scholarly journals Virtual black holes in generalized dilaton theories

2003 ◽  
Vol 30 (1) ◽  
pp. 135-143 ◽  
Author(s):  
D. Grumiller ◽  
W. Kummer ◽  
D.V. Vassilevich
Keyword(s):  
Black Holes ◽  
Virtual Black Holes

scholarly journals Proton decay and the quantum structure of space–time

2019 ◽  
Vol 97 (12) ◽  
pp. 1317-1322
Author(s):  
Abeer Al-Modlej ◽  
Salwa Alsaleh ◽  
Hassan Alshal ◽  
Ahmed Farag Ali
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Coherent State ◽  
Dimensional Space ◽  
Space Time ◽  
Noncommutative Space ◽  
Quantum Structure ◽  
Dimensional Space Time ◽  
Proton Lifetime ◽  
Virtual Black Holes

Virtual black holes in noncommutative space–time are investigated using coordinate coherent state formalism such that the event horizon of a black hole is manipulated by smearing it with a Gaussian of width [Formula: see text], where θ is the noncommutativity parameter. Proton lifetime, the main associated phenomenology of the noncommutative virtual black holes, has been studied, first in four-dimensional space–time and then generalized to D dimensions. The lifetime depends on θ and the number of space–time dimensions such that it emphasizes on the measurement of proton lifetime as a potential probe for the microstructure of space–time.

QUANTUM GRAVITATIONAL EFFECTS AND THE COMPACTIFICATION SCALE IN THE HETEROTIC SUPERSTRING THEORY

1999 ◽  
Vol 14 (01) ◽  
pp. 119-127 ◽  
Author(s):  
M. D. POLLOCK
Keyword(s):  
Black Holes ◽  
Wormhole Solution ◽  
Superstring Theory ◽  
Gravitational Effects ◽  
Parity Symmetry ◽  
Anomalous Term ◽  
Higher Derivative ◽  
Euclidean Action ◽  
Model Independent ◽  
Virtual Black Holes

It is known that quantum gravitational effects due to virtual black holes and wormholes can exert an important influence by violating global symmetries. These processes have recently been investigated by Kallosh et al., who found, for the heterotic superstring theory, that there is a sufficient suppression of deleterious effects via the Euclidean action S E from the presence of higher-derivative terms occurring as a topological invariant, the Euler characteristic χ, regardless of the precise details of the underlying wormhole solution. Here, we consider this result further, arguing, in the absence of inflation, that there are no large wormholes in the heterotic superstring theory for which the wormhole action per se is large enough, topological suppression being the only possibility. The model-independent superstring axion may be susceptible to these corrections, because, as shown by Witten, it possesses a non-linearly realized, global U(1) symmetry, being a real scalar field coupled to the anomalous term [Formula: see text] from the outset, and they are relevant to the R-parity symmetry. Allowing for the unknown effect of the black holes, however, we conjecture that these quantum gravitational effects produce no observable consequences.

scholarly journals Loss of quantum coherence through scattering off virtual black holes

1997 ◽  
Vol 56 (10) ◽  
pp. 6403-6415 ◽  
Author(s):  
S. W. Hawking ◽  
Simon F. Ross
Keyword(s):  
Black Holes ◽  
Quantum Coherence ◽  
Virtual Black Holes

scholarly journals Virtual black holes

1996 ◽  
Vol 53 (6) ◽  
pp. 3099-3107 ◽  
Author(s):  
S. W. Hawking
Keyword(s):  
Black Holes ◽  
Virtual Black Holes

scholarly journals ∞-∞: Vacuum energy and virtual black holes

2016 ◽  
Vol 116 (2) ◽  
pp. 20003 ◽  
Author(s):  
Andrea Addazi
Keyword(s):  
Black Holes ◽  
Vacuum Energy ◽  
Virtual Black Holes

scholarly journals ER = EPR and non-perturbative action integrals for quantum gravity

2017 ◽  
Vol 14 (10) ◽  
pp. 1750138
Author(s):  
Salwa Alsaleh ◽  
Lina Alasfar
Keyword(s):  
Black Holes ◽  
Quantum Gravity ◽  
Betti Number ◽  
Path Integrals ◽  
Proper Choice ◽  
Homotopy Classes ◽  
Multiply Connected ◽  
Spacetime Manifold ◽  
Number Formula ◽  
Virtual Black Holes

In this paper, we construct and calculate non-perturbative path integrals in a multiply-connected spacetime. This is done by summing over homotopy classes of paths. The topology of the spacetime is defined by Einstein–Rosen bridges (ERB) forming from the entanglement of quantum foam described by virtual black holes. As these “bubbles” are entangled, they are connected by Planckian ERBs because of the [Formula: see text] conjecture. Hence, the spacetime will possess a large first Betti number [Formula: see text]. For any compact 2-surface in the spacetime, the topology (in particular the homotopy) of that surface is non-trivial due to the large number of Planckian ERBs that define homotopy through this surface. The quantization of spacetime with this topology — along with the proper choice of the 2-surfaces — is conjectured to allow non-perturbative path integrals of quantum gravity theory over the spacetime manifold.

scholarly journals Virtual black holes in a third quantized formalism

2017 ◽  
Vol 384 ◽  
pp. 105-115 ◽  
Author(s):  
Yoshiaki Ohkuwa ◽  
Mir Faizal ◽  
Yasuo Ezawa
Keyword(s):  
Black Holes ◽  
Virtual Black Holes

Virtual Black Holes and Space–Time Structure

2018 ◽  
Vol 48 (10) ◽  
pp. 1134-1149 ◽  
Author(s):  
Gerard ’t Hooft
Keyword(s):  
Black Holes ◽  
Space Time ◽  
Time Structure ◽  
Space Time Structure ◽  
Virtual Black Holes
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