Related papers: A New Perspective to Cosmic Evolution and Vacuum S…
Flat space cosmology spacetimes are exact time-dependent solutions of 3-dimensional gravity theories, such as Einstein gravity or topologically massive gravity. We exhibit a novel kind of phase transition between these cosmological…
Within the framework of flux compactifications, we construct an instanton describing the quantum creation of an open universe from nothing. The solution has many features in common with the smooth 6d bubble of nothing solutions discussed…
Big Bang models of the Universe predict rapid domination by curvature, a paradox known as the flatness problem. Solutions to this problem usually leave the Universe exactly flat for every practical purpose. Explaining a nearly but not…
Evolution of a universe with homogeneous extra dimensions is studied with the benefit of a well-chosen parameter space that provides a systematic, useful, and convenient way for analysis. In this model we find a natural evolution pattern…
A perfect fluid, spatially flat cosmology in a $f(T)$ model, derived from a recently proposed general Born-Infeld type theory of gravity is studied. Four dimensional cosmological solutions are obtained assuming the equation of state…
In this talk, we discuss the possibility that the vacuum is dynamically determined in the history of the universe. The point is that some of the bubbles with a certain vacuum shrink by the evolution of the universe via gravity and may…
Cosmology is undergoing an explosive period of activity, fueled both by new, accurate astrophysical data and by innovative theoretical developments. Cosmological parameters such as the total density of the Universe and the rate of…
On the occasion of a century from the proposal of General relativity by Einstein, I attempt to tackle some open issues in modern cosmology, via a toy but non-trivial model. Specifically, I would like to link together: (i) the smallness of…
After 45 years since the discovery of quantum-gravitational birth of the cosmological density perturbations we can try to answer the main question of cosmology what is the origin of the Universe. This has become possible because the…
We "explain", using a Classical approach, how the Universe was created out of "nothing", i.e., with no input of initial energy nor mass. The inflationary phase, with exponential expansion, is accounted for, automatically, by our equation of…
A simple and surprisingly realistic model of the origin of the universe can be developed using the Friedmann equation from general relativity, elementary quantum mechanics, and the experimental values of h, c, G and the proton mass. The…
It is shown that the dark energy presently observed in our universe can be regarded as the energy of a scalar field driving an inflation-like expansion of a multiverse with ours being a subuniverse among other parallel universes. A simple…
A new vision of the beginning and expansion of our universe has produced a solution to the vacuum energy problem (also known as "cosmological constant problem"). A new dynamic of cellular spaces and a discrete time has space being produced…
We study the dynamics of the quantum scalar field responsible for inflation in different epochs of the evolution of the universe by using a recently introduced nonperturbative formalism from a 5D apparent vacuum.
In our previous paper \cite{8}, we proposed a cosmological model from the emergence of space, which possesses a significant character of evaluating the vacuum energy from the Hubble constant and the age of universe. And one problem of this…
Modern astronomical observations in cosmology provide increasingly strong evidence that the expansion of the Universe is accelerating. Explanations of the cosmic acceleration within the framework of general relativity use the hypothesis…
We consider anisotropic cosmological models with an universe of dimension 4 or more, factorized into n>1 Ricci-flat spaces, containing an m-component perfect fluid of m non-interacting homogeneous minimally coupled scalar fields under…
In this paper, we investigate the evolution of the early universe within an emergent fractional cosmological framework. The underlying formulation is conceptually rooted in generalized measure constructions, closely related to fractal…
There are now two cosmological constant problems: (i) why the vacuum energy is so small and (ii) why it comes to dominate at about the epoch of galaxy formation. Anthropic selection appears to be the only approach that can naturally resolve…
We discuss phenomenology of quantum vacuum. Phenomenology of macroscopic systems has three sources: thermodynamics, topology and symmetry. Thermodynamics of the self-sustained vacuum allows us to treat the problems related to the vacuum…