Related papers: Interacting universes and the cosmological constan…
We consider a multiverse scenario made up of classically disconnected regions of the space-time that are, nevertheless, in a quantum entangled state. The addition of a scalar field enriches the model and allows us to treat both the…
In models of hierarchical structure formation, interactions and mergers at high redshift play a key role in the formation and evolution of galaxies. Numerical modeling and observations of nearby systems explore the detailed physics of…
It is pointed out that a collider experiment involves a local contribution to the energy-momentum tensor, a circumstance which not a common feature of the current state of the Universe at large characterized by the cosmological constant…
This paper is the second of two papers devoted to the study of the evolution of the cosmological horizons (particle and event horizons). Specifically, in this paper we consider the extremely general case of an accelerated universe with…
We consider a higher dimensional gravity theory with a negative kinetic energy scalar field and a cosmological constant. We find that the theory admits an exact cosmological solution for the scale factor of our universe. It has the feature…
We discuss the properties of a cosmology dominated by a charged scalar field with a repulsive, long-range self-interaction. The interaction, in the form of a vector field with a tiny mass, can have a dramatic effect on the evolution of the…
We deal with a dynamical mechanism in which a large cosmological constant, as suggested by inflationary scenarios, decays due to expansion of the universe. This mechanism has its origin in the gravitational coupling of the vacuum density.…
Quintessence -- the energy density of a slowly evolving scalar field -- may constitute a dynamical form of the homogeneous dark energy in the universe. We review the basic idea in the light of the cosmological constant problem. Cosmological…
The existence of multiple regions of space beyond the observable Universe (within the so-called "multiverse") where the vacuum energy density takes different values, has been postulated as an explanation for the low non-zero value observed…
For several independent reasons, the idea that notorious sources of entropy could exist in the Universe has been recently revived. Taking advantage of a new framework accounting for non-equilibrium processes in cosmology, we explicitly…
The possibility that the universe may have a fundamental and positive cosmological constant has motivated an interesting cosmological model, in which initially the universe is in a cosmological constant sea, then the local quantum…
What if the dark sector is not a static entity but rather a dynamic entity with interactive components of the universe? This intriguing hypothesis raises important questions regarding the phenomenological behaviour of such an evolving…
Complex systems throughout Nature display structures and functions that are built and maintained, at least in part, by optimal energies flowing through them--not specific, ideal values, rather ranges in energy rate density below which…
From an observational perspective cosmology is today in excellent shape - advances in instrumentation and data processing have enabled us to study the universe in detail back to when the first galaxies formed, map the fluctuations in the…
The mechanism for the relaxation of the cosmological constant is studied and elaborated. In the model used for the analysis of the relaxation mechanism the universe contains two components: a cosmological constant of an arbitrary size and…
To understand galaxies and their evolution, it is necessary to describe how the different scales interact: how the microscopic physics, such as star formation, or the large scale physics, such as galaxy interactions may modify the galaxy…
We discuss the large-scale structure of the universe in inflationary cosmology and the implications that it may have for the long-term future of civilizations. Although each civilization is doomed to perish, it may be possible to transmit…
Coupling any interacting quantum mechanical system to gravity in one (time) dimension requires the cosmological constant to belong to the matter energy spectrum and thus to be quantised, even though the gravity sector is free of any quantum…
We derive analytic expressions for the interaction energy between two general $U(1)$ cosmic strings as the function of their relative orientation and the ratio of the coupling constants in the model. The results are relevant to the…
The presently accelerating universe may keep accelerating forever, eventually run into the event horizon problem, and thus be in conflict with the superstring idea. In the other way around, the current accelerating phase as well as the fate…