Related papers: Space Time Matter inflation
In this letter assuming a 5D quantum pre-inflationary vacuum energy, we propose a manner to extend some $\Lambda(t)$-CDM models to the inflationary period by using dynamical foliations of the five-dimensional (5D) Ricci-flat space-time…
We consider the Standard Models of particle physics and hot big bang cosmology, and review the theoretical and experimental motivations for extending these models to include supersymmetry and inflation. An obvious extension would be to…
A new idea of deriving a cosmological term from an underlying theory has been proposed in order to explain the expansion history of the universe. We obtain the scale factor with this derived cosmological term and demonstrate that it…
Starting from the inhomogeneous shear--free Nariai metric we show, by solving the Einstein--Klein--Gordon field equations, how a self--interacting scalar field plus a material fluid, a variable cosmological term and a heat flux can drive…
We review the paradigm of eternal inflation in the light of the recently proposed corpuscular picture of space-time. Comparing the strength of the average fluctuation of the field up its potential with that of quantum depletion, we show…
If in a finite universe, the tree-level vacuum is a symmetric superposition of coherent states, in each of which the inflaton field assumes a different, energy-minimizing mean value (vev), then the resulting energy is positive and decreases…
We show that inflation and current cosmic acceleration can be generated by a metric-affine f(R) gravity formulated in the Einstein conformal frame, if the gravitational Lagrangian L(R) contains both positive and negative powers of the…
We consider General Relativity with matter and radiation, one of these fluids being coupled to vacuum. We find that Universe dynamics starts by an inflation phase if the coupled fluid has a negative energy density at early time. Then, there…
Introducing a variable cosmological parameter $\Lambda (t)$ in a geometrical manner from a 5D Riemann-flat metric, we investigate the origin and evolution of primordial magnetic fields in the early universe, when the expansion is governed…
It is sometimes argued that observation of tensor modes from inflation would provide the first evidence for quantum gravity. However, in the usual inflationary formalism, also the scalar modes involve quantised metric perturbations. We…
In a unified picture both inflation and present dynamical dark energy arise from the same scalar field. The history of the Universe describes a crossover from a scale invariant "past fixed point" where all particles are massless, to a…
For simple inflationary models, we provide a consistent and complete scheme by which the macro-physical details of early universe inflation may be determined explicitly from the underlying micro-physical theory. We examine inflationary…
Warm inflationary universe models in the context of intermediate expansion, between power law and exponential, are studied. General conditions required for these models to be realizable are derived and discussed. This study is done in the…
A new class of non-static higher dimensional vacuum solutions in space-time -mass (STM) theory of gravity is found. This solution represent expanding universe without big bang singularity and the higher dimension of these models shrinks as…
Homogeneous isotropic cosmological models with two torsion functions filled with scalar fields and usual gravitating matter are built and investigated in the framework of the Poincar\'e gauge theory of gravity. It is shown that by certain…
We investigate the early-time accelerated universe after the Big Bang. We pay attention to the dissipative properties of the inflationary universe in the presence of a soft type singularity, making use of the parameters of the generalized…
Choosing the three phenomenological models of the dynamical cosmological term $\Lambda$, viz., $\Lambda \sim (\dot a/a)^2$, $\Lambda \sim {\ddot a/a}$ and $\Lambda \sim \rho$ where $a$ is the cosmic scale factor, it has been shown by the…
The homogeneous cosmological model in GR is proposed, where the vacuum energy, which can cause the inflation, is described by tensor field rather than by commonly used in inflationary scenarios scalar field. It is shown that if the initial…
In the early universe it is important to take into account quantum effect of the gravity to explain the feature of the inflation. In this paper, we consider the M-theory effective action which consists of 11 dimensional supergravity and…
We present an interpretation of the physics of space-times undergoing eternal inflation by repeated nucleation of bubbles. In many cases the physics can be interpreted in terms of the quantum mechanics of a system with a finite number of…