Temperature dependent gravitational constant and black hole physics
TL;DR: In this article, the authors examined the thermodynamics of black holes in case of a varying gravitational constant and found that the second law of thermodynamics may remain valid contrary to the opinions expressed by some.
About: This article is published in Physics Letters B.The article was published on 1983-04-28. It has received 11 citations till now. The article focuses on the topics: Black hole thermodynamics & Black hole.
Citations
More filters
TL;DR: A short overview of black hole entropy in alternative gravitational theories is presented, which focuses on metric and Palatini ƒ(R) gravity and on scalar-tensor theories.
Abstract: A short overview of black hole entropy in alternative gravitational theories is presented. Motivated by the recent attempts to explain the cosmic acceleration without dark energy, we focus on metric and Palatini ƒ(R) gravity and on scalar-tensor theories.
77 citations
Cites background from "Temperature dependent gravitational..."
...The fact that the expression SBH = A 4G does not hold in alternative gravity has been known since the 1980s [53, 54, 55, 56, 58, 59, 60]....
[...]
TL;DR: In this paper, a short overview of black hole entropy in alternative gravitational theories is presented, motivated by the recent attempts to explain the cosmic acceleration without dark energy, focusing on metric and Palatini f(R) gravity and on scalar-tensor theories.
Abstract: A short overview of black hole entropy in alternative gravitational theories is presented. Motivated by the recent attempts to explain the cosmic acceleration without dark energy, we focus on metric and Palatini f(R) gravity and on scalar-tensor theories.
63 citations
TL;DR: Amal Kumar Raychaudhuri as discussed by the authors died on June 18, 2005 and his lecture which was given in honor of this great Indian scientist and teacher on December 26, 2005 in Puri, India.
Abstract: Amal Kumar Raychaudhuri died on June 18, 2005. This essay follows the lecture which was given in honor of this great Indian scientist and teacher on December 26, 2005 in Puri, India.
27 citations
TL;DR: Amal Kumar Raychaudhuri as discussed by the authors died on June 18, 2005. This essay follows the lecture which I gave in honour of this great Indian scientist and teacher on December 26, 2005 in Puri, India.
Abstract: Amal Kumar Raychaudhuri died on June 18, 2005. This essay follows the lecture which I gave in honour of this great Indian scientist and teacher on December 26, 2005 in Puri, India.
15 citations
TL;DR: A review of recent progress in the composite view of the Newtonian gravity constant can be found in this article , where the authors claim that the circular problem was solved a few years ago and that it is therefore of little or no use to express G through the Planck units.
Abstract: The Newtonian gravity constant G plays a central role in gravitational theory. Researchers have, since at least the 1980s, tried to see if the Newton gravitational constant can be expressed or replaced with more fundamental units, such as the Planck units. However, it was already pointed out in 1987 that this led to a circular problem; namely, that one must know G to find the Planck units, and that it is therefore of little or no use to express G through the Planck units. This is a view repeated in the literature in recent years, and is held by the physics’ community. However, we will claim that the circular problem was solved a few years ago. In addition, when one expresses the mass from the Compton wavelength formula, this leads to the conclusion that the three universal constants of G, h, and c now can be replaced with only lp and c to predict observable gravitational phenomena. While there have been several review papers on the Newton gravitational constant, for example, about how to measure it, we have not found a single review paper on the composite view of the gravitational constant. This paper will review the history of, as well as recent progress in, the composite view of the gravitational constant. This should hopefully be a useful supplement in the ongoing research for understanding and discussion of Newton’s gravitational constant.
8 citations
References
More filters
TL;DR: In this article, it is shown that quantum mechanical effects cause black holes to create and emit particles as if they were hot bodies with temperature, which leads to a slow decrease in the mass of the black hole and to its eventual disappearance.
Abstract: In the classical theory black holes can only absorb and not emit particles. However it is shown that quantum mechanical effects cause black holes to create and emit particles as if they were hot bodies with temperature\(\frac{{h\kappa }}{{2\pi k}} \approx 10^{ - 6} \left( {\frac{{M_ \odot }}{M}} \right){}^ \circ K\) where κ is the surface gravity of the black hole. This thermal emission leads to a slow decrease in the mass of the black hole and to its eventual disappearance: any primordial black hole of mass less than about 1015 g would have evaporated by now. Although these quantum effects violate the classical law that the area of the event horizon of a black hole cannot decrease, there remains a Generalized Second Law:S+1/4A never decreases whereS is the entropy of matter outside black holes andA is the sum of the surface areas of the event horizons. This shows that gravitational collapse converts the baryons and leptons in the collapsing body into entropy. It is tempting to speculate that this might be the reason why the Universe contains so much entropy per baryon.
10,923 citations
TL;DR: A theory of gravity incorporating the concept of spontaneous symmetry breaking is proposed in this article, where it is suggested that the same symmetry-breaking mechanism is responsible for breaking a unified gauge theory into strong, weak, and electromagnetic interactions.
Abstract: A theory of gravity incorporating the concept of spontaneous symmetry breaking is proposed. It is suggested that the same symmetry-breaking mechanism is responsible for breaking a unified gauge theory into strong, weak, and electromagnetic interactions.
417 citations
TL;DR: In this article, a new locally scale-invariant extension of general relativity is proposed based on Weyl's conformally invariant geometry, and it is shown that if the theory contains a Higgs phase, then it reduces to Einstein's theory in the limit of large distances.
220 citations
TL;DR: In this article, it was shown that in unified theories containing only fermions and gauge fields, radiative corrections induce an order-R$ term in the vacuum action functional which is uniquely determined by the flat-space-time theory.
Abstract: It is shown that in unified theories containing only fermions and gauge fields and in which scale invariance is spontaneously broken, radiative corrections induce an order-$R$ term in the vacuum action functional which is uniquely determined by the flat-space-time theory
139 citations
113 citations