scholarly journals Relating follicly-challenged compact stars to bald black holes: A link between two no-hair properties

2015 ◽  
Vol 91 (10) ◽  
Author(s):  
Kent Yagi ◽  
Nicolás Yunes
Keyword(s):  
Black Holes ◽  
Compact Stars ◽  
Hair Properties

Compact Stars: From Dwarfs to Black Holes

2007 ◽  
pp. 70-186
Author(s):  
Norman K. Glendenning
Keyword(s):  
Black Holes ◽  
Compact Stars

scholarly journals Electrically charged compact stars and formation of charged black holes

2003 ◽  
Vol 68 (8) ◽  
Author(s):  
Subharthi Ray ◽  
Aquino L. Espíndola ◽  
Manuel Malheiro ◽  
José P. S. Lemos ◽  
Vilson T. Zanchin
Keyword(s):  
Black Holes ◽  
Compact Stars ◽  
Charged Black Holes ◽  
Electrically Charged

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 NON-INERTIAL EFFECTS IN REACTIONS OF ASTROPHYSICAL INTEREST

2009 ◽  
Vol 24 (14) ◽  
pp. 1109-1120
Author(s):  
C. A. BERTULANI ◽  
J. T. HUANG ◽  
P. G. KRASTEV
Keyword(s):  
Black Holes ◽  
Nuclear Reactions ◽  
Compact Stars ◽  
Inertial Effects ◽  
Inertial Motion ◽  
Astrophysical Interest ◽  
Gravitational Fields ◽  
Atomic Transitions ◽  
Nuclear Collisions ◽  
Strong Gravitational Fields

We discuss the effects of non-inertial motion in reactions occurring in laboratory, stars, and elsewhere. It is demonstrated that non-inertial effects due to large accelerations during nuclear collisions might have appreciable effects nuclear and atomic transitions. We also explore the magnitude of the corrections induced by strong gravitational fields on nuclear reactions in massive, compact stars, and the neighborhood of black holes.

scholarly journals Temperature oscillations of a gas moving close to circular geodesic in Reissner–Nordström spacetime

2019 ◽  
Vol 28 (04) ◽  
pp. 1950059 ◽  
Author(s):  
Leandro Cesar Mehret ◽  
Gilberto Medeiros Kremer
Keyword(s):  
Black Holes ◽  
Electric Charge ◽  
Periodic Oscillation ◽  
Compact Stars ◽  
Quark Stars ◽  
Temperature Oscillations ◽  
Inverse Effect ◽  
Low Mass ◽  
X Ray Binaries

The objective of this work is to analyze the temperature oscillations that occur in a gas in a circular motion under the action of a Reissner–Nordström gravitational field, verifying the effect of the charge term of the metric on the oscillations. The expression for temperature oscillations follows from Tolman’s law written in Fermi normal coordinates for a comoving observer. The motion of the gas is close to geodesic so the equation of geodesic deviation was used to obtain the expression for temperature oscillations. Then these oscillations are calculated for some compact stars, quark stars, black holes and white dwarfs, using values of electric charge and mass from models found in the literature. Comparing the various models analyzed, it is possible to verify that the role of the charge is the opposite of the mass. While the increase of the mass produces a reduction in the frequencies, amplitude and, in the ratio between the frequencies, the increase of the electric charge produces the inverse effect. In addition, it is shown that if the electric charge is proportional to the mass, the ratio between the frequencies does not depend on the mass, but only on the proportionality factor between charge and mass. The ratios between the frequencies for all the models analyzed (except for supermassive black holes in the extreme limit situations) are close to the [Formula: see text] ratio for twin peak quasi-periodic oscillation (QPO) frequencies, observed in many galactic black holes and neutron star sources in low-mass X-ray binaries.

scholarly journals A conjectured universal relation for black holes and horizonless compact stars

2021 ◽  
pp. 115485
Author(s):  
Guohua Liu ◽  
Yan Peng
Keyword(s):  
Black Holes ◽  
Compact Stars ◽  
Universal Relation

Black Hole, Neutron Star and Numerical Relativity

2021 ◽  
Vol 30 (6) ◽  
pp. 7-13
Author(s):  
Jinho KIM
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Neutron Star ◽  
Neutron Stars ◽  
Numerical Method ◽  
High Velocity ◽  
Compact Objects ◽  
Compact Stars ◽  
Speed Of Light

Compact stars, e.g., black holes and neutron stars, are the most energetic objects in astrophysics. These objects are accompanied by extremely strong gravity and a high velocity, which approaches the speed of light. Therefore, compact objects should be dealt with in Einstein’s relativity. This article will briefly introduce a numerical method that will allow us to obtain general solutions in general relativity. Several applications using numerical relativistic simulations will also be presented.

scholarly journals I -Love- Q relations: from compact stars to black holes

2016 ◽  
Vol 33 (9) ◽  
pp. 095005 ◽  
Author(s):  
Kent Yagi ◽  
Nicolás Yunes
Keyword(s):  
Black Holes ◽  
Compact Stars

scholarly journals ASCA observation of ω Centauri

1996 ◽  
Vol 174 ◽  
pp. 353-354
Author(s):  
H. Negoro ◽  
K. Kawashima
Keyword(s):  
Black Holes ◽  
Neutron Stars ◽  
Globular Clusters ◽  
White Dwarfs ◽  
Compact Stars ◽  
Binary Formation ◽  
History Of

The number of compact stars such as white dwarfs, neutron stars, and black holes in globular clusters gives us information on binary formation rates and dynamical history of the clusters.

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