Related papers: Spacetime Foam and Vacuum Energy
We develop a number of novel "black-bounce" spacetimes. These are specific regular black holes where the "area radius" always remains non-zero, thereby leading to a "throat" that is either timelike (corresponding to a traversable wormhole),…
It has recently been shown that traversable wormholes may be supported by phantom energy. In this work phantom wormhole geometries are modelled by matching an interior traversable wormhole solution, governed by the equation of state…
We model spacetime foam by a gas of virtual wormholes. For a free scalar field we derive the effective Lagrangian which accounts for the interaction with spacetime foam and contains two additional non-local terms. One term describes the…
We perform a foliation of a four dimensional Riemannian space-time with respect to a discrete time which is an integer multiple of the Planck time. We find that the quantum fluctuations of the metric have a discrete energy spectrum. The…
An approximate model of a spacetime foam is presented. It is supposed that in the spacetime foam each quantum handle is like to an electric dipole and therefore the spacetime foam is similar to a dielectric. If we neglect of linear sizes of…
Due to quantum fluctuations, spacetime is foamy on small scales. For maximum spatial resolution of the geometry of spacetime, the holographic model of spacetime foam stipulates that the uncertainty or fluctuation of distance $l$ is given,…
We consider a possibility that the formally infinite vacuum energy of the quantized matter fields could be stored into Planck-size quantum black holes acting as the fundamental constituents of space and time. Using the recently proposed…
Due to quantum fluctuations, probed at small scales, spacetime is very complicated -- something akin in complexity to a turbulent froth which the late John Wheeler dubbed quantum foam, aka spacetime foam. Our recent work suggests that (1)…
A wormhole with a quantum throat on the basis of an approximate model of the spacetime foam is presented. An effective spinor field is introduced for the description of the spacetime foam. The consequences of such model of the wormhole is…
Wheeler's spacetime foams (wormholes) at the Planck length undergo quantum nucleation, oscillation and annihilation. Their collective excitations over foamy spacetime interact with field operators at large distances. We describe such…
We assume the space-time foam picture in which the vacuum is filled with a gas of virtual wormholes. It is shown that virtual wormholes form a finite (of the Planckian order) value of the energy density of zero-point fluctuations. However…
On general grounds, one may argue that a black hole stops radiation at the Planck mass, where the radiated energy is comparable to the black hole's mass. And also, it has been argued that there would be a "wormhole-like" structure, known as…
We consider a possibility to construct a quantum-mechanical model of spacetime, where Planck size quantum black holes act as the fundamental constituents of space and time. Spacetime is assumed to be a graph, where black holes lie on the…
We model spacetime foam by a gas of virtual wormholes. Then applying an external field one may change the density of virtual wormholes and try to organize a wormhole-like structure in space. The relation between an additional distribution…
On the quantum stage spacetime had the foam-like structure. When the Universe cools the foam structure temperes and therefore the Friedman model represents only the mean picture. We show that effects of the foamed structure we observe now…
We investigate the consequences for the black hole area of introducing fractal structure for the horizon geometry. We create a three-dimensional spherical analogue of a 'Koch Snowflake' using a infinite diminishing hierarchy of touching…
The cosmological constant problem is a fundamental issue that has puzzled researchers in the fields of theoretical physics and cosmology for a long time. It arises from the discrepancy between the observed value of the cosmological constant…
The space-time foam formulas, quoted below in Eqs (1) and (3), express the minimal amount of quantum uncertainty to be introduced into the structure of the Einsteinian space-time in order to make that structure compatible with quantum…
The simplistic model of the classical spacetime foam is considered, which consists of static wormholes embedded in Minkowski spacetime. We explicitly demonstrate that such a foam structure leads to a topological bias of point-like sources…
We present an effective theory to describe the quantization of spherically symmetric vacuum in loop quantum gravity. We include anomaly-free holonomy corrections through a canonical transformation of the Hamiltonian of general relativity,…