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A coherent superposition of N Schwarzschild wormholes is proposed as a model for spacetime foam. Following the subtraction procedure for manifolds with boundaries, we calculate by variational methods the Casimir energy. A proposal for an…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Remo Garattini

The entropy for a black hole in a de Sitter space is approached within the framework of spacetime foam. A simple model, made by $N$ wormholes in a semiclassical approximation, is taken under examination to compute the entropy for such a…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Remo Garattini

Spacetime is composed of a fluctuating arrangement of bubbles or loops called spacetime foam, or quantum foam. We use the holographic principle to deduce its structure, and show that the result is consistent with gedanken experiments…

General Relativity and Quantum Cosmology · Physics 2011-09-01 Y. Jack Ng

In the context of a model of space-time foam, made by $N$ wormholes we discuss the possibility of having a foam formed by different configurations. An equivalence between Schwarzschild and Schwarzschild-Anti-de Sitter wormholes in terms of…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Remo Garattini

A simple model of spacetime foam, made by two different types of wormholes in a semiclassical approximation, is taken under examination: one type is a collection of $N_{w}$ Schwarzschild wormholes, while the other one is made by…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Remo Garattini

A simple model of spacetime foam, made by $N$ wormholes in a semiclassical approximation, is taken under examination. The Casimir-like energy of the quantum fluctuation of such a model and its probability of being realized are computed.…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Remo Garattini

We re-examine the brick-wall model in the context of spacetime foam. In particular we consider a foam composed by wormholes of different sizes filling the black hole horizon. The contribution of such wormholes is computed via a scale…

General Relativity and Quantum Cosmology · Physics 2016-12-21 Remo Garattini

An approximate model of the spacetime foam is offered in which each quantum handle (wormhole) is a 5D wormhole-like solution. A spinor field is introduced for an effective description of this foam. The topological handles of the spacetime…

General Relativity and Quantum Cosmology · Physics 2007-05-23 V. Dzhunushaliev

Hawking's spacetime foam model predicts that due to quantum fluctuations, spacetime is filled with black hole like objects. We argue that Hawking's model implies a cosmological constant of the observed order and that it can also be used to…

General Relativity and Quantum Cosmology · Physics 2018-10-24 Benjamin Schulz

This paper summarizes the contribution presented at the IX Marcel Grossmann Meeting (Rome, July 2000). A simple model of spacetime foam, made by $N$ Schwarzschild wormholes in a semiclassical approximation, is here proposed. The…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Remo Garattini

We conjecture that the neutral black hole pair production is related to the vacuum fluctuation of pure gravity via the Casimir-like energy. A generalization of this process to a multi-black hole pair is considered. Implications on the…

High Energy Physics - Theory · Physics 2007-05-23 Remo Garattini

An effective model for the spacetime foam is constructed in terms of nonlocal interactions in a classical background. In the weak-coupling approximation, the evolution of the low-energy density matrix is determined by a master equation that…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Luis J. Garay

A model of space-time foam, made by $N$ wormholes is considered. The Casimir energy leading to such a model is computed by means of the phase shift method which is in agreement with the variational approach used in Refs.[9-14]. The…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Remo Garattini

A simple model of spacetime foam, made by N wormholes in a semiclassical approximation, is taken under examination. The Casimir-like energy of the quantum fluctuation of such a model and its probability of being realized are computed.…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Remo Garattini

We conjecture that the neutral black hole pair production is related to the vacuum fluctuation of pure gravity via the Casimir-like energy. Implications on the foam-like structure of spacetime are discussed.

General Relativity and Quantum Cosmology · Physics 2009-10-31 Remo Garattini

Spacetime undergoes quantum fluctuations, giving rise to spacetime foam, a.k.a. quantum foam. We discuss some properties of spacetime foam, and point out the conceptual interconnections in the physics of quantum foam, black holes, and…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Y. Jack Ng

An approximate model of the spacetime foam is offered in which a quantum handle (wormhole) is a 5D wormhole-like solution. Neglecting the linear sizes of the wormhole throat we can introduce a spinor field for an approximate and effective…

General Relativity and Quantum Cosmology · Physics 2009-10-31 V. Dzhunushaliev

We consider a spacetime foam model of the Schwarzschild horizon, where the horizon consists of Planck size black holes. According to our model the entropy of the Schwarzschild black hole is proportional to the area of its event horizon. It…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Jarmo Makela , Ari Peltola

Due to quantum fluctuations, spacetime is foamy on small scales. The degree of foaminess is found to be consistent with the holographic principle. One way to detect spacetime foam is to look for halos in the images of distant quasars.…

General Relativity and Quantum Cosmology · Physics 2009-05-01 Y. Jack Ng

A new solution has been presented for the spherically symmetric space time describing wormholes with Phantom Energy. The model suggests that the existence of wormhole is supported by arbitrarily small quantity of Phantom Energy.

General Relativity and Quantum Cosmology · Physics 2009-11-11 F. Rahaman , M. Kalam , M. Sarker , K. Gayen
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