scholarly journals THE QUANTUM GRAVITY WITH TORSION AND GHOST-FREE DE SITTER GRAVITY (Ⅱ)——CHOST-FREE PROPERTY OF SO(3,2) DE SITTER GRAVITY

1984 ◽  
Vol 33 (10) ◽  
pp. 1386
Author(s):  
YAN MU-LIN ◽  
GUO HAN-YING
Keyword(s):  
Quantum Gravity ◽  
De Sitter

scholarly journals Aspects of quantum gravity in de Sitter spaces

2004 ◽  
Vol 2004 (11) ◽  
pp. 006-006 ◽  
Author(s):  
Dietmar Klemm ◽  
Luciano Vanzo
Keyword(s):  
Quantum Gravity ◽  
De Sitter

scholarly journals Evaporation of black hole under the effect of quantum gravity

2021 ◽  
Author(s):  
Riasat Ali ◽  
Rimsha Babar ◽  
Muhammad Asgher ◽  
Syed Asif Ali Shah
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Generalized Uncertainty Principle ◽  
Hawking Temperature ◽  
Charged Black Hole ◽  
Global Monopole ◽  
De Sitter ◽  
Quantum Radiation ◽  
Charged Boson

This paper provides an extension for Hawking temperature of Reissner–Nordström-de Sitter (RN-DS) black hole (BH) with global monopole as well as [Formula: see text]D charged black hole. We consider the black holes metric and investigate the effects of quantum gravity ([Formula: see text]) on Hawking radiation. We investigate the charged boson particles tunneling through the horizon of black holes by using the Hamilton–Jacobi ansatz phenomenon. In our investigation, we study the quantum radiation to analyze the Lagrangian wave equation with generalized uncertainty principle and calculate the modified Hawking temperatures for black holes. Furthermore, we analyze the charge and correction parameter effects on the modified Hawking temperature and examine the stable and unstable condition of RN-DS BH with global monopole as well as [Formula: see text]D charged black hole.

scholarly journals Comment on Coleman-DeLuccia instantons

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Thomas Banks ◽  
Bingnan Zhang
Keyword(s):  
Models Of Quantum Gravity ◽  
Quantum Gravity ◽  
Transition Probabilities ◽  
Detailed Balance ◽  
De Sitter Space ◽  
Positive Energy ◽  
De Sitter ◽  
Finite Area ◽  
Quantum Models

We complete an old argument that causal diamonds in the crunching region of the Lorentzian continuation of a Coleman-Deluccia instanton for transitions out of de Sitter space have finite area, and provide quantum models consistent with the principle of detailed balance, which can mimic the instanton transition probabilities for the cases where this diamond is larger or smaller than the causal patch of de Sitter space. We review arguments that potentials which do not have a positive energy theorem when the lowest de Sitter minimum is shifted to zero, may not correspond to real models of quantum gravity.

scholarly journals Role of Quantum Entropy and Establishment of H-Theorems in the Presence of Graviton Sinks for Manifestly-Covariant Quantum Gravity

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 418 ◽  
Author(s):  
Massimo Tessarotto ◽  
Claudio Cremaschini
Keyword(s):  
Quantum Gravity ◽  
Gaussian Function ◽  
Quantum Probability ◽  
De Sitter ◽  
Covariant Quantum ◽  
Generalized Lagrangian ◽  
Quantum Wave ◽  
H Theorem

Based on the introduction of a suitable quantum functional, identified here with the Boltzmann–Shannon entropy, entropic properties of the quantum gravitational field are investigated in the framework of manifestly-covariant quantum gravity theory. In particular, focus is given to gravitational quantum states in a background de Sitter space-time, with the addition of possible quantum non-unitarity effects modeled in terms of an effective quantum graviton sink localized near the de Sitter event horizon. The theory of manifestly-covariant quantum gravity developed accordingly is shown to retain its emergent-gravity features, which are recovered when the generalized-Lagrangian-path formalism is adopted, yielding a stochastic trajectory-based representation of the quantum wave equation. This permits the analytic determination of the quantum probability density function associated with the quantum gravity state, represented in terms of a generally dynamically-evolving shifted Gaussian function. As an application, the study of the entropic properties of quantum gravity is developed and the conditions for the existence of a local H-theorem or, alternatively, of a constant H-theorem are established.

scholarly journals Dark energy and quantum gravity

2019 ◽  
Vol 28 (14) ◽  
pp. 1944018 ◽  
Author(s):  
Per Berglund ◽  
Tristan Hübsch ◽  
Djordje Minić
Keyword(s):  
Dark Energy ◽  
String Theory ◽  
Quantum Gravity ◽  
Cosmological Constant ◽  
Particle Physics ◽  
Dual Space ◽  
Planck Scale ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Sitter Spacetime

Realizing dark energy and the observed de Sitter spacetime in quantum gravity has proven to be obstructed in almost every usual approach. We argue that additional degrees of freedom of the left- and right-movers in string theory and a resulting doubled, noncommutatively generalized geometric formulation thereof can lead to an effective model of dark energy consistent with de Sitter spacetime. In this approach, the curvature of the canonically conjugate dual space provides for the dark energy inducing a positive cosmological constant in the observed spacetime, whereas the size of the above dual space is the gravitational constant in the same observed de Sitter spacetime. As a hallmark relation owing to a unique feature of string theory which relates short distances to long distances, the cosmological constant scale, the Planck scale and the effective TeV-sized particle physics scale must satisfy a see-saw-like formula — precisely the generic prediction of certain stringy cosmic brane type models.

The remnants in Reissner–Nordström–de Sitter quintessence black hole

2014 ◽  
Vol 29 (26) ◽  
pp. 1450123 ◽  
Author(s):  
Zhongwen Feng ◽  
Li Zhang ◽  
Xiaotao Zu
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Quantum Number ◽  
Information Loss ◽  
De Sitter ◽  
Information Loss Paradox

According to the effects of quantum gravity, we investigated the fermion tunneling from the Reissner–Nordström–de Sitter quintessence (RN–dSQ) black hole. The corrected temperature is not only determined by the mass and charge of the black hole, but also depended on the quantum number of the emitted fermion and β, which is a small value representing the effects of quantum gravity. The effects of quantum gravity slowed down the increase of the temperature and led to the remnants of the black hole. We think it is a method to avoid the information loss paradox of black holes.

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