相关论文: Entropy from the foam II
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…
A simple model of spacetime foam, made by N wormholes in a semiclassical approximation, is taken under examination. We show that the Bekenstein-Hawking entropy is here ``quantized'' in agreement with the heuristic calculation of Bekenstein.
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…
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.…
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.…
A simple model of spacetime foam, made by spherically symmetric wormholes, with or without a cosmological term is proposed. The black hole area quantization and its consequences are examined in this context. We open the possibility of…
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…
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…
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…
We propose a way to describe the origin of black hole entropy in the spin foam models of quantum gravity. This stimulates a new way to study the relation of spin foam models and loop quantum gravity.
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…
The spacetime foam structure is reviewed briefly (topogical fluctuations and virtual black hole possibility; equation of state of the foam). A model of space foam at the surface of the event horizon is introduced. The model is applied to…
Recently an idea for computing the entropy of black holes in the spin foam formalism has been introduced. Particularly complete calculations for the three dimensional euclidean BTZ black hole were done. The whole calculation is based on…
We present a microscopical explanation of the entropy of the BTZ black hole using discrete spin foam models of quantum gravity. The entropy of a black hole is given in geometrical terms which lead us to think that its statistical…
A simple model of spacetime foam, made by $N$ Reissner-Nordstr\"{o}m wormholes with a magnetic and electric charge in a semiclassical approximation, is taken under examination. The Casimir-like energy of the quantum fluctuation of such a…
We shall try to exhibit a relation between black hole entropy and topological entropy using the famous Baum-Connes conjecture for foliated manifolds which are particular examples of noncommutative spaces. Our argument is qualitative and it…
We calculate the intrinsic entropy of a Schwarzschild black hole in an asymptotically antide Sitter space. The statistical calculation of the entropy is based on a model for particle structure that leads to confinement. The constituents of…
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…
The Bekenstein-Hawking formula relates the black hole entropy and horizon area. Semiclassical entropy computations have relied on an action principle that fixes a gauge dependent and classically unobservable boundary three-geometry and…
An alternative method to compute the entropy of de Sitter spacetime for dimensions higher than or equal to five is presented. It is shown that de Sitter entropy may be obtained from the Bekenstein-Hawking entropy of a lower-dimensional…