scholarly journals Local free-fall temperature of Gibbons-Maeda-Garfinkle-Horowitz-Strominger black holes

2014 ◽  
Vol 89 (4) ◽  
Author(s):  
Yong-Wan Kim ◽  
Jaedong Choi ◽  
Young-Jai Park
Keyword(s):  
Black Holes ◽  
Free Fall ◽  
Fall Temperature

scholarly journals LOCAL FREE-FALL TEMPERATURE OF A RN–AdS BLACK HOLE

2010 ◽  
Vol 25 (15) ◽  
pp. 3107-3120 ◽  
Author(s):  
YONG-WAN KIM ◽  
JAEDONG CHOI ◽  
YOUNG-JAI PARK
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Minkowski Space ◽  
Event Horizon ◽  
Free Fall ◽  
Flat Space ◽  
Space Time ◽  
Local Temperature ◽  
Static Black Hole ◽  
Fall Temperature

We use the global embedding Minkowski space geometries of a (3+1)-dimensional curved Reissner–Nordström (RN)–AdS black hole space–time into a (5+2)-dimensional flat space–time to define a proper local temperature, which remains finite at the event horizon, for freely falling observers outside a static black hole. Our extended results include the known limiting cases of the RN, Schwarzschild–AdS and Schwarzschild black holes.

scholarly journals Gauge dependence and self-force from Galilean to Einsteinian free fall, compact stars falling into black holes, Hawking radiation and the Pisa tower at the general relativity centennial

2016 ◽  
Vol 13 (08) ◽  
pp. 1630014 ◽  
Author(s):  
Alessandro D. A. M. Spallicci ◽  
Maurice H. P. M. van Putten
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Undergraduate Students ◽  
Hawking Radiation ◽  
Mass Formula ◽  
Center Of Mass ◽  
Free Fall ◽  
Compact Stars ◽  
Self Force

Obviously, in Galilean physics, the universality of free fall implies an inertial frame, which in turns implies that the mass [Formula: see text] of the falling body is omitted (because it is a test mass; put otherwise, the center of mass of the system coincides with the center of the main, and fixed, mass [Formula: see text]; or else, we consider only a homogeneous gravitational field). Conversely, an additional (in the opposite or same direction) acceleration proportional to [Formula: see text] would rise either for an observer at the center of mass of the system, or for an observer at a fixed distance from the center of mass of [Formula: see text]. These elementary, but overlooked, considerations fully respect the equivalence principle (EP) and the (local) identity of an inertial or a gravitational pull for an observer in the Einstein cabin. They value as fore-runners of the self-force and gauge dependency in general relativity. Because of its importance in teaching and in the history of physics, coupled to the introductory role to Einstein’s EP, the approximate nature of Galilei’s law of free fall is explored herein. When stepping into general relativity, we report how the geodesic free fall into a black hole was the subject of an intense debate again centered on coordinate choice. Later, we describe how the infalling mass and the emitted gravitational radiation affect the free fall motion of a body. The general relativistic self-force might be dealt with to perfectly fit into a geodesic conception of motion. Then, embracing quantum mechanics, real black holes are not classical static objects any longer. Free fall has to handle the Hawking radiation, and leads us to new perspectives on the varying mass of the evaporating black hole and on the varying energy of the falling mass. Along the paper, we also estimate our findings for ordinary masses being dropped from a Galilean or Einsteinian Pisa-like tower with respect to the current state of the art drawn from precise measurements in ground and space laboratories, and to the constraints posed by quantum measurements. Appendix A describes how education physics and high impact factor journals discuss the free fall. Finally, case studies conducted on undergraduate students and teachers are reviewed.

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.

Black holes in the theory of the dynamic medium of reference

2020 ◽  
Vol 33 (4) ◽  
pp. 395-399
Author(s):  
Olivier Pignard
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Coordinate System ◽  
Free Fall ◽  
Local Measurement ◽  
Speed Of Light ◽  
Material Particle ◽  
Propagation Medium

The aim of this article is to apply the theory of the dynamic medium of reference [O. Pignard, Phys. Essays 32, 422 (2019)] to black holes and to find all the results of general relativity concerning black holes without rotation and without load. Among the most important results to which this article leads, we can mention: (1) The speed of the flux of the medium is greater than the speed of light inside the horizon of a black hole or even much greater than the speed of light at a distance from the center of the black hole much less than the radius of Schwarzschild. (2) In the hybrid coordinate system (drSchwarzschild, dtfree fall), the speed of light is established simply in relation to its propagation medium. (3) A photon emitted at an infinite distance from the black hole with speed c 0 arrives near the horizon of the black hole with a real speed zero. And yet the local measurement of the speed of the photon carried out with a material clock and a material ruler remains c 0. (4) Study of the possible orbits of a material particle around a black hole and the possibility of orbits of a photon around a black hole.

Traversing a black-and-white hole in free fall and rise

2020 ◽  
Vol 33 (4) ◽  
pp. 460-465
Author(s):  
Andreas Trupp
Keyword(s):  
Black Holes ◽  
Gravity Field ◽  
Free Fall ◽  
Spherical Body ◽  
Relativity Principle ◽  
White Hole ◽  
Schwarzschild Metric ◽  
Temporal Interval ◽  
Black And White ◽  
Schwarzschild Radius

It is shown that a traverse of a Black-and-White Hole (through a shaft in the interior of the central, spherical body) in free radial fall and rise is described by the Schwarzschild metric without any ambiguity. In other words, all Black Holes can also be White Holes. The relativity principle, according to which both the freely falling/rising observer Alice and a second observer Bob (sitting outside of the gravity field) have to measure the same temporal interval for the complete trip, is observed [(Δt)/(Δτ) = 1]. In the interior of the Schwarzschild radius, Alice's time τ is reversed. Kruskal charts do not present an obstacle to this result, since quadrant II can be used for ingoing traffic only, but not for outgoing traffic.

scholarly journals Local free-fall temperatures of charged BTZ black holes in massive gravity

2019 ◽  
Vol 99 (2) ◽  
Author(s):  
Soon-Tae Hong ◽  
Yong-Wan Kim ◽  
Young-Jai Park
Keyword(s):  
Black Holes ◽  
Free Fall ◽  
Massive Gravity ◽  
Btz Black Holes
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