scholarly journals Limits on spacetime foam

2011 ◽  
Vol 83 (8) ◽  
Author(s):  
Wayne A. Christiansen ◽  
Y. Jack Ng ◽  
David J. E. Floyd ◽  
Eric S. Perlman
Keyword(s):  
Spacetime Foam

scholarly journals INTERFACE OF GRAVITATIONAL AND QUANTUM REALMS

2002 ◽  
Vol 17 (15n17) ◽  
pp. 1135-1145 ◽  
Author(s):  
D. V. AHLUWALIA
Keyword(s):  
Quantum Gravity ◽  
Quantum Interference ◽  
Physical Reality ◽  
Superconducting Quantum Interference Devices ◽  
Superconducting Quantum Interference ◽  
Quantum Gravity Phenomenology ◽  
Wave Particle Duality ◽  
General Relativistic ◽  
Relativistic Description ◽  
Spacetime Foam

The talk centers around the question: Can general-relativistic description of physical reality be considered complete? On the way I argue how – unknown to many a physicists, even today – the "forty orders of magnitude argument" against quantum gravity phenomenology was defeated more than a quarter of a century ago, and how we now stand at the possible verge of detecting a signal for the spacetime foam, and studying the gravitationally-modified wave particle duality using superconducting quantum interference devices.

scholarly journals On the detectability of quantum spacetime foam with gravitational-wave interferometers

2000 ◽  
Vol 477 (4) ◽  
pp. 424-428 ◽  
Author(s):  
Ronald J. Adler ◽  
Ilya M. Nemenman ◽  
James M. Overduin ◽  
David I. Santiago
Keyword(s):  
Gravitational Wave ◽  
Spacetime Foam ◽  
Quantum Spacetime

scholarly journals A Spacetime Foam Approach to the Schwarzschild-de Sitter Entropy

Entropy ◽  
2000 ◽  
Vol 2 (1) ◽  
pp. 26-38 ◽  
Author(s):  
Remo Garattini
Keyword(s):  
De Sitter ◽  
Spacetime Foam

scholarly journals Spacetime Foam and Dark Energy

2009 ◽  
Author(s):  
Y. Jack Ng ◽  
Shaaban Khalil
Keyword(s):  
Dark Energy ◽  
Spacetime Foam

scholarly journals Spacetime Foam, Midisuperspace, and the Cosmological Constant

Universe ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 495
Author(s):  
Steven Carlip
Keyword(s):  
Cosmological Constant ◽  
Time Evolution ◽  
Planck Scale ◽  
Quantum Fluctuations ◽  
Spacetime Foam

Perhaps the cosmological constant really is huge at the Planck scale, but is “hidden” by Planck scale quantum fluctuations of spacetime. I briefly review this proposal and provide some evidence, coming from a simplified midisuperspace model, that an appropriate “foamy” structure can do the job of hiding a large cosmological constant, and can persist under time evolution.

scholarly journals Midisuperspace foam and the cosmological constant

2021 ◽  
Author(s):  
Steven Carlip
Keyword(s):  
Initial Data ◽  
Quantum Gravity ◽  
Cosmological Constant ◽  
Spherical Symmetry ◽  
Planck Scale ◽  
Stationary States ◽  
Infinite Class ◽  
Probability Current ◽  
Spacetime Foam ◽  
Large Quantum

Abstract Wheeler's conjectured "spacetime foam" -- large quantum fluctuations of spacetime at the Planck scale -- could have important implications for quantum gravity, perhaps even explaining why the cosmological constant seems so small. Here I explore this problem in a midisuperspace model consisting of metrics with local spherical symmetry. Classically, an infinite class of ``foamy'' initial data can be constructed, in which cancellations between expanding and contracting regions lead to a small average expansion even if Λ is large. Quantum mechanically, the model admits corresponding stationary states, for which the probability current is also nearly zero. These states appear to describe a self-reproducing spacetime foam with very small average expansion, effectively hiding the cosmological constant.

scholarly journals A new type of nonsingular black-hole solution in general relativity

2014 ◽  
Vol 29 (19) ◽  
pp. 1430018 ◽  
Author(s):  
F. R. Klinkhamer
Keyword(s):  
Black Hole ◽  
Spherically Symmetric ◽  
Curvature Singularity ◽  
Einstein Field Equations ◽  
Field Equations ◽  
Schwarzschild Solution ◽  
Gravity Effects ◽  
New Type ◽  
Nontrivial Topology ◽  
Spacetime Foam

Certain exact solutions of the Einstein field equations over nonsimply-connected manifolds are reviewed. These solutions are spherically symmetric and have no curvature singularity. They provide a regularization of the standard Schwarzschild solution with a curvature singularity at the center. Spherically symmetric collapse of matter in ℝ4 may result in these nonsingular black-hole solutions, if quantum-gravity effects allow for topology change near the center or if nontrivial topology is already present as a remnant from a quantum spacetime foam.

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