Related papers: Does Chaotic Mixing Facilitate Omega<1 Inflation?
Cosmic inflation is envisioned as the ``most likely'' start for the observed universe. To give substance to this claim, a framework is needed in which inflation can compete with other scenarios and the relative likelihood of all scenarios…
Cosmological inflation and topological defects have been considered for a long time, either in disagreement or in competition. On the one hand an inflationary era is required to solve the shortcomings of the hot big bang model, while on the…
The chaotic inflationary model of the early universe, proposed by Linde is explored in the brane world considering matter described by a minimally coupled self interacting scalar field. We obtain cosmological solutions which admit evolution…
We consider a universe with a bulk viscous cosmic fluid, in a flat Friedmann-Lemaitre-Robertson-Walker geometry. We derive the conditions for the existence of inflation, and those which at the same time prevent the occurrence of…
We study the problem of initial conditions for slow-roll inflation along a plateau-like scalar potential within the framework of fluctuation-dissipation dynamics. We consider, in particular, that inflation was preceded by a…
Cosmologists have developed a phenomenally successful picture of structure in the universe based on the idea that the universe expanded exponentially in its earliest moments. There are three pieces of evidence for this exponential expansion…
Positively-curved, oscillatory universes are studied within the context of Loop Quantum Cosmology subject to a consistent semi-classical treatment. The semi-classical effects are reformulated in terms of an effective phantom fluid with a…
We propose an intuitive framework for studying the problem of initial conditions in slow-roll inflation. In particular, we consider a universe at high, but sub-Planckian energy density and analyze the circumstances under which it is…
We propose yet another solution to the initial condition problem of inflation associated with homogeneity beyond the horizon at the onset of inflation, in cases where inflation is preceded by a radiation era. One may argue that causality…
We propose a version of chaotic inflation, in which a fundamental scale M, well below the Planck scale M_P, fixes the initial value of the effective potential. If this scale happens to be the scale of grand unified theories, there are just…
We study oscillatory universes within the context of Loop Quantum Cosmology. We make a comparative study of flat and positively curved universes sourced by scalar fields with either positive or negative potentials. We investigate how…
It is generally believed that inflationary cosmology explains the isotropy, large scale homogeneity and flatness as well as predicting the deviations from homogeneity of our universe. We show that this is not the only cosmology which can…
We study chaotic inflation driven by a real, massive, homogeneous minimally coupled scalar field in a flat Robertson-Walker spacetime. The semiclassical limit for gravity is considered, whereas the scalar field is treated quantum…
The standard model of cosmology is based on the hot Big Bang theory and the inflationary paradigm. Recent precise observations of the temperature and polarization anisotropies in the cosmic microwave background and the matter distribution…
On the one hand, inflation is an extremely convincing scenario: it solves most cosmological paradoxes and generates fluctuations that became the seeds for the growth of structures. It, however, suffers from a "naturalness" problem:…
Recent cosmic microwave background observations favor low energy scale inflationary models in a closed universe. However, onset of inflation in such models for a closed universe is known to be severely problematic. In particular, such a…
The shortcomings of the Standard Big Bang Cosmological Model as well as their resolution in the context of inflationary cosmology are discussed. The inflationary scenario and the subsequent oscillation and decay of the inflaton field are…
In simple inflationary cosmological scenarios the near-exponential growth can be followed by a long period in which the Universe is dominated by the oscillating inflaton condensate. The condensate is initially almost homogeneous, but…
The entropy of the observable universe is increasing. Thus, at earlier times the entropy was lower. However, the cosmic microwave background radiation reveals an apparently high entropy universe close to thermal and chemical equilibrium. A…
Inflation provides a unified paradigm for understanding the isotropy of the cosmic microwave background (CMB), the flatness problem, and the origin of large-scale structure. Although the physics responsible for inflation is not yet well…