Anomaly

In the four-dimensional background of Schwarzschild black hole, we investigate the energy densities and fluxes in the freely falling frames for the Boulware, Unruh, and Israel–Hartle–Hawking states. In particular, we study their behaviors near the horizon and asymptotic spatial infinity by using the trace anomaly of a conformally invariant scalar field. In the Boulware state, both the energy density and flux are negative divergent when the observer is dropped at the horizon, and asymptotically vanish. In the Unruh state, the energy density is also negative divergent at the horizon while it is positive finite asymptotically. The flux in the Unruh state is always positive and divergent at the horizon. In the Israel–Hartle–Hawking state, the energy density depends on the angular motion of free fall, and fluxes vanish at the horizon and the spatial infinity. Finally, we discuss the role of the negative energy density near the horizon in the evaporating black hole.

scholarly journals Something special at the event horizon

2014 ◽  
Vol 29 (40) ◽  
pp. 1450215 ◽  
Author(s):  
Myungseok Eune ◽  
Yongwan Gim ◽  
Wontae Kim
Keyword(s):  
Black Hole ◽  
Energy Density ◽  
Free Fall ◽  
Scalar Fields ◽  
Negative Energy ◽  
Two Dimensional ◽  
Schwarzschild Black Hole ◽  
Negative Energy Density ◽  
Trace Anomaly ◽  
Physical Consequences

We revisit the free-fall energy density of scalar fields semiclassically by employing the trace anomaly on a two-dimensional Schwarzschild black hole with respect to various black hole states in order to clarify whether something special at the horizon happens or not. For the Boulware state, the energy density at the horizon is always negative divergent, which is independent of initial free-fall positions. However, in the Unruh state the initial free-fall position is responsible for the energy density at the horizon and there is a critical point to determine the sign of the energy density at the horizon. In particular, a huge negative energy density appears when the freely falling observer is dropped just near the horizon. For the Hartle–Hawking state, it may also be positive or negative depending on the initial free-fall position, but it is always finite. Finally, we discuss physical consequences of these calculations.

scholarly journals Local free-fall temperature of modified Schwarzschild black hole in rainbow spacetime

2016 ◽  
Vol 31 (17) ◽  
pp. 1650106 ◽  
Author(s):  
Yong-Wan Kim ◽  
Young-Jai Park
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Test Particle ◽  
Free Fall ◽  
Local Temperature ◽  
Schwarzschild Black Hole ◽  
Energy Formula ◽  
Fall Temperature ◽  
Flat Embedding

We obtain a (5+1)-dimensional global flat embedding of modified Schwarzschild black hole in rainbow gravity. We show that local free-fall temperature in rainbow gravity, which depends on different energy [Formula: see text] of a test particle, is finite at the event horizon for a freely falling observer, while local temperature is divergent at the event horizon for a fiducial observer. Moreover, these temperatures in rainbow gravity satisfy similar relations to those of the Schwarzschild black hole except the overall factor [Formula: see text], which plays a key role of rainbow functions in this embedding approach.

scholarly journals Freely falling observer and black hole radiation

2014 ◽  
Vol 29 (11) ◽  
pp. 1450052 ◽  
Author(s):  
Wontae Kim ◽  
Edwin J. Son
Keyword(s):  
Black Hole ◽  
Energy Density ◽  
Event Horizon ◽  
Negative Energy ◽  
Positive Energy ◽  
Energy Curve ◽  
Zero Energy ◽  
Negative Energy Density ◽  
Black Hole Radiation

We find radiation in an infalling frame and present an explicit analytic evidence of the failure of no drama condition by showing that an infalling observer finds an infinite negative energy density at the event horizon. The negative and positive energy density regions are divided by the newly defined zero-energy curve (ZEC). The evaporating black hole is surrounded by the negative energy which can also be observed in the infalling frame.

scholarly journals Unsettling Physics in the Quantum-Corrected Schwarzschild Black Hole

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1264 ◽  
Author(s):  
Valerio Faraoni ◽  
Andrea Giusti
Keyword(s):  
Black Hole ◽  
Energy Density ◽  
Circular Orbit ◽  
Loop Quantum Gravity ◽  
Schwarzschild Black Hole ◽  
Spatial Infinity ◽  
Quantum Energy ◽  
Stable Circular Orbit ◽  
Innermost Stable Circular Orbit ◽  
Quasilocal Mass

We study a quantum-corrected Schwarzschild black hole proposed recently in Loop Quantum Gravity. Prompted by the fact that corrections to the innermost stable circular orbit of Schwarzschild diverge, we investigate time-like and null radial geodesics. Massive particles moving radially outwards are confined, while photons make it to infinity with infinite redshift. This unsettling physics, which deviates radically from both Schwarzschild (near the horizon) and Minkowski (at infinity) is due to repulsion by the negative quantum energy density that makes the quasilocal mass vanish as one approaches spatial infinity.

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 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

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.

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